EVS Content (Birds & Insects) - CTET & State TET MCQ

Key Points

Feathers:

• The feathers of birds have different colours, shapes, and sizes.
• Feathers help birds to fly by providing lift and maneuverability.
• Feathers also serve multiple functions, including:
  • Keeping birds warm by providing insulation and trapping air close to the body.
  • Helping birds maintain their body temperature in colder environments.
  • Assisting in flight control and stability.
  • Facilitating courtship displays and communication through vibrant colours and patterns.
  • Providing camouflage to blend in with their surroundings and avoid predators.
  • Aiding in balance and coordination during various activities, including walking, perching, and climbing.
  • Protecting the skin and underlying body structures from external elements and potential injuries.
  • Supporting buoyancy for water-dwelling birds by repelling water and enabling swimming.
  • Providing a lightweight and efficient surface for flying while minimizing energy expenditure.
  • Among these functions, the feathers of birds play a crucial role in keeping them waterproof and warm, allowing them to adapt to their environments and engage in various activities necessary for survival.

​Thus,

A. eat different types of food: Incorrect

B. keep them warm: Correct

C. walk in different ways: Incorrect

D. keep them waterproof: Correct 

​Explanation:

Earthworm:

• The earthworm is a reddish-brown terrestrial invertebrate.
• They inhabit the upper layer of the moist soil.
• During day time, they live in burrows made by boring and swallowing the soil.
• Earthworms play a vital role in the natural cycle of the earth.
• The Earthworms soften the soil by digging underneath to make tunnels.
• They play a crucial role in breaking down organic matter and fertilising the soil, simply through their constant eating and pooping.
• Earthworms can be used for fishing and compost.
• Worms are important to the ecosystems in which they live and breed.
• They are known as farmers friends as their compost helps in enriching the soil and give bountiful produce.
• Kingdom: Animalia
• Phylum: Annelida
• Class: Clitellata
• Family: Lumbricidia

Important Points 

Earthworms are useful in several ways for farmers:

• Earthworms make the soil porous by digging burrows in the soil. Hence they are called friends of the farmers.
• The nitrogenous wastes and other waste products of the earthworms form food for plants. This process of increasing the fertility of the soil by earthworms is called vermicomposting.
• Earthworms are used as fish bait to catch fish.
• Some tribals in India use earthworms as medicine to cure jaundice, piles, diarrhoea, bladder stones, etc.
• The earthworms reduce both acidity and alkalinity of the soil and create optimum conditions for plant growth.
• The density of earthworms in the soil is considered to be a good indicator of healthy soil because they increase the soil's water-holding capacity and moisture content.

Thus,

A) Earthworms soften the soil of the field in which they live by digging the soil underneath. - Correct

B) The tunnels dug by earthworms provide easy passage for air and water into the soil. - Correct

C) The earthworms eat the weeds and save the main crop. - Incorrect

D) The earthworms eat the dead leaves and plants. The dropping of the earthworms make the soil more fertile - Correct.

Explanation:

• Some animals are active during the day while others are active at night 
• Those that are active at night are known as nocturnal animals.
• Animals who live in the desert are usually nocturnal to avoid the intense heat during the day
• Those animals that are awake at night can see things only in black and white colours.
• Their eyes are modified to enhance vision during the night such as they have very large pupils eg, owls

Additional Information 

• Examples of Nocturnal Animals: Bats, Desert Rats, Desert snakes, Owls etc
• Other adaptations found in desert animals are high water storage capacity eg, camel
• Camel is called Ship Of Desert
• Similar to animals, desert plants also are different from plants found in other regions

∴ There are animals that awake at night. These birds are known as Nocturnal bird.

Key Points

Binocular vision:

• While those with eyes on the front of their heads have binocular vision.
• Such birds can estimate distances when hunting.
• They have to move their heads to see around. 
• The binocular vision of birds makes them see distinctly.
• Example: Owl, Crows, Doves, Peacock, Nightingales, Parrots, Pigeons etc.

