All questions of Animals & Plants for CTET & State TET Exam

Features of Desert Plants
Desert plants have adapted uniquely to survive in harsh environments characterized by extreme temperatures and limited water availability. Let's analyze the given statements:
Statement A: Leaves of some plants take the shape of spines.
- This statement is true.
- Many desert plants, like cacti, have modified their leaves into spines to minimize water loss through transpiration.
- Spines also provide protection from herbivores.
Statement B: Photosynthesis in cactus plant is usually carried out by leaves.
- This statement is false.
- In cacti, the leaves are reduced to spines, and photosynthesis is primarily conducted by the stems, which are green and capable of photosynthesis.
- This adaptation helps the plant conserve water while still performing vital functions.
Statement C: Roots of most desert plants go very deep into the soil for absorbing water.
- This statement is true.
- Many desert plants have extensive root systems that can reach deep into the ground to access moisture that is unavailable to surface-level plants.
- Some plants also have shallow roots that spread widely to capture rainwater quickly when it does occur.
Conclusion
Given the analysis, the correct answer is option 'C' because:
- Statements A and C are true, while statement B is false.
- Therefore, the option that includes both true statements (A and C) is the right choice.
Understanding these adaptations is crucial for appreciating how desert flora has evolved to thrive in extreme conditions.

Explanation:

Group Living Insects with Role Allocation:
- Wasps: Wasps live in colonies with specific roles allocated to different members such as queens, workers, and drones.
- Termites: Termites live in large colonies with a caste system that includes workers, soldiers, and the queen.
- Ants: Ants also live in colonies with clearly defined roles for worker ants, soldier ants, and the queen.

Explanation of Incorrect Options:
- Option A: Honeybees and ants are correct choices, but spiders do not typically live in groups with specific role allocation.
- Option C: Ants fit the criteria, but mosquitoes and spiders do not exhibit this behavior.
- Option D: Honeybees and termites have specific role allocation, but houseflies do not live in groups with specific roles.

Conclusion:
Among the choices given, option B (Wasps, Termites, Ants) is the correct answer as all three insects live in groups with specific role allocation within their colonies.

Assertion (A): Decomposers and Their Role
Decomposers are essential organisms in ecosystems that play a critical role in nutrient cycling. They break down dead organic material, such as fallen leaves, dead animals, and other organic waste.
- Enrichment of Soil:
- Through decomposition, nutrients like nitrogen, phosphorus, and potassium are released back into the soil.
- This process enhances soil fertility, allowing plants to grow better.
Reason (R): Vultures as Decomposers
Vultures are scavengers that feed on dead animals, but they are not classified as traditional decomposers.
- Feeding Behavior:
- Vultures consume carrion (dead animals), helping to clean the environment.
- However, they do not break down organic material at a microscopic level.
- Role of True Decomposers:
- True decomposers, such as fungi and bacteria, perform the chemical breakdown of organic matter.
- They facilitate the recycling of nutrients in the ecosystem.
Conclusion: Understanding the Relationship
- Both (A) and (R) are true statements.
- However, (R) does not correctly explain (A) because vultures do not enrich the soil directly; they merely consume dead animals.
Thus, the correct answer is option 'B': Both (A) and (R) are true, but (R) is not the correct explanation of (A).

Scavengers feed on dead animals for survival. They help in cleaning the environment by removing decaying bodies. Therefore, option C is correct.

Plant Cell Wall Components:
Cell walls in plant cells are composed of various components that provide structural support and protection to the cell. Two of the main components found in the plant cell wall are cellulose and hemicellulose.

Cellulose:
- Cellulose is a long chain polymer of glucose molecules.
- It is a major component of the plant cell wall, providing strength and rigidity.
- Cellulose fibers form a network that gives the cell wall its structural integrity.
- Cellulose is synthesized by enzyme complexes called cellulose synthases, which are embedded in the cell membrane.

