Class 5 Science MCQs

Correct Option: (a) Similar
Explanation: Organisms with similar characteristics are placed in the same group to make classification easier and more organized.

Correct Option: (d) Classification
Explanation: Classification is arranging organisms into groups based on their similarities and differences.

Correct Option: (d) Kingdom
Explanation: The largest groups of organisms, which are classified based on common characteristics, are called kingdoms.

Correct Option: (b) Five
Explanation: Organisms are classified into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia.

Correct Option: (a) One
Explanation: Monera are single-celled organisms, so they are made up of only one cell.

Correct Option: (a) Simple
Explanation: Monera has a simple structure compared to other organisms.

Correct Option: (d) Bacteria
Explanation: Bacteria are a type of Monera, along with other organisms like cyanobacteria.

Correct Option: (c) Bacterium
Explanation: The singular form of “Bacteria” is “Bacterium”.

Correct Option: (c) Water
Explanation: Protista are typically found in water habitats, although some can also be found in moist terrestrial environments.

Correct Option: (b) Protista
Explanation: Amoeba, Paramecium, and Algae are examples of Protista.

Correct Option: (a) One cell
Explanation: Amoeba and paramecium are examples of unicellular organisms, because they are made up of only one cell. However, Spirogyra is a multicellular Algae, composed of many cells arranged in a filamentous structure. Amoeba and paramecium carry out all life processes, such as respiration, digestion, and reproduction, within a single cell.

Correct Option: (d) Algae
Explanation: Algae can be unicellular, like Chlamydomonas, or multicellular, like Spirogyra.

Correct Option: (c) Moist
Explanation: Fungi typically thrive in moist environments.

Correct Option: (d) Fungi
Explanation: Fungi do not have chlorophyll and cannot perform photosynthesis.

Correct Option: (a) No
Explanation: Fungi lack chlorophyll, which is necessary for photosynthesis.

Correct Option: (a) Yeast
Explanation: Yeast is a type of fungus that is typically used in baking and brewing.

Correct Option: (c) Rhizopus
Explanation: Rhizopus is a common type of black bread mold.

Correct Option: (c) Fungi
Explanation: Mushroom is a type of fungus.

Correct Option: (b) Mushroom
Explanation: Mushrooms are a type of fungi that can grow to a large size.

Correct Option: (d) Plantae
Explanation: Organisms in the kingdom Plantae, which includes plants, have chlorophyll and can perform photosynthesis.

Correct Option: (b) Animalia
Explanation: Organisms in the kingdom Animalia are animals.

Correct Option: (a) Plantae
Explanation: Organisms in the kingdom Plantae (plants) have chlorophyll.

Correct Option: (b) Two
Explanation: Flowering plants are divided into two main groups: monocots and dicots.

Correct Option: (a) Monocot plant
Explanation: Monocot plants have seeds with one cotyledon.

Correct Option: (a) Monocot plant
Explanation: These plants have seeds with one cotyledon and are examples of monocots.

Correct Option: (b) Dicot plant
Explanation: Dicot plants have seeds with two cotyledons.

Correct Option: (b) Dicot plant
Explanation: These plants have seeds with two cotyledons and are examples of dicots.

Correct Option: (b) Two
Explanation: Animals can be divided into two main groups based on the presence or absence of a backbone: vertebrates and invertebrates.

Correct Option: (c) Backbone
Explanation: Vertebrates are the animals that have a backbone.

Correct Option: (b) Internal
Explanation: Vertebrates have an internal skeleton made of bones.

Correct Option: (b) Three
Explanation: The body of vertebrates is typically divided into three main parts: the head, abdomen, and tail.

Correct Option: (d) All of these
Explanation: The body of vertebrates consists of the head, trunk, and tail.

Correct Option: (d) All of these
Explanation: Different vertebrate groups have different skin coverings: fish have scales, birds have feathers, and mammals have hair.

Correct Option: (b) Invertebrates
Explanation: Invertebrates are the animals that do not have a backbone.

Correct Option: (d) Five
Explanation: Based on their skeletal structure, vertebrates are divided into five main groups: fishes, amphibians, reptiles, birds, and mammals. Each group has distinct characteristics that set it apart from the others.

Correct Option: (c) Scales
Explanation: Fish have scales on their skin, which provide protection and reduce water resistance as they move through the water. These scales can vary in size, shape, and arrangement depending on the fish species.

Correct Option: (b) Gills
Explanation: Fish breathe through gills, specialized organs for gas exchange in water.

Correct Option: (b) Eggs
Explanation: Most fish reproduce by laying eggs.

Correct Option: (b) Amphibians
Explanation: Amphibians are vertebrates that can live both on land and in water.

Correct Option: (d) Respire
Explanation: Amphibians can respire through both their lungs and their skin. Their skin is thin and moist, allowing for the exchange of gases, such as oxygen and carbon dioxide, between the environment and their bloodstream. In addition to skin respiration, many amphibians also have lungs, which they use to breathe air when they are on land.

Correct Option: (c) Water
Explanation: Amphibians typically lay their eggs in water.

Correct Option: (b) Amphibians
Explanation: These are all examples of amphibians.

Correct Option: (c) Water
Explanation: Amphibians depend on water for reproduction and development because they lay their eggs in water and typically develop their larvae in water.

Correct Option: (c) Reptiles
Explanation: Reptiles are often called creeping animals because they move by creeping or crawling on the ground.

Correct Option: (b) Land
Explanation: Reptiles typically lay their eggs on land.

Correct Option: (b) Eggs
Explanation: Reptiles reproduce by laying eggs.

Correct Option: (c) Reptiles
Explanation: These are all examples of reptiles.

Correct Option: (c) Reptiles
Explanation: Dinosaurs were a type of animal that lived a long time ago. They were big and walked on land. There were many different kinds of dinosaurs, some small and some huge. They were reptiles, which means they had scales and laid eggs. However, they are not around anymore. They disappeared a long time ago, but some of their relatives, like birds, are still alive today.

Correct Option: (c) Both (a) & (b)
Explanation: Birds have feathers and beaks.

Correct Option: (b) Hollow
Explanation: The bones of birds are hollow, which makes them lightweight and suited for flight.

Correct Option: (b) Hollow bones
Explanation: Bird bones are hollow, which makes them lightweight and helps birds fly more easily. Hollow bones also provide support and strength while reducing the overall weight of the bird’s skeleton. This adaptation allows birds to have a strong, lightweight skeleton that is well-suited for flight.

Correct Option: (c) Running birds
Explanation: Some birds, like ostriches, emus, and cassowaries, have strong legs and are unable to fly. Instead, they are known as running birds because they use their powerful legs to run quickly on the ground. These birds have evolved to be fast runners and rely on their speed to escape predators and find food.

Correct Option: (c) Running
Explanation: Kiwi and ostrich are examples of running birds.

Correct Option: (d) Duck
Explanation: Ducks have webbed feet, which help them swim. Webbed feet are feet with skin stretched between the toes. This allows animals, such as ducks, swim better by increasing the surface area of their feet, allowing them to push more water and move through the water with greater ease.

Correct Option: (c) Eagle
Explanation: The largest flying bird is the Albatross.

Correct Option: (d) Hummingbird
Explanation: The smallest bird in the world is the bee hummingbird, which measures about 2.0 inches (5.1 cm) in length and weighs about 0.07 ounces (2.0 grams).

Correct Option: (c) Hawk
Explanation: Hawks are known for their hunting skills.

Correct Option: (c) Snow
Explanation: Penguins are found in cold climates, typically in Antarctica.

Correct Option: (a) Woodpeckers
Explanation: Woodpeckers are known for their ability to peck holes in tree trunks.

Correct Option: (b) Dinosaur
Explanation: Birds have evolved from a generation of carnivore dinosaurs. This is supported by considerable fossil evidence and scientific research, which suggests that modern birds are direct descendants of theropod dinosaurs, a group of bipedal, mostly carnivorous dinosaurs that includes well-known species like Velociraptor and Tyrannosaurus rex.

Correct Option: (c) Aviary
Explanation: A bird park is a place where birds are kept and usually displayed to the public. These parks often have large enclosures or aviaries, large cages or nets where birds can fly freely and interact with each other.

Correct Option: (d) Mammals
Explanation: Mammals are characterized by the presence of mammary glands, which produce milk for their young, and the presence of hair or fur.

Correct Option: (b) Birth to young one
Explanation: Mammals give birth to live young ones.

Correct Option: (d) Mammals
Explanation: These are all examples of mammals.

Correct Option: (b) Bat
Explanation: Bats are flying mammals.

Correct Option: (d) Platypus
Explanation: Platypus is a mammal that lays eggs but produces milk to feed its young ones.

Correct Option: (a) Kangaroo
Explanation: Kangaroos have a pouch that they carry and nurse their young.

Correct Option: (c) Both (a) & (b)
Explanation: Birds and mammals are classes of vertebrate animals, with birds belonging to the class Aves and mammals belonging to the class Mammalia.

Correct Option: (d) Sponges
Explanation: Sponges are invertebrates that belong to the phylum Porifera.

Correct Option: (a) Pores
Explanation: Sponges have pores on their body for water intake and canals for water circulation.

Correct Option: (b) Canals
Explanation: Sponges have an internal canal system for water circulation.

Correct Option: (a) Aquatic
Explanation: Sponges are aquatic animals, meaning they live in water.

Correct Option: (b) Soft-bodied
Explanation: Worms have soft bodies.

Correct Option: (c) Round
Explanation: Worms have round and cylindrical bodies.

Correct Option: (d) No
Explanation: Worms do not have legs.

Correct Option: (a) Earthworm and tapeworm
Explanation: Earthworms and tapeworms have segmented bodies.

Correct Option: (b) Flatworm and roundworm
Explanation: Flatworms and roundworms do not have segmented bodies.

Correct Option: (c) Insects
Explanation: Insects are invertebrates, meaning they do not have a backbone.

Correct Option: (d) All of these
Explanation: The body of insects is divided into three main parts: head, thorax, and abdomen.

Correct Option: (b) Three
Explanation: Insects typically have six legs divided into three pairs.

Correct Option: (b) Three
Explanation: The body of insects is divided into three parts: head, thorax, and abdomen.

Correct Option: (c) Both (a) & (b)
Explanation: The exoskeleton of insects both protects and supports the body.

Correct Option: (a) Stick insects
Explanation: Stick insects are green or brown and look like sticks. They are also known as walking sticks.

Correct Option: (c) Walking
Explanation: Stick insects are also known as walking sticks or stick-bugs.

Correct Option: (b) Invertebrates
Explanation: Molluscs are invertebrates.

