SSC CGL (Prelims) GK: Biology questions with solutions

Q1. What do we mean by Allen's rule?

1. Mammals from colder climates generally have shorter ears and limbs to minimise heat loss.
2. Desert lizards lack the physiological ability that mammals have to deal with the high temperatures of their habitat.
3. Some plants have no leaves; they are reduced to spines, and the photosynthetic function is taken over by the flattened stems.
4. The body compensates low oxygen availability by increasing red blood cell production, decreasing the binding affinity of haemoglobin and by increasing the breathing rate.

Answer: Mammals from colder climates generally have shorter ears and limbs to minimise heat loss.

Allen's rule states that endothermic animals in colder climates tend to have shorter extremities such as ears, tails, and limbs. This reduces surface area and helps conserve body heat. Hence, the option about shorter ears and limbs is correct.

Q2. Which of the following types of venation is found in grasses?

1. Cubical venation
2. Radial venation
3. Rectangular venation
4. Parallel venation

Answer: Parallel venation

Grasses are monocots, and monocot leaves typically show parallel venation. In this pattern, the veins run parallel to each other along the length of the leaf.

Q3. Which of the following characteristics is NOT of Aves?

1. They have four-chambered heart.
2. They give birth to live young ones with some exceptions those lay eggs.
3. These are warm-blooded animals.
4. They breathe through the lungs

Answer: They give birth to live young ones with some exceptions those lay eggs.

Aves are birds, and they are generally oviparous, meaning they lay eggs. They are warm-blooded, have a four-chambered heart, and breathe through lungs.

Q4. Which cell organelle is a small, round organelle that undergoes oxidation reactions to produce hydrogen peroxide?

1. Centrosome
2. Vacuole
3. Nucleus
4. Peroxisomes

Answer: Peroxisomes

Peroxisomes are small membrane-bound organelles involved in oxidation reactions. They produce hydrogen peroxide and contain catalase to decompose it.

Q5. Hubbardia heptaneuron, which has become endangered, is a species of which of the following?

1. Grass
2. Bamboo
3. Tiger
4. Crane

Answer: Grass

Hubbardia heptaneuron is an endangered species of grass. It is a rare plant found in specific regions and is known for its conservation significance.

Q6. Name the hormone responsible for the "fight or flight" response in humans.

1. Adrenaline
2. Thyroxine
3. Insulin
4. Estrogen

Answer: Adrenaline

Adrenaline, also called epinephrine, is released by the adrenal medulla during stressful situations. It increases heart rate, blood pressure, and energy availability, producing the fight-or-flight response.

Q7. Which element is required for the process of photosynthesis?

1. Nitrogen
2. Oxygen
3. Carbon Dioxide
4. Hydrogen

Answer: Carbon Dioxide

Photosynthesis uses carbon dioxide and water to produce glucose in the presence of sunlight and chlorophyll. Oxygen is released as a by-product, not required as an input.

Q8. Which blood group is known as the universal donor?

1. O+
2. O−
3. AB+
4. A−

Answer: O−

The universal donor for red blood cell transfusion is O negative because its red blood cells do not have A, B, or Rh antigens. This makes it least likely to cause an immune reaction in recipients of other blood groups.

Q9. Which vitamin is produced in the human body when exposed to sunlight?

1. Vitamin A
2. Vitamin B12
3. Vitamin C
4. Vitamin D

Answer: Vitamin D

When skin is exposed to sunlight, it synthesizes vitamin D. This vitamin is important for calcium absorption and bone health.

Q10. In which organ of the human body is bile produced?

1. Stomach
2. Gallbladder
3. Liver
4. Pancreas

Answer: Liver

Bile is produced in the liver and stored in the gallbladder. It helps in the digestion of fats.

Q11. Which gas is essential for photosynthesis to occur?

1. Nitrogen
2. Oxygen
3. Carbon Dioxide
4. Hydrogen

Answer: Carbon Dioxide

Carbon dioxide is required by plants during photosynthesis to produce glucose. Oxygen is released as a by-product, not used as the essential input gas.

Q12. Which part of the human brain is responsible for balance and coordination?

1. Cerebrum
2. Cerebellum
3. Medulla
4. Pons

Answer: Cerebellum

The cerebellum controls balance, posture, and coordination of voluntary movements. The cerebrum handles thinking, while the medulla and pons are involved in involuntary functions.

Q13. Which vitamin is produced when the human skin is exposed to sunlight?

1. Vitamin A
2. Vitamin B12
3. Vitamin C
4. Vitamin D

Answer: Vitamin D

When skin is exposed to sunlight, the body synthesizes vitamin D. This vitamin is important for calcium absorption and bone health.

Q14. Which gas is essential for human respiration?

1. Carbon dioxide
2. Nitrogen
3. Oxygen
4. Hydrogen

Answer: Oxygen

Oxygen is essential for human respiration because cells use it to release energy from food. Humans inhale oxygen and exhale carbon dioxide.

Q15. Which vitamin helps in blood clotting?

1. Vitamin A
2. Vitamin C
3. Vitamin K
4. Vitamin D

Answer: Vitamin K

Vitamin K is necessary for the synthesis of proteins involved in blood clotting. A deficiency of vitamin K can lead to excessive bleeding.

Q16. Which gas do plants absorb from the atmosphere?

1. Oxygen
2. Carbon Dioxide
3. Nitrogen
4. Hydrogen

Answer: Carbon Dioxide

Plants absorb carbon dioxide from the atmosphere for photosynthesis. They use it, along with water and sunlight, to prepare food.