Concept:

• Insects have different senses.
• They can see, hear, taste, smell and feel.
• Some animals can see their prey from far away.
• Some can hear even the faintest sound.
• Some insects can find their friends by their smell.

Explanation:

• As the ants move, they leave a smell on the ground.
• The other ants follow the smell to find the way.
• The smell is recognised and identified by the members of the same group only.
• An ant thus uses its smell as an identity proof.

Thus, the ant knows that the other ants were not from its group through their smell.

Concept:

• Different birds have different types of vision.
• The type of vision they have depends on their source of food.

Explanation:

Monocular vision:

• Birds with eyes on the sides of their heads have a wide visual field.
• It is useful for detecting prey.
• Such birds can focus on two different things at a time.
• When they look straight ahead, both their eyes focus on the same object.
• They don't have to move their heads to see around.
• They can see four times as far as we can.
• Example: Kites, Eagles, Vultures.

Binocular vision:

• While those with eyes on the front of their heads have binocular vision.
• Such birds can estimate distances when hunting.
• They have to move their heads to see around. 
• The binocular vision of birds makes them see distinctly.
• Example: Owl, Crows, Doves, Peacock, Nightingales, Parrots, Pigeons etc.

Thus, Kites, Eagles and Vultures can see up to 8 meters away.

Colony-

• The colony is composed of two or more co-relative individuals which remain in close association with one another.
• Some insects like bees, ants, wasps and termites, live together in groups called colonies.
• Hence, they are called colonial insects.

Key-Points

About Wasps:

• Every wasp colony consists of three types of wasps:
  • Queen: Every hive has one Queen that lays eggs.
  • Male: There are only a few males in the hive. The males have no special role as workers. 
  • Worker: Most of the wasps in the hive are worker wasps. They work all day. They make the hive and also look after the baby wasps. The worker wasps are very important for the hive. 

Ant:

In the colony of ants, work is assigned as

• It is usually seen that ants follow one another. The main reason behind this is that ants secrete an invisible chemical named trail pheromone.
• This chemical scent help to reach the food source from the nest.
• Using this scent, other fellow ants follow the one 'queen ant' unless they reach the food.
• As soon as the food disappears, the ants no longer secrete scents and the trail fades away. 

Explanation:

Social insects are best exemplified by all termites (Isoptera; sometimes Blattodea) and ants (Formicidae) and by various bees and wasps (Hymenoptera).

• Social insects are differentiated in structure, function, and behaviour into castes, the major ones being the reproductives (e.g., the queen) and the steriles (workers and soldiers).
• Besides carrying out the basic function of reproduction, the members of the reproductive caste generally select the site for a new colony and excavate the first galleries.
• The workers care for the eggs and larvae, collect food for other members of the colony, and construct and repair the nest, while the soldiers defend the colony against predators.
• They establish fungus gardens and feed on them.

Hence spider, mosquito and housefly are not a colonial insect and is the correct option.

Concept:

• Birds build nests to lay their eggs and incubate their younger ones.
• Different birds build nests at different places, some on ground level, some high up on the tree.
• Different birds use different techniques and different materials to build their nests.

Explanation:

Sunbird:

• They are tiny birds.
• These are usually seen during dawn.
• They make a tiny nest hanging from the branch of a small tree or shrub.
• Nest is usually made up of:
  • Hair
  • Grass
  • Dry leaves
  • Cloth pieces. 

Additional Information

Barbet:

• It is a tropical bird constituting the family Capitonidae.
• Barbets are named for the bristles at the bases of their stout, sharp bills.
• They are big-headed, short-tailed birds, 9–30 cm long, greenish or brownish, with splashes of bright colours or white.
• The distribution of the family spans Central America to northern South America; sub-Saharan Africa; and Southeast Asia, eastward only to Borneo and Bali.
• All are non-migratory.
• Barbets sit stolidly in treetops when not feeding on insects, lizards, birds’ eggs, fruit, and berries.
• Some climb like woodpeckers; all fly weakly.
• The nest is a hole, dug with the beak, high up in a rotting tree or in a termite nest.