Correct Option: (b) Soft-bodied
Explanation: Molluscs typically have soft bodies.

Correct Option: (b) Molluscs
Explanation: These are all examples of molluscs.

Correct Option: (c) Both snail & oyster
Explanation: Both snails and oysters have shells.

Correct Option: (d) Octopus
Explanation: Octopuses are molluscs that do not have a shell. They have a soft body and a flexible, muscular mantle that allows them to squeeze through tight spaces and move quickly in the water. Octopuses are known for their ability and intelligence to change the color and texture to blend in with their surroundings.

Correct Option: (c) Pearl
Explanation: When a grain of salt or sand enters the body of an oyster, the oyster may form a pearl around it as a defense mechanism.

Correct Option: (b) Invertebrates
Explanation: Echinoderms are invertebrates.

Correct Option: (d) Ocean
Explanation: Echinoderms are exclusively found in marine environments.

Correct Option: (c) Echinoderms
Explanation: Echinoderms do not have a distinct head region.

Correct Option: (c) Echinoderms
Explanation: Echinoderms have a spiny covering.

Correct Option: (c) Echinoderms
Explanation: These are all examples of echinoderms.

Correct Option: (c) Biodiversity
Explanation: Biodiversity refers to the variety of life forms present in a particular place.

Correct Option: (c) Extinct
Explanation: Extinct species are those that no longer exist.

Correct Option: (c) Extinct
Explanation:Dinosaurs are considered extinct animals because they no longer exist today. They went extinct approximately 65 million years ago, likely due to many factors, including a massive asteroid impact, volcanic activity, climate change, and possibly disease. These events disrupted ecosystems, leading to the collapse of food chains and the eventual extinction of most dinosaur species.

Correct Option: (b) Endangered
Explanation: Endangered species are those at risk of becoming extinct.

Correct Option: (d) Endangered
Explanation: The Bengal tiger and panda are endangered species.

Correct Option: (d) Endangered
Explanation: These are all examples of endangered animals in Pakistan.

Correct Option: (a) Blind
Explanation: The Indus Dolphin has poor eyesight and relies on echolocation to navigate.

Correct Option: (c) Both (a) & (b)
Explanation: Both terms are used to describe large areas set aside for wildlife conservation.

Correct Option: (d) Coastal areas
Explanation: Mangroves are typically found in coastal areas, where they are adapted to saline conditions.

Correct Option: (d) Marine
Explanation: Mangroves provide a safe habitat for marine animals, especially during their juvenile stages.

Correct Option: (b) Conserving biodiversity
Explanation: Conserving biodiversity involves protecting habitats and species, which can help prevent extinction.

Correct Option: (a) Web
Explanation: The foot of an aquatic bird is webbed, meaning its toes are connected by a thin layer of skin, making it easier for them to swim. This webbing helps increase the surface area of their feet, allowing them to push more water and move through it with greater ease.

Correct Option: (d) Mammals
Explanation: Cats are mammals.

Correct Option: (a) Gills
Explanation: Fish typically respire through their gills, which extract oxygen from water.

Correct Option: (b) Two
Explanation: Gram seeds are dicots, meaning they have two cotyledons.

Correct Option: (c) Echinoderms
Explanation: Echinoderms, like starfish, sea urchins, and sea cucumbers, are found exclusively in marine environments.

Correct Option: (b) Microorganism
Explanation: Microorganisms are organisms that are too small to be seen without a microscope.

Correct Option: (c) Microscope
Explanation: A microscope is an instrument used to view objects that are too small to be seen with the naked eye.

Correct Option: (b) Microorganism
Explanation: Both viruses and bacteria are types of microorganisms.

Correct Option: (b) Tiny
Explanation: Viruses are indeed tiny, much smaller than bacteria.

Correct Option: (c) Both living and nonliving
Explanation: Viruses are a link between living and nonliving things. They can reproduce only within an organism. Out of the body of an organism, they are nonliving.

Correct Option: (d) Organism
Explanation: Viruses need a host organism to reproduce.

Correct Option: (d) Organism
Explanation: Viruses are tiny particles that need a living thing, like a plant, animal, or bacteria, to survive and reproduce. They can’t live on their own. Once inside a living thing, they take over the cells to make more copies of themselves. So, viruses are found living inside organisms.

Correct Option: (a) Nonliving things
Explanation: Viruses are considered nonliving when outside of a host organism.

Correct Option: (d) All of these
Explanation: Viruses can cause diseases in all types of living organisms.

Correct Option: (b) Harmful
Explanation: While some viruses may have useful applications, many are harmful and cause diseases in their host organisms.

Correct Option: (b) Virus
Explanation: Hepatitis, polio, and flu are viral diseases.

Correct Option: (a) Single-celled
Explanation: Bacteria are unicellular microorganisms.

Correct Option: (a) Bacteria
Explanation: These diseases are caused by bacterial infections.

Correct Option: (a) Useful
Explanation: Beneficial bacteria can be found in the human body and in various environments, performing important roles such as aiding digestion and fighting pathogens.

Correct Option: (a) Bacteria
Explanation: Bacteria play a crucial role in the digestion and absorption of food components in the small intestine.

Correct Option: (b) Less
Explanation: While bacteria are ubiquitous, the number of harmful bacteria is relatively small compared to the total number of bacteria.

Correct Option: (a) Number of bacteria is more than the cells
Explanation: There are more bacterial cells in the human body than human cells.

Correct Option: (b) Equal
Explanation: The number of bacteria in a small spoon can be comparable to the population of Africa, highlighting the abundance of bacteria.

Correct Option: (b) Three
Explanation: Bacteria can be classified into three main shapes: Round shaped, Rod shaped, and Spiral shaped.

Correct Option: (d) All of these
Explanation: Bacteria can have a variety of shapes, including round, rod-shaped, and spiral, among others.

Correct Option:
(c) Fungi
Explanation: Fungi are distinct from both plants and animals and have their own unique characteristics.

Correct Option: (b) cannot
Explanation: Fungi are heterotrophic, meaning they cannot produce their own food and must obtain it from other sources.

Correct Option: (b) Decompose
Explanation: Fungi are important decomposers, breaking down organic matter into simpler substances.

Correct Option: (c) Fungi
Explanation: These are fungal infections.

Correct Option: (c) Fungi
Explanation: Yeast is a type of fungus used in baking and brewing, while penicillin is an antibiotic derived from fungi.

Correct Option: (c) Fungi
Explanation: Mushrooms are a type of fungus.

Correct Option: (c) Fungi
Explanation: Mold is a type of fungus.

Correct Option: (b) Decomposers
Explanation: Decomposers are organisms that break down dead or decaying organisms.

Correct Option: (a) Simple
Explanation: Decomposers break down complex organic molecules into simpler compounds.

Correct Option: (a) Increases
Explanation: The activity of decomposers increases with higher temperatures, humidity, and oxygen levels, leading to faster decomposition.

Correct Option: (c) Environment
Explanation: Decomposition releases gases back into the environment.

Correct Option: (d) Pathogens
Explanation: Pathogens are disease-causing microorganisms.

Correct Option: (b) Infectious disease
Explanation: Infectious diseases are caused by pathogens.

Correct Option: (a) Viruses
Explanation: These diseases are caused by viruses.

Correct Option: (b) Bacteria
Explanation: These diseases are caused by bacteria.

Correct Option: (c) Fungi
Explanation: These diseases are caused by fungi.

Correct Option: (b) Transmission
Explanation: These are common modes of transmission for infectious diseases.

Correct Option: (b) airborne
Explanation: Airborne diseases are spread through the air.

Correct Option: (a) waterborne
Explanation: These diseases are transmitted through contaminated water.

Correct Option: (d) Both (b) & (c)
Explanation: Airborne: When an infected person coughs, sneezes, talks, or breathes, tiny droplets containing the virus can float in the air. Others can breathe them in. Direct Contact: Some diseases are transmitted by shaking hands or by touching things used by the patient.

Correct Option: (b) Bacteria
Explanation: Bacteria and yeasts are used in making food items such as bread, cheese, and yogurt.

Correct Option: (b) Yeast
Explanation: Yeast is used to make bread and cheese.

Correct Option: (a) Bacteria
Explanation: Certain types of bacteria are used in the fermentation process to make yogurt.

Correct Option: (b) Bacteria
Explanation: Bacteria are used to decompose toxic materials in sewage and industrial wastewater through a process called biodegradation, helping to clean and treat wastewater before it is released into the environment.

Correct Option: (b) Antibiotics
Explanation: Antibiotics are made using certain fungi and bacteria.

Correct Option: (d) Penicillin
Explanation: Penicillin was the first antibiotic discovered. Alexander Fleming discovered penicillin in 1928.

Correct Option: (b) Penicillium
Explanation: Penicillin was derived from the fungus Penicillium.

Correct Option: (b) Fungi
Explanation: Mushrooms are a type of fungi.

Correct Option: (b) Virus
Explanation: Polio is caused by a virus.

Correct Option: (b) Fungi
Explanation: Penicillin is derived from a type of fungus.

Correct Option: (b) Microorganisms
Explanation: Contamination of food can occur due to the presence of microorganisms.

Correct Option: (d) Ant
Explanation: An ant is not a microorganism; it is an insect.

Correct Option: (d) Flower
Explanation: The flower is the attractive part of a plant that often contains reproductive structures.

Correct Option: (d) Pedicel
Explanation: The pedicel is the stalk of the flower that connects the flower to the stem.

Correct Option: (c) Four
Explanation: The flower typically has four main parts at the pedicel: sepals, petals, stamens, and pistil.

Correct Option: (a) Sepals
Explanation: Sepals are the outermost whorl of the flower and are usually green, serving to protect the flower bud.

Correct Option: (a) Sepals
Explanation: Sepals are the green leaflets of a flower that protect the flower during its budding stage.

Correct Option: (a) Sepals
Explanation: Sepals are leaf-like structures that protect the flower bud before it opens.

Correct Option: (b) Petals
Explanation: Petals are the colored leaflets of a flower that attract pollinators.

Correct Option: (b) Petals
Explanation: The second whorl of a flower is typically composed of petals.

Correct Option: (b) Petals
Explanation: Petals, often brightly colored, attract insects and birds to the flower for pollination.

Correct Option: (c) Stamen
Explanation: The stamen is the male reproductive organ of a flower, typically the third whorl in floral arrangement.

Correct Option: (c) Stamen
Explanation: The stamen consists of the anther, which produces pollen, and the filament, which supports the anther.

Correct Option: (c) Stamen
Explanation: The stamen is the male reproductive part of the flower, consisting of the anther and the filament.

Correct Option: (a) Anther
Explanation: The anther is the round or oval sac-shaped structure where pollen grains are produced.

