All Free Biology MCQs with Answers

• A. Phagocytosis
• B. Endocytosis
• C. Pinocytosis
• D. Exocytosis

Explanation: The ingestion of liquid material into a cell by the budding of small vesicles from the cell membrane is called pinocytosis while the process by which certain living cells called phagocytes ingest or engulf other cells or solid particles.

• A. Mitochondria
• B. Centrioles
• C. Ribosomes
• D. Lysosomes

Explanation: Spindle fibers are made up of microtubules. There are two centrioles in the non-dividing stage of a cell. Each centriole has nine microtubule triplets. During the dividing stage of cell spindle fibers arise from these centrioles

• A. Outer membrane
• B. Outer compartment
• C. Inner membrane
• D. Inner compartment

Explanation: Mitochondria is a double membrane bound cell organelle. The inner membrane have folding known as cristae which are studded with large number of globular particles which are called as F1 particles.

• A. Ten
• B. Eight
• C. Nine
• D. Seven

Explanation: Each centriole is made of nine microtubule triplets (9x3 = 27).

• A. Galactose
• B. Glucose
• C. Phospholipids
• D. Carbohydrate

Explanation: Fluid mosaic model of the plasma membrane described the arrangement of phospholipids in two layers, stabilized interiorly by the hydrophobic interactions while hydrophilic interactions at intracellular and extracellular faces with embedded proteins randomly.

• A. Passive Diffusion
• B. Active Transport
• C. Endocytosis
• D. Facilitated Diffusion

Explanation: Facilitated diffusion also known as facilitated transport or passive-mediated transport, is the process of spontaneous passive transport of molecules or ions across a biological membrane via specific trans-membrane integral proteins.

• A. Ribosomes
• B. Mitochondria
• C. Polysomes
• D. Golgi bodies

Explanation: Mesosomes are membrane infoldings in bacterial cells and are more prominent in Gram negative bacteria. Mesosomes are the sites of cellular respiration. Electron transport chain occurs in mesosomes as mitochondria is absent in bacteria.

• A. Single, circular, double stranded molecule not bound by membrane
• B. Double circular molecule
• C. Linear, double stranded molecule
• D. Single, circular, double stranded and membrane bound

Explanation: Genomic DNA molecules in prokaryotes are single circular, double stranded and not bounded by any membrane and it is freely dispersed in cytoplasm.

• A. Golgi body
• B. Mitochondria
• C. Ribosome
• D. Plastid

Explanation: A ribosome is made up of two sub-units, larger and smaller subunits. In case of eukaryotic cells, larger subunit is 60s and smaller subunit is 40s while prokaryotic cells have 50s and 30s larger and smaller subunits, respectively.

• A. Phagocytosis
• B. Pinocytosis
• C. Autophagy
• D. Exocytosis

Explanation: Autophagy is the natural, regulated mechanism of the cell that removes unnecessary or dysfunctional components. It allows the orderly degradation and recycling of cellular components with the help of lysosomes.