Koyel:

• It is a crow size bird, with a similar appearance.
• It does not make its own nest.
• Crow makes a nest for it.

Indian robin:

• It makes its nest on the roadside between stones or grasslands.
• It is covered with twigs, cotton, and wool.

Tailorbird:

• It is a small bird with a long tail.
• It makes its nest by switching the two leaves together.

Concept:

• The honeybee is an insect belonging to the genus Apis.
• Honeybees are excellent pollinators.
• They collect nectars from flowers and help in transferring their pollen.
• Honeybees are commercially exploited to extract honey from their hives.

Explanation:

• Because of the many benefits of honey, beekeeping becomes very profitable commercially.
• Many state governments run programs to train young students in beekeeping.
• In the training, the following things can be learned:
  • Types of flowers that attract honeybees: Honeybees are attracted to litchi flowers.
  • The egg-laying pattern of honeybees: Honeybees lay their eggs from October to December.
  • The best time to start beekeeping is October to December.

Thus;

A. Honeybees are attracted to the litchi flowers. Correct

B. Honeybees lay their eggs from January to March. Incorrect

C. October to December is the best time to start beekeeping. Correct

Additional InformationAbout honeybee:

• Honeybees live in colonies with one queen running the whole hive.
• Worker honeybees are all females.
• Worker bees are the only bees most people ever see flying around outside of the hive.
• They forage for food, build honeycombs, and protect the hive.
• Male bees are called drones. 

Concept:

• Animals have different senses.
• The animal world is full of examples of amazing senses.

Explanation:

Silkworm: 

• The silkworm is the larva or caterpillar of the Bombyx mori moth.
• The moth is important because it makes silk.
• It is entirely dependent on humans, and it no longer lives in the wild. 
• Silkworms eat mulberry leaves and are native to northern China.
• Some male insects can recognise their females by their smell. 
• Silkworms can find their female worm from many kilometres away by their smell.

​Thus, a silkworm can find its female by its smell.

Additional Information Earthworm:

• The earthworm is a reddish-brown terrestrial invertebrate.23
• They inhabit the upper layer of the moist soil.
• During day time, they live in burrows made by boring and swallowing the soil.
• Earthworms play a vital role in the natural cycle of the earth.
• The Earthworms soften the soil by digging underneath to make tunnels.
• They play a crucial role in breaking down organic matter and fertilising the soil, simply through their constant eating and pooping.
• Earthworms can be used for fishing and compost.
• Worms are important to the ecosystems in which they live and breed.
• They are known as farmers friends as their compost helps in enriching the soil and give bountiful produce.

Tapeworm:

• Tapeworm is a parasite that is found in our intestines and goes into our bodies due to lack of cleanliness.
• Generally, it does not cause any direct harm.
• But increasing your numbers can make you very sick. In some cases, an operation has to be done.
• To avoid this, hands should always be washed thoroughly before eating food.
• Raw vegetables and meat should not be eaten. And give priority to all types of food in food.
• Don't just eat vegetables of your choice, but eat all kinds of food.

Flatworm:

• Flatworms are also called planarians.
• They belong to the phylum Platyhelminthes.
• They are characterized by flat bodies, they have no skeleton, no circulatory or respiratory organs, etc.

Concept:

• Delhi's former Chief Minister Sheila Dixit raised her concern about the decreasing number of Humble house sparrows in Delhi.
• Due to urbanization on a large scale, the birds lost their natural habitat and fails to build nests. Causing them to disappear. 
• Mobile radiation and Telecom towers are enemies of Sparrows. 
• They navigate by sensing the earth's magnetic field but the Tv towers and telephone towers disturb the earth's magnetic field and thus they are unable to locate their home. 
• Thus, the Chief Minister of Delhi declared the Humble home sparrow as the state bird of Delhi to raise awareness about it. 

Explanation:

The bird was a common sight in Delhi but now a special day is observed to raise awareness about the bird as it has become rare due to the urbanization. The bird is a sparrow.

Additional Information