Hemicellulose:
- Hemicellulose is a complex carbohydrate that consists of various sugar molecules.
- It plays a role in cross-linking cellulose fibers in the cell wall, contributing to its overall strength.
- Hemicellulose also helps in water retention and provides flexibility to the cell wall.
- Different types of hemicelluloses are found in plant cell walls, such as xylans, mannans, and glucans.

Conclusion:
Both cellulose and hemicellulose are essential components of the plant cell wall, working together to provide structural support, protection, and flexibility to plant cells. These components are crucial for the overall function and integrity of plant cells.

Feathers of Birds
Feathers of birds are not just for aesthetic purposes, they serve several important functions for the birds.

Help Them to Fly
One of the primary functions of bird feathers is to help them fly. The shape and structure of feathers are essential for providing lift and enabling birds to soar through the air.

Keep Them Warm
Bird feathers also serve as insulation, helping to regulate the bird's body temperature. The downy feathers close to the bird's body trap air and create a layer of warmth, keeping the bird comfortable in various weather conditions.

Keep Them Waterproof
Another important function of bird feathers is to keep the birds dry. Many birds have specialized oil glands that they use to preen their feathers, which helps to waterproof them and prevent water from seeping in.

Conclusion
In conclusion, bird feathers play a crucial role in the survival and well-being of birds. They not only enable birds to fly, but also keep them warm, dry, and comfortable in their environment.

Mycorrhizal fungi form a mutualistic association with plant roots, enhancing nutrient absorption, particularly phosphorus.

Understanding the Correct Answer: Silkworm
Silkworms, specifically the larvae of the silk moth (Bombyx mori), possess a remarkable ability to locate potential mates over considerable distances using their sense of smell. This capability is primarily due to the following factors:
1. Pheromone Detection
- Silkworm females release specific chemical signals known as pheromones into the air.
- Males can detect these pheromones from several kilometers away using their highly sensitive antennae.
- This adaptation is crucial for reproduction, as it allows males to find females even in dense environments.
2. Sensory Adaptations
- The antennae of silkworm males are equipped with specialized sensory receptors.
- These receptors respond to the chemical composition of the pheromones, enabling precise detection.
- This biological design enhances their ability to locate a mate, ensuring the continuation of their species.
3. Importance in Reproduction
- The ability to find females from long distances increases mating opportunities.
- Successful mating is essential for the lifecycle of silkworms, as they are cultivated for silk production.
- Farmers and breeders often rely on this natural behavior to optimize breeding programs.
Conclusion
In conclusion, silkworms are uniquely adapted to find their female counterparts using chemical cues. This distinguishes them from earthworms, flatworms, and tapeworms, which do not possess the same level of olfactory capabilities for mate detection. Understanding these biological traits is essential in the context of their ecological and economic significance.

- Nocturnal birds: Nocturnal birds are birds that are active during the night. They have specially adapted eyes that allow them to see well in low light conditions. This enables them to hunt for food and navigate in the dark.
- Black and white vision: Nocturnal birds typically have monochromatic vision, which means they see in black and white. This type of vision helps them to detect movement and contrast in low light situations.
- Fast flying: Nocturnal birds, such as owls and nightjars, are known for their fast and agile flight. This allows them to quickly catch their prey in the darkness.
- Adapted for night: These birds have evolved to have keen hearing and silent flight to aid in their nocturnal activities. Their feathers are designed to dampen sound, making them stealthy hunters.
In conclusion, the boy likely observed a nocturnal bird with black and white vision flying swiftly through the night, showcasing its unique adaptations for hunting and survival in low light conditions.

