Olympiad Test: Animals - 2 - Class 6 MCQ

The bat is odd in the given group of animals because it does not have feathers.

• The defining characteristic of birds is feathers, which distinguishes them from mammals like bats. While bats can fly and may share some other characteristics with birds, they are mammals, and mammals have fur or hair, not feathers.

So, Option D is the correct answer because it highlights the key difference between bats (which are mammals) and birds (which have feathers).

Both bats and dolphins use echolocation.

• Bats use echolocation to navigate and hunt for food in the dark. They emit high-frequency sound waves, which bounce off objects and return, allowing them to "see" their surroundings through sound.
• Dolphins also use echolocation in the water to detect objects, prey, and navigate in their environment. They emit clicks that travel through water and bounce back when they hit an object.

Thus, Option C (Both of these) is the correct answer.

The poisonous teeth of snakes are called fangs.

• Fangs are specialized, sharp teeth used by venomous snakes to inject poison into their prey.
• Feet (Option A) are limbs, which snakes do not have.
• Fins (Option C) are found in aquatic animals like fish, not in snakes.
• None of these (Option D) is incorrect because fangs are indeed the poisonous teeth of snakes.

The following features are flight adaptations in birds:

• I: Their body shape – Birds have a streamlined body shape that reduces air resistance during flight.
• II: Smooth waxy feathers – Birds have specialized feathers that help with aerodynamics and waterproofing, aiding in flight.
• III: Hollow bones – Birds have lightweight, hollow bones, which reduce their body weight, making it easier to fly.
• IV: Beaks – While beaks are characteristic of birds, they are not directly related to flight. Beaks are adapted for feeding, not flying.

Therefore, the correct answer is Option C (Only I, II, and III), as these features are specifically adaptations for flight.

Aquatic animals move easily in the water using the following adaptations:

• I: A streamlined body – Reduces resistance while swimming, making movement easier in water.
• III: Webbed feet – Act like paddles to help aquatic animals swim efficiently.
• V: Fins – Provide stability and control in the water, aiding in swimming.

Breathing tubes (II) and gills (IV) are essential for respiration but not directly involved in movement. Therefore, the correct answer is Option B (Only I, III, and V).

The correct statements are:

• (ii) Monarch butterflies travel from Canada to Mexico during the winter season – Monarch butterflies are known to migrate thousands of miles from Canada and the northern United States to Mexico for the winter.
• (iv) Siberian cranes come to India during winter – Siberian cranes migrate to India during the winter months, particularly to places like the Keoladeo National Park in Rajasthan.

The other statements are incorrect:

• (i) Arctic tern travels from Antarctic to Arctic in winter – The Arctic tern actually travels from the Arctic to the Antarctic for winter, not the other way around.
• (iii) Salmons swim long distances to reach sea to lay eggs – This is incorrect because salmon typically swim from the sea to freshwater rivers to lay their eggs, not the other way around.

Therefore, the correct answer is Option B (ii) and (iv).

The surroundings in which an animal lives and grows is called its habitat.

• Habitat refers to the natural environment where an organism lives, finds food, and grows. It includes factors like shelter, food, and climate.
• Climate (Option A) refers to the weather conditions in a particular area but does not specifically describe the place where an animal lives.
• Behavior (Option C) refers to the actions or reactions of an animal in response to its environment, not the environment itself.
• None of these (Option D) is incorrect because habitat is the right term.

Therefore, the correct answer is Option B (Habitat).

The long winter sleep is called hibernation.

• Hibernation is a period of inactivity and metabolic depression in endotherms (like some mammals) during cold weather. Animals, such as bears, bats, and hedgehogs, enter hibernation to conserve energy when food is scarce and temperatures are low.
• Nap (Option B) is a short, light sleep, not related to long winter sleep.
• Nocturnal (Option C) refers to animals that are active at night, not a type of sleep.
• None of these (Option D) is incorrect because hibernation is the correct term.

Therefore, the correct answer is Option A (Hibernation).

A frog is an amphibian that breathes both through its skin and lungs.

• Frogs use their skin for respiration when they are in water (cutaneous respiration) and lungs for breathing air when they are on land (pulmonary respiration).
• Therefore, Option Y (Animals breathing by skin and lungs) represents a frog.

Thus, the correct answer is Option Y.

The earthworm is often called the "friend of farmers" because it plays a crucial role in improving soil quality.

• Earthworms aerate the soil as they burrow, which allows better water infiltration and root growth.
• They also help in the decomposition of organic matter, turning it into rich, fertile humus, which enhances soil fertility for better crop growth.

The other organisms listed are not as beneficial for farming:

• Leech (Option B) is a parasitic organism that feeds on blood.
• Sycon (Option C) is a type of simple sponge, not related to farming.
• Ascaris (Option D) is a parasitic roundworm, which is harmful to humans and animals.

Thus, the correct answer is Option A (Earthworm).