All Free Biology MCQs with Answers

• A. Renin
• B. Personage
• C. Rennin
• D. Gastrin

Explanation: Rennin, also known as chymosin, is the correct answer. It is an enzyme found in the gastric juice of many infant mammals, including…

• A. Buccal chamber
• B. intestine
• C. rectum
• D. intestinal caccum

Explanation: In earthworms, the esophagus connects the pharynx to the crop and then continues to the gizzard.

• A. Rennin
• B. Pepsinogen
• C. Gastrin
• D. Renin

Explanation: Rennin is an enzyme found in the gastric juice of many infant mammals, including humans, that helps to digest milk proteins.

• A. oesophagus
• B. mouth
• C. stomach
• D. duodenum

Explanation: The correct answer is the stomach. The stomach is crucial for mechanical digestion as it churns and mixes the food, breaking it down into…

• A. Cholic acid
• B. Biliverdin
• C. Haemoglobin
• D. Both (A) and (B)

Explanation: Bile salts are synthesized in the liver from cholesterol-derived bile acids such as cholic acid.

• A. Stomach
• B. Duodenum
• C. Ileum
• D. Colon

Explanation: Brunner's glands are branched tubular mucus glands normally found in the mucosa and submucosa of the duodenum. Therefore the answer is B.

• A. Polypeptides
• B. Carbohydrates
• C. Dipeptides
• D. Fats

Explanation: Erepsin consists of many enzymes and works best in alkaline pH. It doesn't act upon proteins but does act upon lower peptides such as…

• A. Gastrin
• B. Cholecystokinin
• C. Secretin
• D. Renin

Explanation: When stimulated by the cholecystokinin (CCK), the gallbladder contracts pushing bile through the cystic duct and into the common bile duct.

• A. Mucus cells
• B. Parietal cells
• C. Hormonal cells
• D. Chief cells

Explanation: Pepsinogens are synthesized and secreted primarily by the gastric chief cells of the human stomach before being converted into the…

• A. Throat
• B. Pharynx
• C. Medulla oblongata
• D. Stomach

Explanation: The swallowing process is primarily regulated by the medulla oblongata, which is part of the brainstem.

• A. Obesity
• B. Bulimia nervosa
• C. Dyspepsia
• D. Anorexia nervosa

Explanation: Bulimia nervosa is characterized by recurrent episodes of binge eating, wherein individuals consume large amounts of food, often high in…

• A. 10-20 Acinars
• B. 20-40 Acinars
• C. 20-30 Acinars
• D. 30-40 Acinars

Explanation: The pancreatic acinar cell is a highly specialised structure developed for synthesis, storage, and secretion of digestive enzymes.

• A. Kupffers cells
• B. Hansans cells
• C. Lupffers cells
• D. Aciner cells

Explanation: The cells in the liver that are associated with phagocytosis are called Kupffer cells.

• A. Duodenum
• B. Jejunum
• C. Ileum
• D. Colon

Explanation: Option A is correct. The first segment of the small intestine is the duodenum.

• A. semi lunar valve
• B. tricuspid valve
• C. bicuspid valve
• D. semicircular valve

Explanation: The opening between the right atrium and right ventricle is guarded by the tricuspid valve.

• A. Pure blood to body
• B. Impure blood to body
• C. Pure blood to gills
• D. Impure blood to gills

Explanation: In fishes, the heart pumps out deoxygenated blood from the body to the gills where it gets oxygenated.

• A. Semi lunar valve
• B. Tricuspid valve
• C. Pulmonary valve
• D. Bicuspid valve

Explanation: The bicuspid valve, also known as the mitral valve, is the correct answer because it is located between the left atrium and left…

• A. Smooth muscles
• B. Myogenic muscles
• C. Striated muscles
• D. Skeletal muscles

Explanation: The heart muscles are called myogenic muscles because they can contract on their own without direct nerve stimulation.

• A. bicuspid valve
• B. tricuspid valve
• C. pulmonary valve
• D. semi lunar valve-

Explanation: The valve between the right atrium and the right ventricle is the tricuspid valve.

• A. Semi lunar valve
• B. Blcuspid valve
• C. Tricuspid valve
• D. Pulmonary valve

Explanation: The term semilunar refers to the aortic valve and the pulmonary valve, tricuspid is the valve between the right atrium and ventricular and…