Understanding Cuscuta
Cuscuta, commonly known as dodder, is a genus of parasitic plants that exhibit unique characteristics distinguishing them from other plant types. It primarily relies on other plants for its nutrients, making it a classic example of a parasite.
Characteristics of Cuscuta
- Parasitic Nature:
- Cuscuta does not have chlorophyll, which means it cannot perform photosynthesis to create its own food. Instead, it attaches to host plants using specialized structures called haustoria.
- Nutrient Absorption:
- Through its haustoria, Cuscuta taps into the vascular system of the host plant to extract water and essential nutrients, thereby sustaining itself.
Differences from Other Categories
- Autotrophs:
- These organisms can synthesize their own food using sunlight or chemical energy. Cuscuta does not fit into this category as it lacks chlorophyll.
- Saprotrophs:
- Saprotrophic organisms decompose organic matter to obtain nutrients. Cuscuta, on the other hand, requires a living host for sustenance.
- Host:
- The term "host" refers to the organism that provides sustenance to a parasite. In this case, the host is the plant that Cuscuta attaches itself to.
Conclusion
In summary, Cuscuta is an example of a parasite due to its dependence on other plants for survival. Its unique adaptations enable it to thrive by extracting nutrients from its hosts, showcasing the complex relationships within ecosystems.

Plumule develops into stem and leaves. Thus, it forms the shoot system of the plant.

Skin patterns like stripes and patches are adaptations to the environment. They help in camouflage and survival in different weather conditions. Hence, option D is correct.

Pollination is essential for formation of seeds. It helps in reproduction of flowering plants.

Onion is a modified underground stem (bulb). Turnip, radish and carrot are modified roots.

Stomata allow exchange of gases for respiration and photosynthesis. They also help in transpiration.

Autotrophs make their own food using sunlight and chlorophyll. Heterotrophs depend on plants or other animals for food. Therefore, both statements are correct.

Oviparous animals lay eggs like birds, reptiles, and amphibians. Mammals generally give birth to young ones directly. Therefore, mammals are not oviparous.

Phloem transports food prepared in the leaves. This food is carried to other parts of the plant.

Plants absorb carbon dioxide during photosynthesis. Oxygen is released as a by-product.

Rhizophora grows in swampy areas and develops pneumatophores. These roots grow away from gravity for respiration.

Whale is a mammal and breathes through lungs, not gills. Gills are mainly present in fishes. Therefore, “Whale : respiration through gills” is not correctly matched.

Adventitious roots are thin and moderately branched. They do not have one dominant central root.

The described animal sleeps for long hours and hangs upside down on trees. It also eats leaves and lives for many years. These features match a sloth.

Some animals are domesticated not only for products but also for entertainment. According to the provided key, hen is considered an entertainment source here. Hence option C is marked correct.

Animal husbandry refers to scientific care, management, and breeding of animals. It focuses on improving productivity like milk, meat, wool, etc. Therefore, option B is correct.

Biotic factors include living organisms like plants, animals, and microbes. Stones are non-living and part of the abiotic environment. Hence, option D is correct.

Plants store prepared food mainly as carbohydrates (starch). This stored food is used later for growth and energy.

Chlorophyll is required for photosynthesis. Mushrooms lack chlorophyll, so they cannot make food.

Oviparous animals lay eggs and external fertilisation happens outside the body. Viviparous animals give birth, so they do not lay eggs, making statement III wrong. Hence, I, II and IV are correct.

Mammals give birth to young ones and feed them with milk. Bat gives birth instead of laying eggs. Hence, bat is a mammal and option D is correct.

Fishes have scales and mostly lay eggs, so they are oviparous. They also possess a two-chambered heart and have invisible ears. Thus, all the statements are correct.

Climbers have weak stems and grow upward using support. Example: pea plant and grapevine.

Banana has a pseudostem formed by leaf bases. It is not a true woody stem like trees.

Photosynthesis happens mainly in green leaves. It uses sunlight, chlorophyll, CO₂ and water to form food.

Some birds choose thorny places for nests to protect themselves from predators. Dove is known to build its nest among cactus thorns. Therefore, option C is correct.

Snakes are vertebrates and monkeys are mammals as they have a backbone and give birth. The question includes multiple correct pairs. Therefore, the answer is “All of these”.

Root, leaves and stem are parts of a plant. Habitat means the place where a plant lives.

Wheat has a soft and weak stem. Therefore, it is classified as a herb.