Correct Option: (a) Anther
Explanation: Pollen grains are formed on the anther, which is part of the stamen.

Correct Option: (b) Filament
Explanation: The filament is the long stalk-shaped structure that supports the anther.

Correct Option: (b) Filament
Explanation: The filament supports the anther, where pollen grains are produced.

Correct Option: (d) Carpel
Explanation: The carpel, also known as the pistil, is the fourth whorl in the flower, consisting of the stigma, style, and ovary.

Correct Option: (d) Carpel
Explanation: The carpel, or pistil, consists of the stigma, style, and ovary, and is the female reproductive part of the flower.

Correct Option: (d) Carpel
Explanation: The carpel, or pistil, is the female reproductive part of the flower, which includes the stigma, style, and ovary.

Correct Option: (d) All of these
Explanation: The carpel, or pistil, consists of the stigma, style, and ovary. These parts work together to facilitate fertilization and seed production in flowering plants.

Correct Option: (a) Stigma
Explanation: The stigma is the bottle-shaped part of the carpel, located at the top of the style. It is the female reproductive organ of the flower that receives pollen during pollination. The stigma is usually sticky or hairy to help trap pollen grains. Once pollen grains land on the stigma, they germinate and grow pollen tubes, which transport the male gametes (sperm) to the ovules (eggs) located in the ovary.

Correct Option: (a) Stigma
Explanation: After pollination, pollen grains adhere to the stigma of the carpel, where they germinate to form the pollen tube.

Correct Option: (b) Style
Explanation: The style is the neck-shaped part of the carpel, located below the stigma and connecting it to the ovary.

Correct Option: (b) Style
Explanation: The pollen tube grows through the style, reaching the ovary, where it fertilizes the ovules.

Correct Option: (c) Ovary
Explanation: The ovary is the oval-shaped part of the carpel that contains the ovules, which develop into seeds after fertilization.

Correct Option: (c) Ovary
Explanation: Ovules are present in the ovary of the flower, where they develop into seeds after fertilization.

Correct Option: (b) Pollination
Explanation: Pollination is the process in which pollen grains are transferred from the anther to the stigma of a flower.

Correct Option: (a) Two
Explanation: There are two main types of pollination: self-pollination, where pollen is transferred within the same flower or between flowers of the same plant, and cross-pollination, where pollen is transferred between flowers of different plants.

Correct Option: (a) Self-Pollination
Explanation: Self-pollination occurs when the pollen grains are transferred from the anther of a flower to the stigma of the same flower or the stigma of another flower of the same plant.

Correct Option: (a) Self-Pollination
Explanation: Self-pollination occurs in plants like pea, cotton, and tomato, where the flowers are designed to ensure that their own pollen fertilizes their ovules.

Correct Option: (b) Cross pollination
Explanation: Cross-pollination occurs when pollen is transferred from the flower of one plant to the stigma of the flower of another plant of the same species.

Correct Option: (b) Cross pollination
Explanation: Cross-pollination occurs in plants like maize, papaya, and rose, where the flowers are designed to encourage the transfer of pollen between different plants of the same species.

Correct Option: (b) Pollination
Explanation: Pollination occurs through various agents such as insects, air, bats, and water, which help transfer pollen from the anther to the stigma of flowers.

Correct Option: (b) More than one
Explanation: The China rose (Hibiscus) has multiple carpels that are fused together to form a single pistil. Each carpel contains an ovary, style, and stigma, but they are united into one structure in the flower. Thus, the flower has more than one carpel.

Correct Option: (b) Reproduction
Explanation: The main difference between living and non-living things is the ability of living things to reproduce and produce offspring of their own kind.

Correct Option: (a) Limited
Explanation: The lifespan of living things is limited, as they undergo a life cycle that includes birth, growth, reproduction, and death.

Correct Option: (b) Living
Explanation: Living things, not non-living things, produce new organisms of their kind through reproduction.

Correct Option: (a) Two
Explanation: There are two main types of reproduction in plants: sexual reproduction and asexual reproduction.

Correct Option: (a) Only one
Explanation: In asexual reproduction, a single parent plant produces new plants that are genetically identical to the parent plant.

Correct Option: (c) Flower
Explanation: In asexual reproduction, flowers do not take any part, as it usually involves vegetative propagation, where new plants are produced from stems, leaves, or roots.

Correct Option: (d) Flowers
Explanation: Flowers do not take part in asexual reproduction, which typically involves vegetative propagation through stems, roots, or leaves.

Correct Option: (a) Great Similarity
Explanation: Plants produced through asexual reproduction usually have a great similarity to the parent plant, as they are genetically identical.

Correct Option: (a) Layer
Explanation: When branches of shrubs become buried in the soil and produce roots, it is called layering.

Correct Option: (a) Layering
Explanation: When branches of shrubs are buried in the soil, produce new roots, and are later cut and separated to develop into new plants, it is called layering.

Correct Option: (c) Both (a) & (b)
Explanation: Layering can occur naturally, where branches of shrubs produce roots, or it can be done artificially by gardeners to propagate plants.

Correct Option: (a) Layering
Explanation: Lemon, jasmine, and lychee can be bred through layering, where branches are buried to produce roots and then cut to develop into new plants.

Correct Option: (c) Tuber
Explanation: A tuber is an underground thick stem of a plant, such as a potato, which stores food and nutrients.

Correct Option: (c) Tuber
Explanation: The potato is an example of a tuber, which is an underground thick stem of a plant that stores food and nutrients.

Correct Option: (c) Tuber
Explanation: The eyes on tubers like potatoes are actually buds, which can grow into new plants under suitable conditions.

Correct Option: (a) New Plants
Explanation: When a piece of potato with eyes (buds) is buried in the ground, new plants can develop from them, as the buds grow into new shoots and roots.

Correct Option: (c) Flower
Explanation: Sexual reproduction typically involves the reproductive organs of a plant, which are found in the flower.

Correct Option: (a) Pollen tube
Explanation: Male gametes, which are contained within pollen grains, are carried to the ovule by the pollen tube during sexual reproduction.

Correct Option: (b) Ovule
Explanation: Female gametes are contained within the ovule, which is located within the ovary of a flower.

Correct Option: (c) Zygote
Explanation: The fusion of male and female gametes during sexual reproduction forms a zygote, which develops into an embryo.

Correct Option: (d) Embryo
Explanation: The zygote undergoes multiple cell divisions to form an embryo during sexual reproduction.

Correct Option: (b) Ovule
Explanation: After fertilization, the ovule develops into a seed, containing the embryo and endosperm.

Correct Option: (b) Seed
Explanation: The ovule develops into a seed after fertilization, containing the embryo and endosperm.

Correct Option: (a) Ovary
Explanation: After fertilization, the ovary ripens to form the fruit, which encloses the seeds.

Correct Option: (b) Two
Explanation: Sexual reproduction involves two parents, a male and a female, contributing genetic material to the offspring.

Correct Option: (b) Sexual
Explanation: In sexual reproduction, male and female gametes fuse to form a zygote, which develops into a new plant.

Correct Option: (a) One
Explanation: Asexual reproduction typically involves a single parent organism.

Correct Option: (a) No
Explanation: In asexual reproduction, there is no fusion of male and female gametes. Instead, the offspring are produced from a single parent organism, and they inherit all of their genetic material from that parent. Asexual reproduction typically involves mechanisms such as binary fission, budding, or fragmentation, where the parent organism produces offspring that are genetically identical to itself.

Correct Option: (a) Asexual
Explanation: In asexual reproduction, the offspring are genetically identical to the parent, resulting in offspring that resemble the parent plant.

Correct Option: (a) Slow
Explanation: Sexual reproduction typically involves multiple steps, including pollination, fertilization, and seed development, which can be a slow process.

Correct Option: (b) Quick
Explanation: Asexual reproduction can be a relatively quick process, as it does not involve the complex steps of pollination, fertilization, and seed development seen in sexual reproduction.

Correct Option: (b) Seed coat
Explanation: The seed coat is the outer covering of a seed that protects the embryo and endosperm.

Correct Option: (b) Testa
Explanation: The seed coat is also known as the testa.

Correct Option: (b) Testa
Explanation: The testa, or seed coat, protects the tiny embryo inside the seed.

Correct Option: (a) Embryo
Explanation: The embryo is the developing plant inside the seed.

Correct Option: (c) Micropyle
Explanation: The micropyle is a small pore in the seed coat that allows water and gases to enter the seed during germination.

Correct Option: (a) Embryo
Explanation: The embryo consists of cotyledons, which are the first leaves of the plant.

Correct Option: (a) Store
Explanation: Cotyledons store food for the developing plant until it can produce its own through photosynthesis.

Correct Option: (d) Radicle
Explanation: The radicle, which is part of the embryo, is the first structure to emerge from the seed during germination and forms the primary root of the plant.

Correct Option: (a) Plumule
Explanation: The plumule, which is part of the embryo, gives rise to the shoot system of the plant.

Correct Option: (c) Germination
Explanation: Germination is the process by which a seedling emerges from the seed and begins to grow.

Correct Option: (c) Micropyle
Explanation: The micropyle, which is a small pore in the seed coat, allows water to enter the seed during germination.

Correct Option: (c) Both a & b
Explanation: Cotyledons provide stored food to both the radicle and plumule during germination.

Correct Option: (c) Leaflets
Explanation: The cotyledons are the first leaves of the plant, and they emerge from the seed during germination.

Correct Option: (a) Monocot
Explanation: Maize is a monocotyledonous plant, which means that it has one cotyledon in its seed.

Correct Option: (b) Absent
Explanation: In gram seeds (which are dicots), the food reserve is stored in the cotyledons rather than in the endosperm. The endosperm is absent in mature gram seeds because it is consumed during seed development.

Correct Option: (b) Dicot
Explanation: Gram is a dicotyledonous plant, which means that it has two cotyledons in its seed.

Correct Option: (a) Present
Explanation: In maize (corn) seeds, the endosperm is present and plays a vital role in storing nutrients for the developing embryo.

Correct Option: (a) Center
Explanation: In a gram seed (which is a dicot seed), the embryo is located in the center, surrounded by the two large cotyledons that store food.

Correct Option: (b) One
Explanation: In a maize seed (which is a monocot seed), the embryo is located on one side, next to the endosperm, which provides nourishment during germination.

Correct Option: (c) Germination
Explanation: Germination is the process by which a seedling emerges from the seed and begins to grow, and it requires water, air, and a suitable temperature.

Correct Option: (c) Cotyledon stores food for embryo
Explanation: In a dicot seed, the cotyledons store food for the developing embryo.

