Assertion: In animals, chemical digestion is necessary.
Reason: Mechanical digestion, typically, precedes chemical digestion, increasing the surface area for chemical digestion.

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.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion: The secretion of bile by liver is important physiologically as it helps in the digestion and absorption of fats.
Reason: Bile contains bile pigments that help in first emulsification of fats and later absorption of fatty acids and glycerol through micelle formation.

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: The liver is the first organ to receive most of the products of digestion except for fat.
Reason: Blood from the liver is drained by the hepatic vein.

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: In the stomach, chief cells release pepsinogen and not pepsin.
Reason: This zymogen is activated by hydrochloric acid (HCl), which is released from parietal cells in the stomach lining.

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: The muscularis externa of the stomach is unique from other organs of the gastrointestinal tract.
Reason: It does not have the Auerbach’s or myeneteric plexus.

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: The active absorption of calcium in the intestine requires the presence of Vitamin D.
Reason: Vitamin D is activated in kidney under the influence of parathyroid hormone.

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.

An innermost oblique muscle layer is present in the wall of: 

Which of the following digestive juices has the minimum pH value?
1. Bile
2. Gastric juice
3. Saliva
4. Pancreatic juice

The drug acetyl salicylic acid is quickly absorbed in:
1. Duodenum
2. Stomach
3. Jejunum
4. Ileum

Hormonal control of the secretion of digestive juices is carried out by:

1. local hormones produced by the gastric and intestinal mucosa

2. hypothalamic hormones

3. hormones of the anterior pituitary gland

4. hormones of adrenal cortex