Physiology MCQs Set 1
1. Which subject deals with the integrated functions of the body?
a. Histology b. Anatomy c. Physiology d. Psychology
✅ Correct Answer: c. Physiology
Explanation: Physiology is the branch of biology specifically focused on the functions and mechanisms of living organisms and how their parts work together.
2. Which functional groups are formed by the association of various tissues?
a. System b. Body c. Skeleton d. Organ
✅ Correct Answer: d. Organ
Explanation: In the biological hierarchy, a group of different tissues working together to perform a specific function forms an organ.
3. What is the thickness of cell membrane?
a. 70-100 Å b. 100-150 Å c. 30-60 Å d. 10-20 Å
✅ Correct Answer: a. 70-100 Å
Explanation: The cell membrane (plasma membrane) is typically about 7.5 to 10 nanometers thick, which converts to 70–100 Angstroms (Å).
4. The properties of cell that are equated with those of life includes:
a. Growth b. Reproduction c. Metabolism d. All
✅ Correct Answer: d. All
Explanation: A living cell exhibits all the fundamental characteristics of life, including growth, reproduction, and metabolism.
5. Failure of a tissue or organ to develop is called:
a. Hypoplasia b. Aplasia c. Neoplasia d. Alopecia
✅ Correct Answer: b. Aplasia
Explanation: Aplasia is the technical term for the complete failure of a tissue or organ to develop. Hypoplasia refers to under-development.
6. Following processes can occur across the cell membrane at the same time:
a. Osmosis b. Active transport c. Both d. None of them
✅ Correct Answer: c. Both
Explanation: The cell membrane is dynamic and can perform passive processes (like osmosis) and active processes (like active transport) simultaneously depending on the cell’s needs.
7. The process of taking dissolved material into the substance of the cell is called:
a. Phagocytosis b. Pinocytosis c. Absorption d. Diffusion
✅ Correct Answer: b. Pinocytosis
Explanation: Known as “cell drinking,” pinocytosis is the type of endocytosis where the cell engulfs extracellular fluid and dissolved solutes.
8. The process by which cell can take in fluid and molecules too large to be carried across the plasma membrane by active transport is called:
a. Phagocytosis b. Pinocytosis c. Absorption d. Diffusion
✅ Correct Answer: b. Pinocytosis
Explanation: This refers to the same process as the previous question; pinocytosis allows the uptake of fluids and large dissolved molecules via vesicles.
9. If useful products are released from the cell, the process is called:
a. Secretion b. Excretion c. Sweating d. Urination
✅ Correct Answer: a. Secretion
Explanation: Secretion is the release of useful substances (like enzymes or hormones) produced by the cell, whereas excretion is the removal of waste products.
10. Neural excitability is not affected by:
a. Alkalosis b. Acidosis c. Neutral d. None of them
✅ Correct Answer: c. Neutral
Explanation: A neutral pH (physiological normal) maintains stability. Alkalosis increases neuronal excitability (causing spasms), while acidosis depresses it (causing coma).
11. Inhibitory transmitters may be: a. Glycine b. GABA c. Both d. None of them
✅ Correct Answer: c. Both
Explanation: GABA is the primary inhibitory neurotransmitter in the brain, while Glycine is the primary inhibitory neurotransmitter in the spinal cord.
12. Action potential in nerve fibers differ in:
a. Magnitude b. Duration c. Both d. None of them
✅ Correct Answer: c. Both
Explanation: Different types of nerve fibers (Type A, B, and C) have action potentials that vary in both magnitude (amplitude) and duration based on their diameter and myelination.
13. Homeostasis is controlled by regulating the activity of:
a. Cardiac muscle b. Smooth muscle c. Gland d. All
✅ Correct Answer: d. All
Explanation: Homeostasis is largely maintained by the Autonomic Nervous System, which regulates cardiac muscle, smooth muscle, and glands.
14. Hygrometer is used to measure the: a. Water content b. Protein contents c. Lipid contents d. Mineral contents
✅ Correct Answer: a. Water content
Explanation: A hygrometer is an instrument used to measure the amount of water vapor (humidity) in the air or a gas.
15. What percent solution of NaCl is considered isotonic to mammalian RBCs?
a. 0.8% b. 0.85% c. 0.90% d. 0.95%
✅ Correct Answer: c. 0.90%
Explanation: A 0.9% NaCl solution (Normal Saline) has the same osmotic pressure as mammalian blood plasma, preventing red blood cells from shrinking or bursting.
16. If a bathing fluid has a lower osmotic pressure than the cell, it is called:
a. Isotonic b. Hypotonic c. Hypertonic d. All
✅ Correct Answer: b. Hypotonic
Explanation: “Hypo-” means under or less. A hypotonic solution has a lower concentration of solutes (and higher water potential) than the cell interior.
17. If a bathing fluid has higher osmotic pressure than the cell it is called:
a. Isotonic b. Hypotonic c. Hypertonic d. All
✅ Correct Answer: c. Hypertonic
Explanation: “Hyper-” means over or more. A hypertonic solution has a higher concentration of solutes than the cell, causing water to leave the cell.
18. The property of being able to react to a stimulus is called:
a. Conductivity b. Irritability c. Contractility d. Transmission
✅ Correct Answer: b. Irritability
Explanation: Irritability (or excitability) is the inherent ability of living protoplasm to respond to environmental changes (stimuli).
19. Which ion is found in greater concentration inside the cell?
a. K b. Na c. Cl d. HCO3
✅ Correct Answer: a. K (Potassium)
Explanation: Potassium (K+) is the major intracellular cation, whereas Sodium (Na+) and Chloride (Cl-) are found in higher concentrations outside the cell.
20. Rough endoplasmic reticulum is involved in the synthesis of:
a. Glycogen b. Protein c. Steroids d. Lipids
✅ Correct Answer: b. Protein
Explanation: The “Rough” appearance is due to ribosomes attached to the surface, which are the sites of protein synthesis.
21. Metabolic water is the water generated in all cell of the body by:
a. Ribosome b. Mitochondria c. Golgi bodies d. Centrosome
✅ Correct Answer: b. Mitochondria
Explanation: Metabolic water is produced as a byproduct of cellular respiration (the electron transport chain), which takes place within the mitochondria.
22. The second largest constituent of protoplasm is:
a. Water b. Proteins c. Lipids d. Inorganics
✅ Correct Answer: b. Proteins
Explanation: Water is the most abundant constituent (70-85%), followed by proteins (10-20%), which form the structural and functional machinery of the cell.
23. Some proteins serve as structural element in:
a. Hair b. Wool c. Horn d. All of them
✅ Correct Answer: d. All of them
Explanation: These structures are primarily composed of Keratin, a fibrous structural protein that provides toughness and protection.
24. Cell physiology includes application of most of laws of which subjects?
a. Biology b. Chemistry c. Physics and Chemistry d. Physics
✅ Correct Answer: c. Physics and Chemistry
Explanation: Cell function relies on physical laws (diffusion, osmosis, electrical potentials) and chemical laws (enzymatic reactions, metabolism).
25. Which protein represent about 30% of the total protein content of the animal body? a. Collagens b. Elastins c. Keratins d. Fibrin
✅ Correct Answer: a. Collagens Explanation: Collagen is the most abundant protein in mammals, making up about 30% of total body protein. It is the main component of connective tissues.