Correct Option: (b) B,C and D
Explanation: The female reproductive parts of a flower are the pistil (carpel), stigma, style, and ovary.

Correct Option: (b) Seed coat
Explanation: The seed coat is the outer covering of a seed, and it protects the seed from damage and dehydration.

Correct Option: (c) Water, temperature, air
Explanation: Seed germination requires water, a suitable temperature, and oxygen (air).

Correct Option: (b) Cross pollination
Explanation: Papaya requires cross-pollination, which means that pollen from one flower must be transferred to the stigma of another flower on a different plant for successful pollination and fruit production.

Correct Option: (d) Environment
Explanation: The term “environment” refers to the surroundings or conditions in which an organism lives or operates.

Correct Option: (d) Pollution
Explanation: Environmental pollution refers to the introduction of harmful substances or pollutants into the environment that cause adverse effects to living organisms.

Correct Option: (c) Pollutants
Explanation: Pollutants are substances that cause pollution by contaminating the environment.

Correct Option: (b) Three
Explanation: The three main types of environmental pollution are air pollution, water pollution, and land pollution.

Correct Option: (d) Acid
Explanation: Acid rain is caused by the release of sulfur dioxide and nitrogen oxides into the atmosphere, which then react with water vapor to form sulfuric acid and nitric acid. This acidic precipitation can harm the environment and living organisms.

Correct Option: (b) Smog
Explanation: Smog is a type of air pollution that forms when pollutant gases, such as nitrogen oxides and volatile organic compounds, react in the atmosphere in the presence of sunlight to form harmful chemicals and particulate matter.

Correct Option: (b) Smog
Explanation: Smog is a type of air pollution that forms when pollutants like nitrogen oxides and volatile organic compounds mix with sunlight. In winter, cold air traps these pollutants near the ground (a phenomenon called temperature inversion), leading to reduced visibility due to smog.

Correct Option: (c) Transparent
Explanation: A greenhouse is typically made of transparent material, such as glass or plastic, to allow sunlight to enter and warm the interior while trapping heat inside.

Correct Option: (d) Vegetables and flowers are grown
Explanation: Greenhouses are used for growing plants, particularly in colder climates or during certain seasons, to provide a controlled environment for optimal growth.

Correct Option: (c) Hot
Explanation: The greenhouse effect allows sunlight to enter the greenhouse and warm the interior, creating a warmer environment compared to the outside temperature, even during winter.

Correct Option: (c) Greenhouse
Explanation: These gases, known as greenhouse gases, absorb and emit heat, contributing to the greenhouse effect and influencing Earth’s climate.

Correct Option: (b) Greenhouse
Explanation: The greenhouse effect is a natural process where certain gases in the Earth’s atmosphere trap heat, allowing sunlight to enter and warm the Earth’s surface while preventing some of the heat from escaping back into space.

Correct Option: (d) All of these
Explanation: Coal, crude oil, and natural gases are all considered fossil fuels as they are formed from the buried remains of plants and animals over millions of years.

Correct Option: (c) Fossil fuel
Explanation: Fossil fuels, such as coal, crude oil, and natural gases, were formed from the buried remains of plants and animals over millions of years.

Correct Option: (a) Global
Explanation: Global warming refers to the increase in the average temperature of the Earth’s atmosphere and oceans, primarily due to the greenhouse effect caused by increased levels of greenhouse gases in the atmosphere.

Correct Option: (b) 2018
Explanation: The Government of Pakistan initiated the “Billion Tree Tsunami Afforestation Project” in 2018 with the goal of planting one billion trees across the country to combat deforestation and climate change.

Correct Option: (a) Biodegradable
Explanation: Biodegradable materials are those that can be broken down by natural processes into simpler substances and become part of the soil. Examples include organic matter like food waste, leaves, and paper.

Correct Option: (b) Non-biodegradable
Explanation: Non-biodegradable materials are those that cannot be broken down by natural processes into simpler substances. Examples include plastic, metals, and glass.

Correct Option: (b) 4R
Explanation: The 4R commonly used are as follows:

• Recycle: Recycle materials such as paper, plastic, glass, and metal to create new products and reduce the need for virgin materials.
• Reuse: Reuse items whenever possible instead of throwing them away.
• Reduce: Reduce the amount of waste generated by consuming less and making more sustainable choices.
• Refuse: Refuse to use products that are not environmentally friendly or are not necessary, such as single-use plastics or products with excessive packaging.

Correct Option: (c) Lung’s cancer
Explanation: Air pollution can contribute to lung cancer and other respiratory diseases due to the inhalation of pollutants such as particulate matter, nitrogen oxides, sulfur dioxide, and volatile organic compounds.

Correct Option: (a) Sewerage water
Explanation: Sewerage water can contain harmful pathogens that cause diseases like typhoid when ingested or come into contact with open wounds or mucous membranes.

Correct Option: (d) Polythene bag
Explanation: Polythene bags are non-biodegradable as they are made of synthetic polymers that do not break down easily in the environment.

Correct Option: (a) Oxygen
Explanation: Oxygen is not considered a greenhouse gas. Greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3), among others.

Correct Option: (b) Burning rubber
Explanation: Burning rubber, such as in the form of tire fires or the incineration of rubber products, releases harmful pollutants into the air and contributes to air pollution.

Correct Option: (b) Matter
Explanation: Matter is defined as anything that has mass and takes up space.

Correct Option: (b) Three
Explanation: There are three types of matter: solid, liquid, and gas.

Correct Option: (a) Physical
Explanation: A physical change is a change in the form or appearance of matter, but not in its chemical composition. For example, melting, freezing, and boiling are physical changes.

Correct Option: (a) Physical
Explanation: Dissolving salt in water is a physical change because it does not change the chemical composition of the salt or water.

Correct Option: (a) Reversed
Explanation: Physical states of matter (solid, liquid, gas) can be reversed through physical changes such as melting, freezing, and evaporating.

Correct Option: (a) Melting
Explanation: Melting is the process of changing a solid into a liquid by heating it until it reaches its melting point.

Correct Option: (a) Liquid
Explanation: When a solid is heated, it changes into a liquid through the process of melting.

Correct Option: (b) Freezing
Explanation: Freezing is the process of changing a liquid into a solid by cooling it until it reaches its freezing point.

Correct Option: (a) Boiling
Explanation: Boiling is the process of changing a liquid into a gas by heating it until it reaches its boiling point.

Correct Option: (c) Evaporation
Explanation: Evaporation is the process of changing a liquid into a gas by heating it until it reaches its boiling point.

Correct Option: (d) Condensation
Explanation: Condensation is the process of changing a gas into a liquid by cooling it until it reaches its condensation point.

Correct Option: (c) Evaporation
Explanation: Wet clothes dry due to the process of evaporation, where water molecules in the clothes absorb heat from the surroundings and change into water vapor, which then escapes into the air.

Correct Option: (c) Evaporation
Explanation: Evaporation is the process of changing a liquid into a gas at any temperature, as long as the liquid is exposed to air.

Correct Option: (c) Evaporation
Explanation: At high temperatures, the process of evaporation becomes more rapid because the heat energy increases the kinetic energy of the molecules, causing them to move faster and escape from the liquid.

Correct Option: (c) Evaporation
Explanation: When sweat evaporates from our skin, it absorbs heat from our body, which cools us down and gives us a sensation of coldness.

Correct Option: (a) Mixture
Explanation: A mixture is a combination of two or more substances that are not chemically combined and can be separated by physical means.

Correct Option: (a) Retain
Explanation: In a mixture, the constituent substances retain their original properties and can be separated by physical methods.

Correct Option: (c) Both (a) & (b)
Explanation: A mixture can be homogeneous (uniform composition throughout) or heterogeneous (non-uniform composition).

Correct Option: (c) Solutions
Explanation: Most homogeneous mixtures are solutions, where one substance (solvent) dissolves another substance (solute) to form a uniform mixture.

Correct Option: (a) Homogeneous
Explanation: Air is a homogeneous mixture of gases, meaning it has a uniform composition throughout.

Correct Option: (a) Homogeneous
Explanation: Metal alloys like brass, bronze, and steel are homogeneous mixtures where the metal atoms are evenly distributed throughout the mixture.

Correct Option: (b) Heterogeneous
Explanation: Heterogeneous mixtures can be separated by physical methods because their components are not evenly distributed throughout the mixture.

Correct Option: (b) Heterogeneous
Explanation: Soil is a heterogeneous mixture of organic matter, minerals, water, and air, where the components are not uniformly distributed.

Correct Option: (c) Solution
Explanation: A solution is formed when a solute (solid or liquid) is dissolved in a solvent (usually a liquid) to form a homogeneous mixture.

Correct Option: (a) Two
Explanation: Solutions have two main components: solute (the substance being dissolved) and solvent (the substance doing the dissolving).

Correct Option: (a) Solute
Explanation: The solute is the substance that dissolves in the solvent and is usually present in smaller amounts in a solution.

Correct Option: (b) Solvent
Explanation: The solvent is the substance that dissolves a solute and is usually present in larger amounts in a solution.

Correct Option: (a) Solute
Explanation: In a saltwater solution, salt is the solute, and water is the solvent.

Correct Option: (b) Solvent
Explanation: In a saltwater solution, water is the solvent, as it dissolves the salt (solute).

Correct Option: (d) All of these
Explanation: Stirring increases the surface area for contact, increasing temperature speeds up the process, and decreasing the size of particles exposes more surface area for dissolving.

Correct Option: (a) depends
Explanation: The dissolution rate of a solute depends on the size of its particles. Smaller particles dissolve faster because they have a larger surface area for contact with the solvent.

Correct Option: (c) Solutions
Explanation: Milk, tea, and soft drinks are all examples of solutions, where a solute (sugar, flavorings, etc.) is dissolved in a solvent (water).

Correct Option: (a) Dilute
Explanation: A dilute solution contains a small amount of solute relative to the amount of solvent.

Correct Option: (b) Concentrated
Explanation: A concentrated solution contains a large amount of solute relative to the amount of solvent.

Correct Option: (c) Chemical
Explanation: A chemical change involves a change in the chemical composition of a substance, leading to the formation of new substances with different properties.

Correct Option: (c) Decomposition
Explanation: Decomposition is the process where dead organisms and waste materials are broken down into simpler substances by bacteria and fungi.

Correct Option: (c) Decaying
Explanation: Decaying is the process by which bacteria and fungi break down dead bodies into simpler components.

Correct Option: (d) Flame
Explanation: A flame develops during the combustion reaction, which is a chemical reaction between a fuel and an oxidizing agent (usually oxygen) that produces heat, light, and new substances.

Correct Option: (d) Burning
Explanation: Burning is the process where a substance reacts with oxygen to produce heat, light, and new substances.

