All Free Biology MCQs with Answers

1921. Entamoeba histolytica is a parasite found in man's__________?

• A. Liver
• B. Intestines
• C. Lungs
• D. Kidneys

Explanation: Entamoeba histolytica usually inhabits the large intestine, where it can cause amoebic dysentery, although it may sometimes spread to the liver. Students may choose liver because liver abscess is a serious complication, but the usual primary site of the parasite is the intestine.

1922. The hepatic portal vein drains blood to liver from___________?

• A. Intestine
• B. Stomach
• C. Kidney
• D. Heart

Explanation: The hepatic portal vein carries nutrient-rich blood from the digestive tract to the liver for processing and detoxification, so the intestine is the best option. Students may choose the kidney because it also receives blood for processing, but blood reaches it through the renal artery, not the hepatic portal vein.

1923. In the human body Gall bladder is the part of the ___________ system?

• A. Nervous
• B. Reproductive
• C. Digestive
• D. Respiratory

Explanation: The gallbladder belongs to the digestive system because it stores and concentrates bile made by the liver, releasing it into the small intestine to help digest fats. Students may choose the respiratory system because both systems contain internal organs, but the gallbladder has no role in breathing.

1924. Stimulus for CCK hormone is___________?

• A. Fat, Protein
• B. Acid
• C. Base
• D. Both A & B

Explanation: Cholecystokinin, or CCK, is released mainly when fats and partially digested proteins enter the small intestine, and it stimulates pancreatic enzyme secretion and gallbladder contraction. Acid is the main stimulus for secretin, so students may select both A and B by confusing secretin's stimulus with CCK's.

1925. Which of the following secrete hydrochloric acid in stomach?

• A. Mucosa
• B. Goblet
• C. Epithelial
• D. Oxyntic

Explanation: Oxyntic cells, also called parietal cells, secrete hydrochloric acid in the gastric glands and help create the acidic stomach environment. Goblet cells secrete mucus, so students may choose them because mucus and acid are both components of gastric juice.

1926. Another name for liver is called ___________ ?

• A. Hepar
• B. Hepta
• C. Heptum
• D. Hilum

Explanation: Hepar is the anatomical and Latin name for the liver, which performs functions such as bile production, detoxification and nutrient storage. Students may choose hilum, but a hilum is an indentation or entry point on an organ, not another name for the liver.

1927. Liver fluke is parasite in the liver of__________?

• A. cattle
• B. sheep
• C. goat
• D. all of these

Explanation: Liver flukes such as Fasciola hepatica live in the bile ducts and liver of grazing mammals, commonly sheep, cattle, and goats, so all three can serve as hosts. The likely mistake is choosing sheep alone because sheep are the classic host often mentioned in textbooks.

1928. In all coelentrates endoderm give rise to__________?

• A. nervous system
• B. digestive system
• C. reproductive system
• D. circulatory system

Explanation: In coelenterates, the endoderm forms the gastrodermis, which lines the gastrovascular cavity and carries out digestion. Students may choose the nervous system because it is an important body function, but nervous structures arise mainly from the ectoderm, not the endoderm.

1929. The utilization of the products of digestion is called___________?

• A. ingestion
• B. absorption
• C. assimilation
• D. both a and b

Explanation: Assimilation is the use and incorporation of absorbed nutrients into the body's cells for energy, growth, and repair. Absorption only describes the movement of digested nutrients through the intestinal wall into blood or lymph, so option b is a common confusion.

1930. Villi and microvilli increase__________?

• A. digestion
• B. assimilation
• C. absorption
• D. ingestion

Explanation: Villi and microvilli greatly increase the surface area of the small intestine, allowing digested nutrients to pass more efficiently into blood and lymph. They do not primarily increase digestion itself, so option a is the likely choice of students who confuse nutrient breakdown with nutrient uptake.