Assertion: Animals that are aquatic rather than terrestrial can support relatively larger exoskeletons.
Reason: The terrestrial organisms are relatively larger than aquatic animals.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: For moving on land, powerful muscles and strong skeletal support are more important than a streamlined shape.
Reason: Land animal must be able to support itself and move against gravity.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

In humans, marrow is colloquially characterized as "red" or "yellow" marrow where the latter:

1. makes RBCs but not WBCs.

2. is found in flat bones only.

3. makes WBCs but not RBCs.

4. mostly adipose tissue.

If a stimulus, several times greater than the threshold stimulus, is provided to a muscle fiber, it will
1. Contract with a larger force
2. Contract with a smaller force
3. Contract with the same force
4. Undergo tetany

Acetylcholinesterase:

1. helps in binding of acetylcholine to its receptors.

2. catalyzes the synthesis of acetylcholine from acetate and choline.

3. stimulates receptors within the postsynaptic membrane.

4. breaks down acetylcholine.

During relaxation in smooth muscle:

1. calcium is removed from troponin.

2. ${\mathrm{Ca}}^{2+}$ bind to calmodulin.

3. myosin phosphatase removes phosphate from myosin.

4. Calcium is released from the sarcoplasmic reticulum.

A type of strength training in which the joint angle and muscle length do not change during contraction is termed as:

1. isometric contraction.

2. isotonic contraction.

3. concentric contraction.

4. eccentric contraction.

Exposure to Sarin, a nerve gas will cause all the following except:

1. Failure to release acetylcholine at the neuromuscular junction

2. Prolonged depolarization of the motor end plate

3. Paralysis eventually leading to death

4. Inability to break down acetylcholine

Assertion: Myoglobin needs to have a higher affinity for oxygen than hemoglobin.
Reason: To perform its job, myoglobin must effectively bind any oxygen released from hemoglobin.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Trained athletes have an increased proportion of energy derived from aerobic respiration of fatty acids.
Reason: Any adaptation that spares muscle glycogen will improve physical endurance.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.