Correct Option: (a) Rusting
Explanation: Rusting is a chemical reaction between iron, oxygen, and water, leading to the formation of iron oxide (rust) on the surface of iron objects.

Correct Option: (c) Rusting
Explanation: The reaction of iron with oxygen in the presence of water or moisture leads to the formation of iron oxide, commonly known as rust.

Correct Option: (a) Rusting
Explanation: Painting iron surfaces with oil or chromium helps prevent rusting by forming a protective barrier that prevents oxygen and moisture from coming into contact with the iron surface.

Correct Option: (a) Physical
Explanation: In a physical change, no new substances are formed, and the chemical composition of the matter remains the same.

Correct Option: (b) Chemical
Explanation: In a chemical change, new substances are formed with different properties compared to the original substances.

Correct Option: (a) Physical
Explanation: Physical changes can often be reversed by changing the conditions (e.g., heating or cooling), and the original substance can be recovered.

Correct Option: (b) Chemical
Explanation: Chemical changes are usually irreversible because they result in the formation of new substances with different chemical properties.

Correct Option: (b) Chemical
Explanation: Burning of paper involves a chemical reaction between paper and oxygen, leading to the formation of new substances like carbon dioxide and water vapor.

Correct Option: (c) Chemical change
Explanation: The process of milk turning into yogurt involves the fermentation of lactose (milk sugar) by bacteria, resulting in the formation of lactic acid and the coagulation of milk proteins.

Correct Option: (a) To save from rusting
Explanation: Painting an iron gate forms a protective layer that prevents direct contact between oxygen and moisture in the air and the iron surface, thereby preventing rusting.

Correct Option: (a) To add salt in water
Explanation: Adding salt to water will not affect the dissolving of sugar in water because salt and sugar are different substances with different properties, and their solubilities in water are not affected by each other.

Correct Option: (b) Making paper boat
Explanation: Making a paper boat involves a physical change where the shape and appearance of the paper change, but no new substances are formed.

Correct Option: (c) Physical
Explanation: The expansion of metal on heating is a physical change because the substance remains the same, and no new substances are formed.

Correct Answer: (c) Sun
Explanation: Our day starts with the rising of the Sun in the morning. The Sun is the primary source of light and energy for Earth.

Correct Answer: (b) Natural
Explanation: Sun and stars are natural sources of light. Artificial sources of light include light bulbs, LED lights, and fluorescent lights.

Correct Answer: (b) Energy
Explanation: Light is a form of energy that travels in waves. It is part of the electromagnetic spectrum.

Correct Answer: (c) using sunlight
Explanation: Plants prepare their food through the process of photosynthesis, which involves using sunlight, carbon dioxide, and water to produce glucose and oxygen.

Correct Answer: (c) Light
Explanation: Light travels at the fastest speed in the universe, which is approximately 300,000 kilometers per second in a vacuum.

Correct Answer: (b) 300,000
Explanation: Light travels approximately 300,000 kilometers per second in air or vacuum.

Correct Answer: (c) Moon
Explanation: The Moon reflects light from the Sun and does not produce its own light.

Correct Answer: (b) Chemical reaction
Explanation: Fireflies and some sea fish emit light through a chemical reaction called bioluminescence.

Correct Answer: (a) Luminous
Explanation: Luminous objects emit light. Examples include the Sun, stars, and light bulbs.

Correct Answer: (b) Non-luminous
Explanation: Non-luminous objects do not emit light but reflect light from other sources. Examples include a book, a table, and the Moon.

Correct Answer: (c) 8
Explanation: The light from the Sun takes approximately 8 minutes and 20 seconds to reach the Earth.

Correct Answer: (a) 1.5
Explanation: The light reflected from the Moon takes about 1.5 seconds to reach us on Earth.

Correct Answer: (b) Reflect light from the Sun
Explanation: The Sun is the primary source of light in our solar system, emitting light and heat. The Moon reflects light from the Sun, making it visible to us on Earth. Planets also reflect light from the Sun, making them visible in the night sky.

Correct Answer: (a) Transparent
Explanation: Transparent objects allow light to pass through them completely. Examples include clear glass and water.

Correct Answer: (a) Transparent
Explanation: Transparent objects allow light to pass through them clearly, making objects on the other side visible.

Correct Answer: (c) Translucent
Explanation: Translucent objects allow light to pass through them partially, making objects on the other side somewhat visible but not completely clear.

Correct Answer: (b) Opaque
Explanation: Opaque objects do not allow light to pass through them at all. Examples include wood and metal.

Correct Answer: (b) Sailors
Explanation: Sailors used light signals, such as lanterns and flag semaphore, for communication before the invention of telephone or radio.

Correct Answer: (a) Transparent
Explanation: Air is an example of a transparent substance. It allows light to pass through it easily.

Correct Answer: (a) Straight
Explanation: Light travels in straight lines, unless it is refracted or reflected by an object or surface.

Correct Answer: (b) Non-transparent
Explanation: Shadows are formed when non-transparent objects block light.

Correct Answer: (b) Opposite
Explanation: A shadow is formed in the opposite direction of the source of light.

Correct Answer: (b) Bigger
Explanation: When an object is closer to the source of light, its shadow appears larger because the light rays diverge more, resulting in a larger shadow. As the distance between the object and the light source increases, the shadow becomes smaller.

Correct Answer: (a) Smaller
Explanation: When an object is closer to the source of light, its shadow appears larger because the light rays diverge more, resulting in a larger shadow. As the distance between the object and the light source increases, the shadow becomes smaller.

Correct Answer: (b) Reflection
Explanation: Reflection is the bouncing back of light from a non-transparent surface.

Correct Answer: (b) Sound
Explanation: A vibrating object produces sound waves, which are perceived as sound when they reach our ears.

Correct Answer: (c) Air
Explanation: Sound travels through the air and reaches our ears, allowing us to hear it.

Correct Answer: (b) Sound
Explanation: When an object vibrates, it creates sound waves that travel through the air, allowing us to hear the sound.

Correct Answer: (a) Vibration
Explanation: The buzzing sound produced by flies and mosquitoes is due to the vibration of their wings.

Correct Answer: (a) Can
Explanation: Sound can pass through solid objects, although its intensity may decrease depending on the material and thickness of the object.

Correct Option: (a) can
Explanation: Sound can travel through water, as water is a medium that allows sound waves to propagate.

Correct Option: (d) All of these
Explanation: Sound can travel through solids, liquids, and gases, but the speed and transmission properties may vary depending on the medium.

Correct Option: (b) Faster
Explanation: Sound travels faster through solid objects than through air, as the particles in solids are more closely packed and can transmit sound more efficiently.

Correct Option: (b) 5
Explanation: The speed of sound in air is approximately 343 meters per second (m/s), while the speed of sound in water is approximately 1482 m/s. Therefore, the speed of sound in water is approximately 4.32 times greater than in air.

Correct Option: (c) 15
Explanation: The speed of sound in air is approximately 343 meters per second (m/s), while the speed of sound in solids can vary greatly depending on the material. In general, the speed of sound in solids is much greater than in air, often on the order of thousands of meters per second. For example, the speed of sound in steel is approximately 6100 m/s, while in diamond it is approximately 12000 m/s. Therefore, the speed of sound in solids can be approximately 15 to 35 times greater than in air.

Correct Option: (d) Space
Explanation: Sound cannot travel through space, as space is a vacuum with no air or other medium to transmit sound waves.

Correct Option: (d) All of these
Explanation: Sound cannot pass through space because there are no particles to vibrate, no air to travel, and space is a vacuum.

Correct Option: (c) 340
Explanation: The speed of sound in air at 20°C (68°F) is approximately 343 meters per second, or about 1,235 kilometers per hour.

Correct Option: (b) 1500
Explanation: The speed of sound in water is approximately 1500 meters per second, or about 5400 kilometers per hour.

Correct Option: (d) 5000
Explanation: The speed of sound in iron is approximately 5,130 meters per second.

Correct Option: (a) Vibration
Explanation: Sound is a form of energy that travels as waves through matter, causing the particles of the medium to vibrate.

Correct Option: (c) Loudness
Explanation: The intensity of sound depends on its loudness, which is a measure of the energy of the sound waves.

Correct Option: (b) Greater
Explanation: The louder the sound, the greater its intensity, as intensity is directly proportional to the square of the amplitude of the sound waves.

Correct Option: (b) Decreases
Explanation: The intensity of sound decreases with the increase of distance from its source, as the energy of the sound waves spreads out over a larger area.

Correct Option: (a) Music
Explanation: Music is a pleasant sound that is produced by voices or instruments and is characterized by melody, rhythm, and harmony.

Correct Option: (b) Noise
Explanation: Noise is an unpleasant sound that is loud, harsh, or discordant and can be irritating or harmful to the ears.

Correct Option: (c) Astronauts
Explanation: Astronauts who landed on the moon used a wireless radio system for communication, as there is no air in space to carry sound waves.

Correct Option: (c) Along straight line
Explanation: Light travels in air in a straight line unless it is refracted or reflected by an object.

Correct Option: (c) Mirror
Explanation: A mirror reflects the maximum amount of light because it has a highly polished surface that reflects light rays in a regular and ordered manner.

Correct Option: (a) A metal wire
Explanation: The speed of sound is generally the fastest in solids, and among solids, it is often fastest in metals. This is because sound waves travel more efficiently through the closely packed atoms and molecules in a solid, compared to a liquid or gas where the particles are more spread out. In a metal wire, the sound waves can travel quickly through the closely packed atoms in the lattice structure.

Correct Option: (c) Pressure horn
Explanation: The sound of a pressure horn is called noise, as it is loud, harsh, and can be irritating or harmful to the ears.

Correct Option: (c) Sound will become fast
Explanation: When sound travels from air into water, it speeds up because the particles in water are more closely packed together than in air. This causes the sound waves to travel faster through water than through air.

Correct answer: (b) Energy
Explanation: Electricity is a form of energy that results from the movement of charged particles, such as electrons, through a conductor.

Correct answer: (a) Electric
Explanation: The term “electricity” is commonly used to refer to the flow of electric current through a conductor.

Correct answer: (c) Cables
Explanation: Electric current flows through conductors, such as wires or cables, which are made of materials that allow the flow of electrons.

Correct answer: (b) Charge
Explanation: Charge is a fundamental property of matter, along with mass and spin. Charged particles, such as protons and electrons, interact with each other through the electromagnetic force.

Correct answer: (a) Two
Explanation: There are two types of charge: positive charge, which is carried by protons, and negative charge, which is carried by electrons.

Correct answer: (c) Rubbing with air
Explanation: Clouds become charged through a process called triboelectricity or frictional charging, which occurs when different materials rub against each other and exchange electrons. In the case of clouds, water droplets and ice particles rub against each other as they move around in the atmosphere, causing them to become electrically charged. This process is also known as frictional charging.

Correct answer: (c) Spark
Explanation: When clouds with opposite charges come near each other, a spark can be produced due to the discharge of static electricity.

Correct answer: (c) Lightning
Explanation: Lightning is a natural electrical discharge that occurs between clouds or between a cloud and the ground when there is a large buildup of electrical charge in the atmosphere.

Correct answer: (c) Static electricity
Explanation: Lightning is an example of static electricity, where a buildup of charge in the atmosphere is discharged as a spark or lightning bolt.

Correct answer: (b) Negative
Explanation: When a plastic comb is rubbed against dry hair, electrons are transferred from the hair to the comb, leaving the hair with a positive charge and the comb with a negative charge.

Correct answer: (b) Negative
Explanation: When a balloon is rubbed with a woolen cloth, electrons are transferred from the woolen cloth to the surface of the balloon. Thus the balloon has a negative charge and the cloth has a positive charge.

Correct answer: (b) Repeal
Explanation: Similar charges, such as two positive charges or two negative charges, repel each other due to the electromagnetic force.

Correct answer: (a) Attract
Explanation: Opposite charges, such as a positive charge and a negative charge, attract each other due to the electromagnetic force.

Correct answer: (b) Atom
Explanation: An atom is the smallest unit of matter that retains the properties of an element.

Correct answer: (b) Atom
Explanation: An atom contains electrons, protons, and neutrons. Electrons and protons are the smallest charged particles.

Correct answer: (c) Neutral
Explanation: When an atom has an equal number of protons and electrons, it is electrically neutral.

Correct answer: (c) No
Explanation: A neutral atom has the same number of positively charged protons and negatively charged electrons. Since the number of protons and electrons are the same in a neutral atom, the overall charge of a neutral atom is zero.

Correct answer: (a) Positive
Explanation: A proton is a positively charged subatomic particle found in the nucleus of an atom.

Correct answer: (b) Negative
Explanation: An electron is a negatively charged subatomic particle found outside the nucleus of an atom.

Correct answer: (b) Equal
Explanation: In a neutral atom, the number of protons is equal to the number of electrons.

Correct answer: (c) Neutral
Explanation: An atom as a whole is neutral because it has equal numbers of protons (positively charged) and electrons (negatively charged), which balance each other out.

Correct answer: (a) Positive
Explanation: When a material loses electrons, it becomes positively charged because it has more protons than electrons.

Correct answer: (b) Negative
Explanation: When a material gains excess electrons, it becomes negatively charged because it has more electrons than protons.

Correct answer: (a) Positive
Explanation: When a material has a deficiency of electrons, it means it has more protons than electrons, resulting in a positive charge.

Correct answer: (b) Electric current
Explanation: Electric current is the flow of electric charge. It is typically measured in amperes (A).

Correct answer: (c) Switch
Explanation: A switch is a device used to open or close an electric circuit, thereby controlling the flow of electric current.

Correct answer: (c) Path
Explanation: An electric circuit is the path along which electric current flows. It typically includes a source of electricity (such as a battery), conductors (such as wires), and various components (such as resistors, capacitors, and switches).

Correct answer: (d) All of these
Explanation: The components of an electric circuit can include a wide range of devices and elements, such as bulbs (light bulbs), batteries or cells, switches, resistors, capacitors, inductors, transformers, diodes, transistors, integrated circuits, and more.

Correct answer: (a) Electric
Explanation: A battery is a device that converts chemical energy into electrical energy, providing a source of electric current.

Correct answer: (b) Closed
Explanation: An electric circuit can be either open or closed. In a closed circuit, the path for the flow of electric current is complete, allowing the current to flow. In an open circuit, the path is broken, preventing the flow of current.

Correct answer: (b) Closed
Explanation: When the switch is turned ON, it closes the circuit, allowing the flow of electric current through it. This is known as a closed circuit.

Correct answer: (a) Open
Explanation: When the switch is turned OFF, it opens the circuit, breaking the path for the flow of electric current. This is known as an open circuit.

Correct answer: (a) Open
Explanation: When the current stops flowing through the circuit, it is called an open circuit, as the path for the flow of electric current is broken.

Correct answer: (b) Closed
Explanation: When the current starts flowing through the circuit, it is called a closed circuit, as the path for the flow of electric current is complete.

Correct answer: (a) Conductors
Explanation: Conductors are materials that allow electric current to pass through them easily. Metals like copper, silver, and iron are good conductors.

Correct answer: (b) Insulators
Explanation: Insulators are materials that do not allow electric current to pass through them easily. Non-metals like wood, rubber, and plastic are good insulators.

Correct answer: (d) All of these
Explanation: Iron, copper, and other metallic objects are all conductors of electricity.

Correct answer: (d) All of these
Explanation: Wood, rubber, and plastic are all insulators of electricity.

Correct answer: (c) Diamond
Explanation: Diamond is an excellent insulator of electricity but a good conductor of heat.

Correct answer: (b) Safe
Explanation: A fuse is used in a circuit to protect against excessive current flow, which could lead to harm or damage. It is designed to melt and break the circuit if the current exceeds a certain safe level.

Correct answer: (c) Fuse
Explanation: A fuse is a thin wire that is designed to melt and break the circuit if the current exceeds a certain safe level, protecting electrical appliances from damage.

Correct answer: (b) break
Explanation: When excessive current passes through the fuse, it causes the fuse to melt and break the circuit, stopping the flow of current to prevent damage.

Correct answer: (b) Stop
Explanation: When excessive current passes through the fuse, it will blow immediately, causing the circuit to break and stopping the flow of current.

Correct answer: (c) Fuse
Explanation: Circuit breakers are used instead of fuses in modern electrical circuits because they can be reset after tripping, while fuses need to be replaced.

Correct answer: (b) Stop
Explanation: The instant tripping of the circuit breaker stops the current flow, preventing any damage to the electrical appliances or the circuit itself.

Correct answer: (c) Magnet
Explanation: A magnet is a piece of metal that has the ability to attract certain materials, such as iron, nickel, and cobalt.

Correct answer: (c) Attracted
Explanation: Materials that are attracted by a magnet are called magnetic materials, such as iron, nickel, and cobalt.

Correct answer: (d) All of these
Explanation: All of the listed materials, iron, nickel, and cobalt, are examples of magnetic materials.

Correct answer: (d) Not attracted
Explanation: Materials that are not attracted by a magnet are called non-magnetic materials, such as wood, glass, plastic, and rubber.

Correct answer: (d) All of these
Explanation: All of the listed materials, copper, wood, glass, plastic, and rubber, are examples of non-magnetic materials. They do not have magnetic properties and are not attracted to magnets.

Correct answer: (a) Magnetic
Explanation: Magnetic materials can be magnetized to make magnets, while non-magnetic materials cannot.

Correct answer: (b) Greeks
Explanation: The Greeks discovered natural magnets over 2000 years ago.

Correct answer: (a) Two
Explanation: A magnet has two poles: a north pole and a south pole.

Correct answer: (c) North-south
Explanation: A freely suspended magnet always points in the north-south direction, aligning itself with the Earth’s magnetic field.

Correct answer: (a) North pole
Explanation: The end of a bar magnet that points towards the north is called its north pole.

Correct answer: (b) South pole
Explanation: The end of a bar magnet that points towards the south is called its south pole.

Correct answer: (c) Ends
Explanation: The ends of a magnet are called its magnetic poles.

Correct answer: (a) Red
Explanation: In a magnet, usually, red color is coated to show the North Pole, while the South Pole is usually indicated by blue.

Correct answer: (b) Blue
Explanation: In a magnet, usually, blue color is coated to show the South Pole, while the North Pole is usually indicated by red.

Correct answer: (d) Strongest
Explanation: The magnetic force of the magnet is the strongest at the magnetic poles.

Correct answer: (b) Repel
Explanation: Like magnetic poles repel each other, meaning that two north poles or two south poles will push away from each other.

Correct answer: (a) Attract
Explanation: Unlike (opposite) magnetic poles attract each other, meaning that a north pole and a south pole will be drawn toward each other.

Correct answer: (d) Bar magnet
Explanation: The Earth behaves like a huge bar magnet because it has a magnetic field similar to that of a bar magnet, with north and south poles. This magnetic field extends from the Earth’s interior into space and influences the behavior of magnetic materials and compass needles.

Correct answer: (c) Magnetic compass
Explanation: A magnetic compass is used to find the direction at any place by aligning itself with the Earth’s magnetic field.

Correct answer: (a) magnetic
Explanation: A magnetic chip is built in a credit card of a bank, used for storing data and enabling transactions.

Correct answer: (c) read
Explanation: The ATM machine is programmed to read the data of the user present in the chip, such as account information and transaction details.

Correct answer: (b) Three
Explanation: There are three main types of magnets: Temporary, permanent, and electromagnet.

Correct answer: (a) Temporary magnet
Explanation: Some iron and iron alloys act as temporary magnets.

Correct answer: (b) Permanent magnet
Explanation: A magnet made by steel is a permanent magnet, meaning it retains its magnetism for a long time.

Correct answer: (c) Electromagnet
Explanation: When an iron nail or rod is placed in a current-carrying coil, it becomes a magnet due to the magnetic field generated by the electric current. This is known as an electromagnet.

Correct answer: (b) Temporary
Explanation: An electromagnet is a temporary magnet that only produces a magnetic field when an electric current is flowing through it.

Correct answer: (c) Switch
Explanation: A switch is used to control the flow of electric current in an electric circuit. When the switch is on, current flows, and when it’s off, current does not flow.

Correct answer: (a) Steel paper clip
Explanation: Steel is a good conductor of electricity, so current can easily pass through a steel paper clip.

Correct answer: (b) 2
Explanation: A ring-shaped magnet has two poles: a north pole and a south pole.

Correct answer: (b) North-south direction
Explanation: A freely suspended bar magnet aligns itself along the north-south direction due to the Earth’s magnetic field.

Correct answer: (b) North pole repels north pole
Explanation: According to the law of magnetism, like poles repel each other, so the north pole of a magnet repels another north pole.

Correct answer: (a) Temporary magnet
Explanation: Iron is commonly used to make temporary magnets, which become magnetic when exposed to a magnetic field but lose their magnetism once the field is removed.

Correct answer: (b) Permanent magnet
Explanation: Steel is commonly used to make permanent magnets because it retains its magnetism over time. Steel has a good ability to hold a magnetic charge, making it ideal for permanent magnets.

Correct answer: (c) Electromagnet
Explanation: When an iron nail or rod is placed in a current-carrying coil, it becomes a magnet due to the magnetic field generated by the electric current. This is known as an electromagnet.

Correct answer: (b) Temporary
Explanation: An electromagnet is a temporary magnet because it only becomes magnetic when electric current flows through the coil. Once the current is stopped, it does not remain magnetic.

Correct answer: (c) Switch
Explanation: The flow of current in an electric circuit is controlled by a switch, which can be turned on or off to allow or stop the flow of electricity.

Correct answer: (a) Steel paper clip
Explanation: Current can easily pass through conductive materials like metals, such as a steel paper clip.

Correct answer: (b) 2
Explanation: A ring-shaped magnet typically has two poles: a north pole and a south pole.

Correct answer: (b) North-south direction
Explanation: A freely suspended bar magnet always aligns itself along the north-south direction due to the Earth’s magnetic field.

Correct answer: (b) North pole repels north pole
Explanation: Like magnetic poles repel each other, meaning that two north poles or two south poles will push away from each other.

Correct answer: (d) Earth
Explanation: Earth is the only planet in our solar system where conditions are suitable for the existence of life as we know it.

Correct answer: (b) 12800 km
Explanation: The diameter of the Earth is approximately 12,800 kilometers.

Correct answer: (c) 150
Explanation: The average distance of the Earth from the Sun is approximately 150 million kilometers.

Correct answer: (b) Three
Explanation: The Earth is composed of three main layers: the crust, the mantle, and the core.

Correct answer: (a) Crust
Explanation: The outermost layer of the Earth is called the crust.

Correct answer: (a) Crust
Explanation: We live on the Earth’s crust, which is the outermost layer of the planet.

Correct answer: (a) Crust
Explanation: The Earth’s crust contains various geographical features such as mountains, oceans, rivers, and human settlements.

Correct answer: (a) Crust
Explanation: The Earth’s crust is made up of solid rocks and minerals.

Correct answer: (b) 5 to 70 km
Explanation: The average thickness of the Earth’s crust is approximately 5 to 70 kilometers.

Correct answer: (a) 5
Explanation: Beneath the oceans, the thickness of the Earth’s crust is relatively thin, approximately 5 kilometers.

Correct answer: (b) Mantle
Explanation: The layer of the Earth under the crust is called the mantle.

Correct answer: (b) Mantle
Explanation: The mantle is the largest part of the Earth by volume.

Correct answer: (b) 3900 km
Explanation: The thickness of the mantle is about 3900 km.

Correct answer: (b) Mantle
Explanation: The mantle is extremely hot and has the consistency of a highly viscous fluid.

Correct answer: (b) Mantle
Explanation: The hot fluid in the mantle of the Earth comes out of the Earth’s surface in the form of lava during volcanic eruptions.

Correct answer: (c) Core
Explanation: The central part of the Earth is called the core.

Correct answer: (c) Core
Explanation: The hottest part of the Earth is its core, where temperatures can reach up to 7000°C.

Correct answer: (b) 5000
Explanation: The temperature of the core is about 5000°C.

Correct answer: (a) Two
Explanation: The Earth’s core consists of two parts: the outer core and the inner core or internal and external core.

Correct answer: (a) Solid
Explanation: The inner core of the Earth is believed to be solid due to intense pressure, despite its extremely high temperature.

Correct answer: (c) Molten fluid
Explanation: The external core of the Earth is in the form of a thick black molten fluid which contains elements like iron and nickel.

Correct answer: (a) Internal
Explanation: The internal core of the Earth contains elements like iron and nickel.

Correct answer: (c) Rock
Explanation: The soil on the Earth’s surface is formed by a very slow process of rock weathering.

Correct answer: (a) 5
Explanation: The soil on the Earth’s surface is formed by a very slow process of rock weathering. It takes about 1000 years to make only a 5 cm thick layer of soil.

Correct answer: (a) 16%
Explanation: The volume of the internal core of the Earth is approximately 16% of the total volume of the Earth.

Correct answer: (b) 33%
Explanation: The weight of the internal core of the Earth is approximately 33% of the total of the Earth.

Correct answer: (b) 70%
Explanation: Approximately 70% of the Earth’s surface is covered by water.

Correct answer: (c) 2%
Explanation: About 2% of the water on Earth’s surface is frozen in the form of ice caps and glaciers.

Correct answer: (d) 97%
Explanation: About 97% of the water in the oceans is salty.

Correct answer: (a) 1%
Explanation: The fresh water available to mankind is approximately 1% of the total water on the Earth’s surface.

Correct answer: (b) Three
Explanation: Water on Earth is found in three states: solid (ice), liquid (water), and gas (water vapor).

Correct answer: (d) All of these
Explanation: On Earth, water is found in all three states: solid (ice), liquid (water), and gas (water vapor).

Correct answer: (d) Fresh
Explanation: Glaciers, rain, lakes, springs, and underground water are sources of fresh water, which is not salty, polluted, or dirty.

Correct answer: (c) Water
Explanation: Water undergoes a big cyclic process called the water cycle, which includes processes like evaporation, condensation, precipitation, and transpiration.

Correct answer: (b) Sea
Explanation: The evaporated water from water bodies, such as oceans, rivers, and lakes, eventually condenses in the atmosphere to form clouds. These clouds can then release precipitation in the form of rain or snow, and this water returns to the Earth’s surface, including back to the seas and other bodies of water.

Correct answer: (c) Rocks
Explanation: The major part of the Earth’s crust is made up of rocks.

Correct answer: (c) Weathering
Explanation: Weathering is the process of breaking down rocks by exposure to sunlight, rain, wind, and other environmental factors.

Correct answer: (a) Slow
Explanation: Weathering is generally a slow process that occurs over long periods of time.

Correct answer: (c) Soil
Explanation: The weathering process converts rocks into small particles, leading to the formation of soil on the Earth’s surface.

Correct answer: (c) Humus
Explanation: Humus is the organic matter produced by the decay of vegetables, plants, and dead animals. It is an essential component of soil and contributes to its fertility.

Correct answer: (c) Fertile
Explanation: Humans retain moisture in the soil through irrigation and other methods, making the soil more fertile and suitable for agriculture.

Correct answer: (c) Humus
Explanation: The top layer of soil, known as the topsoil, contains a sufficient amount of humus, which is crucial for the growth of plants.

Correct answer: (b) Clay
Explanation: Below the topsoil, there is a layer of subsoil, which contains a higher concentration of clay particles.

Correct answer: (d) Gravel
Explanation: The lowest layer of soil typically consists of gravel, which is composed of small rock fragments. These rock fragments are larger than those found in layers above, such as clay or silt. Gravel provides a coarse texture to the soil and forms the base layer of the soil profile.

Correct answer: (b) Three
Explanation: There are generally three types of soil: clay, sand, and silt.

Correct answer: (b) Small
Explanation: Clay particles are very small in size, which is why clay soil has a fine texture.

Correct answer: (a) Clay
Explanation: Clay soil is soft, sticky, and brownish in color, with a fine texture.

Correct answer: (a) Clay
Explanation: Clay soil can hold more water than sand or silt soil because of its finer texture and smaller particle size.

Correct answer: (a) Clay
Explanation: Clay soil can become very hard when dry, making it difficult to cultivate or till.

Correct answer: (a) Clay
Explanation: Clay soil is used to make bricks and pottery due to its ability to be molded and shaped when wet and then harden when dried.

Correct answer: (b) Sand
Explanation: Sand soil feels gritty and coarse due to its larger particle size.

Correct answer: (b) Sand
Explanation: Sand soil consists mostly of silica grains, which give it its gritty texture.

Correct answer: (b) Sand
Explanation: Sand soil is often found on coastal areas or river beds, where it is carried by water and deposited.

Correct answer: (d) All of these
Explanation: Silt soil is a mixture of sand, clay, and humus, and it has a smooth, silky texture.

Correct answer: (c) Silt
Explanation: Silt soil is good for cultivation because it has good water retention, good drainage, and a smooth texture that is easy to work with.

Correct answer: (c) Silt
Explanation: Silt soil has a smooth and silky texture due to its fine particle size.

Correct answer: (c) Silt
Explanation: Silt soil has good water retention and provides water and minerals to plants.

Correct answer: (a) Clay
Explanation: Clay soil is useful for making pottery and bricks due to its ability to be molded and shaped when wet and then harden when dried. Sand is useful to make glass and silt is good for cultivation.

Correct answer: (b) Home
Explanation: Soil is the home of many living organisms like earthworms, insects, beetles, rats, rabbits, and many others, providing them with shelter and nutrients.

Correct answer: (c) Fertility
Explanation: Bacteria and other microorganisms in the soil break down the wastes of living animals and dead plants, converting them into useful nutrients. This process increases the fertility of the soil, making it more suitable for plant growth.

Correct answer: (c) Crust
Explanation: The outer layer of the Earth, which is relatively thin compared to the other layers, is called the crust. It is composed of solid rock and is where all life exists.

Correct answer: (c) Sand, silt, and clay
Explanation: The main types of soil are sand, silt, and clay, which are defined by the size of their particles.

Correct answer: (b) Silty
Explanation: Silty soil is good for the growth of plants because it retains water well and has good drainage.

Correct answer: (a) Making soil soft and airy
Explanation: Living organisms in the soil, such as earthworms, bacteria, and fungi, play a vital role in making the soil soft and airy by breaking down organic matter and creating tunnels.

Correct answer: (a) About 1%
Explanation: About 97% of the Earth’s water is in the form of saltwater in oceans and seas. Only about 1% of the Earth’s water is fresh water, and most of that is locked up in ice caps and glaciers, making it inaccessible.

Correct answer: (b) The decayed matter
Explanation: The decayed matter in natural manure, also known as organic matter or humus, is important because it provides nutrients to plants and helps improve soil structure and water retention.

Correct answer: (b) Heavenly
Explanation: Heavenly bodies refer to celestial objects such as galaxies, stars, planets, moons, comets, asteroids, and other objects found in outer space.

Correct answer: (d) Universe
Explanation: The universe encompasses all of space and time, including all of the celestial bodies such as galaxies, stars, planets, moons, comets, and asteroids.

Correct answer: (c) Rocket
Explanation: Rockets are the only vehicles that can carry humans and cargo into space, and they have made space exploration possible.

Correct answer: (c) October 4, 1957
Explanation: The space age began on October 4, 1957, when the Soviet Union successfully launched Sputnik 1, the first artificial satellite, into Earth’s orbit.

Correct answer: (d) National Aeronautics and Space Administration
Explanation: NASA, the National Aeronautics and Space Administration, is the United States government agency responsible for space exploration, scientific discovery, and aeronautics research.

Correct answer: (c) American
Explanation: NASA is an American agency, part of the United States government, responsible for the nation’s civilian space program and for aeronautics and aerospace research.

Correct answer: (c) NASA
Explanation: NASA is responsible for space exploration and aviation research in the United States.

Correct answer: (b) 20th July
Explanation: On July 20, 1969, Neil Armstrong became the first human to set foot on the moon during the Apollo 11 mission.

Correct answer: (d) International Space Station
Explanation: NASA has played a key role in the establishment and operation of the International Space Station (ISS), which serves as a laboratory for scientific research and international cooperation in space.

Correct answer: (d) International Space Station
Explanation: The International Space Station (ISS) is a large space station in low Earth orbit that serves as a home and laboratory for astronauts from multiple countries.

Correct answer: (a) Russian
Explanation: MIR was a space station operated by the Soviet Union and later by Russia. It was the first modular space station and the largest artificial satellite in orbit at the time of its operation.

Correct answer: (b) 300 km
Explanation: The MIR space station orbited the Earth for approximately 15 years at an altitude of around 300 kilometers.

Correct answer: (b) greater
Explanation: The International Space Station (ISS) is larger than a football field. It has a total pressurized volume of 388 cubic meters.

Correct answer: (d) All of these
Explanation: The ISS is a joint project of multiple countries, including Russia, Japan, Canada, and several European countries.

Correct answer: (c) 400 km
Explanation: The International Space Station (ISS) has been orbiting the Earth at an average altitude of approximately 400 kilometers for the last 20 years.

Correct answer: (c) 90 minutes
Explanation: The ISS completes one full orbit around the Earth approximately every 90 minutes.

Correct answer: (b) Soviet Union
Explanation: The Soviet Union launched Sputnik 2 into space on November 3, 1957. It was the second artificial satellite to orbit Earth, after Sputnik 1.

Correct answer: (c) Dog
Explanation: Sputnik 2, launched by the Soviet Union, carried a dog named Laika. Laika was the first living animal to orbit the Earth.

Correct answer: (c) Satellite
Explanation: A satellite is an object that orbits a larger object, such as a planet or a star, due to the force of gravity.

Correct answer: (b) Earth
Explanation: The Moon is a natural satellite of Earth, orbiting our planet at an average distance of about 384,400 kilometers.

Correct answer: (a) 2
Explanation: Mars has two moons, Phobos and Deimos.

Correct answer: (a) 79
Explanation: Jupiter has a total of 79 known moons, with the largest being Ganymede, Callisto, Io, and Europa.

Correct answer: (b) 82
Explanation: Saturn has a total of 82 known moons, with the largest being Titan, Rhea, Iapetus, and Dione.

Correct answer: (c) 27
Explanation: Uranus has a total of 27 known moons, with the largest being Titania, Oberon, Umbriel, Ariel, and Miranda.

Correct answer: (d) 14
Explanation: Neptune has a total of 14 known moons, with the largest being Triton and Nereid.

Correct answer: (c) 1
Explanation: Earth has one natural satellite, which is the Moon.

Correct answer: (d) Venus
Explanation: Venus is often called the “morning star” or the “evening star” because it is the brightest object in the sky just before sunrise or just after sunset.

Correct answer: (d) Venus
Explanation: Venus is often called the “morning star” or the “evening star” because it is the brightest object in the sky just before sunrise or just after sunset.

Correct answer: (b) West to east
Explanation: The Earth rotates on its axis from west to east, which is why the Sun, Moon, and stars appear to move from east to west across the sky.

Correct answer: (a) East to west
Explanation: Because the Earth rotates from west to east, celestial objects like the Sun, Moon, and stars appear to move from east to west across the sky.

Correct answer: (c) Artificial satellites
Explanation: The objects made by humans to orbit the Earth continuously are called artificial satellites. They serve various purposes, such as communication, weather monitoring, and research, and differ from spaceships or rockets that travel into and through space but do not stay in Earth’s orbit.

Correct answer: (b) Artificial
Explanation: Artificial satellites are man-made objects that are launched into space and orbit around the Earth. They are sent into space by rockets and are given the right speed to maintain their height and orbit.

Correct answer: (b) Slower
Explanation: The higher the satellite is, the slower its speed. This is because the force of gravity decreases with distance from the Earth, so satellites at higher altitudes experience less gravitational force and need to travel at slower speeds to maintain their orbits.

Correct answer: (a) Longer
Explanation: The higher the satellite, the longer it takes to complete one orbit. This is because the force of gravity decreases with distance from the Earth, so satellites at higher altitudes have to travel a greater distance in their orbits.

Correct answer: (c) Radio signals
Explanation: The Hubble Space Telescope uses radio signals to communicate with Earth. These signals are sent from the telescope to a ground station on Earth, where they are received and processed.

Correct answer: (b) Artificial satellite
Explanation: Artificial satellites are used to transmit radio, TV, and internet signals to different parts of the world. These satellites are positioned in geostationary orbits above the equator, allowing them to cover a large area of the Earth’s surface.

Correct answer: (a) By using GPS satellites
Explanation: The Global Positioning System (GPS) is a network of satellites that orbit the Earth and provide precise location and time information to GPS receivers on the ground. By using signals from multiple satellites, GPS receivers can determine their exact position anywhere in the world.

Correct answer: (a) Geo stationary
Explanation: Geostationary satellites are satellites that orbit the Earth at the same speed as the Earth’s rotation, so they appear to be stationary relative to a fixed point on the Earth’s surface. They are positioned in geostationary orbits above the equator.

Correct answer: (d) 36000 km
Explanation: Geostationary satellites orbit at a height of about 36,000 km above the Earth’s surface and are positioned directly above the equator.

Correct answer: (a) Geo stationary
Explanation: Geostationary satellites are commonly used for communication purposes, including transmitting TV signals across the world. They are also used for weather monitoring, navigation, and other applications.

Correct answer: (d) 1470 km
Explanation: The Earth rotates about its axis at a speed of approximately 1470 kilometers per hour over the equator. This speed is highest at the equator and decreases towards the poles.

Correct answer: (a) Geo stationary
Explanation: Geostationary satellites are positioned in orbit around the Earth at a fixed point above the equator. Due to their fixed position relative to the Earth’s rotation, they appear stationary from the ground. Three geostationary satellites strategically positioned around the equator can provide global coverage for the transmission of radio and TV programs.

Correct answer: (b) Polar Orbiting
Explanation: Polar orbiting satellites are used for weather information. These satellites orbit the Earth from pole to pole, providing global coverage and collecting data used for weather forecasting and monitoring.

Correct answer: (c) Communication
Explanation: Communication satellites are used to transmit signals of radio, TV, and mobile phones from one place to another. These satellites are positioned in geostationary or other orbits to provide coverage over specific regions.

Correct answer: (d) Remote sensing
Explanation: Remote sensing is the study of the Earth from orbiting satellites. It involves collecting and analyzing data about the Earth’s surface, atmosphere, and oceans using sensors and instruments on satellites.

Correct answer: (d) Global Positioning System
Explanation: GPS stands for Global Positioning System. It is a network of satellites that orbit the Earth and provide precise location and time information to GPS receivers on the ground.

Correct answer: (b) To accurately determine the position of objects on Earth
Explanation: The primary function of the Global Positioning System (GPS) is to accurately determine the position of objects on Earth. It uses signals from multiple satellites to calculate the exact location and time of a GPS receiver.

Correct answer: (a) 10
Explanation: Through a cell phone, we can find the position on Earth with an accuracy of about 10 meters. This is possible because cell phones use GPS signals from multiple satellites to determine their location.

Correct answer: (a) October 4, 1957
Explanation: The Soviet Union launched the first ever artificial satellite, Sputnik 1, on October 4, 1957. This marked the beginning of the space age and the start of the space race between the United States and the Soviet Union.

Correct answer: (b) January 31, 1958
Explanation: The United States launched Explorer 1 on January 31, 1958, to explore the Van Allen radiation belt. Explorer 1 was the first satellite launched by the United States.

Correct answer: (c) April 12, 1961
Explanation: Soviet Cosmonaut Yuri Gagarin became the first human to enter space and return safely on April 12, 1961. This historic flight made him an international hero and a symbol of Soviet space achievements.

Correct answer: (d) July 20, 1969
Explanation: Neil Armstrong became the first man to walk on the moon during the Apollo 11 mission on July 20, 1969. He famously said, “That’s one small step for [a] man, one giant leap for mankind,” as he stepped onto the lunar surface.

Correct answer: (a) March 1994
Explanation: The Global Positioning System (GPS) was completed on March 1994, when the last of the 24 satellites required for global coverage was launched. GPS provides accurate positioning and timing information to users around the world.

Correct answer: (b) November 20, 1998
Explanation: The first piece of the International Space Station (ISS), the Russian module Zarya, was launched on November 20, 1998. The ISS is a joint project involving multiple countries, and it serves as a laboratory for scientific research in space.

Correct answer: (c) August 6, 2012
Explanation: The robotic rover “Curiosity” was launched on November 26, 2011, and it landed on Mars on August 6, 2012. Curiosity’s mission is to explore the environment of Mars and search for signs of past or present life.

Correct answer: (b) 1958
Explanation: The Van Allen Radiation Belts were discovered in 1958 by the Explorer 1 satellite, which was the first satellite launched by the United States. The belts are regions of intense radiation surrounding the Earth, and they were named after their discoverer, James Van Allen.

Correct answer: (d) Different heavenly bodies
Explanation: The countless shining lights seen at night on the sky include not only stars but also other celestial objects such as planets, moons, asteroids, comets, and galaxies. So, option (d) Different heavenly bodies is more comprehensive and accurate.

Correct answer: (a) One day
Explanation: A geostationary satellite takes approximately one day (24 hours) to complete one orbit around the Earth. This is because the satellite is in a geostationary orbit, which means it orbits the Earth at the same rate that the Earth rotates on its axis.

Correct answer: (b) Neil Armstrong
Explanation: Neil Armstrong was the first man to step on the moon during the Apollo 11 mission on July 20, 1969. His famous words, “That’s one small step for [a] man, one giant leap for mankind,” were broadcast live around the world.

Correct answer: (c) GPS
Explanation: The system that locates the position of an object on the Earth’s surface is the Global Positioning System (GPS). GPS is a network of satellites that orbit the Earth and provide precise location and time information to GPS receivers on the ground.

Correct answer: (b) 1957
Explanation: The first artificial satellite, Sputnik 1, was sent into space by the Soviet Union on October 4, 1957. This historic event marked the beginning of the space age and the start of the space race between the United States and the Soviet Union.