All Free Biology MCQs with Answers

• A. Convex, maturing face
• B. Concave, forming face
• C. Convex, forming face
• D. Concave, maturing face

Explanation: The trans face of golgi apparatus (concave surface) where the cisternae breaks up to form new vesicles is also known as the maturing face.

• A. Primary wall
• B. Secondary wall
• C. Middle lamella
• D. Both A and B

Explanation: Cellulose gives strength and rigidity to the cell. It makes the wall of plant cells.a) Primary wall - It is composed of the polysaccharides cellulose, hemicelluloses and pectin.b) Secondary wall - The main components of secondary walls are cellulose, xylan, glucomannan and lignin. However, secondary cell wall contains more cellulose than primary cell wall.c) Middle lamella - It is mainly composed of pectins.

• A. Tonoplast
• B. Protoplast
• C. Symplast
• D. Epiblast

Explanation: A vacuole membrane is called the tonoplast. The symplast pathway is the movement of water molecules between cytoplasm, plasma membrane, and plasmodesmata. Epiblast is the outermost layer of an embryo. Hence the answer is protoplast, Option B.

• A. Cytoplasm
• B. Ribosomes
• C. Flagella
• D. Peptidoglycan cell wall

Explanation: Option (d) suggests that the presence of a peptidoglycan cell wall would confirm that the cell is prokaryotic. This statement is correct. The presence of a peptidoglycan cell wall is a characteristic feature of prokaryotic cells, specifically bacteria. Prokaryotic cells have a rigid cell wall made of peptidoglycan, which provides structural support and protection to the cell. On the other hand, eukaryotic cells do not have a peptidoglycan cell wall.

• A. Plasma membrane
• B. Cell wall
• C. Desmosomes
• D. Plasmodesmata

Explanation: Correct option is C. Animal cells are interconnected by desmosomes. A desmosome or macula adherens can be defined as a specialized cellular structure which helps in cell-to-cell adhesion. It is formed from protein plaques which are present in the cell membranes and are linked by filaments. They are found in animal cells which act like welds between adjacent epithelial cells and connect them. So, the correct answer is Desmosomes.

• A. Lysosomes
• B. Ribosomes
• C. Endoplasmic reticulum
• D. Cell membrane

Explanation: In the question, you need to identify the structure that serves as a base of attachment for the cytoskeleton in some organisms, which is the cell membrane. the cell membrane can serve as a base of attachment for the cytoskeleton. The cytoskeleton, composed of protein filaments, can anchor to specific proteins within the cell membrane, providing structural support and facilitating cellular movements. Hence, option D is the correct answer.

• A. Carbohydrates
• B. Phospholipids
• C. Cell wall
• D. Proteins

Explanation: The plasma membrane is made up of two layers of phospholipids, and hence called lipid-bilayer. The non-polar tails of both phospholipids face each other while the heads face towards the cytoplasm and extracellular space.

• A. Both hydrophilic and hydrophobic
• B. Hydrophobic
• C. None of these
• D. Hydrophilic

Explanation: The head of the phospholipid in the lipid bilayer of the plasma membrane is hydrophilic (water-loving), while the tail is hydrophobic (water-hating).

• A. Polar side
• B. None of these
• C. Non-polar side
• D. Both of these

Explanation: In the plasma membrane, the fatty acid is always attached at the non-polar end. The two non-polar ends of the double-layered membrane face each other while the polar ends face the cytoplasm and extracellular space.

• A. Mitochondria
• B. Lysosomes
• C. Chloroplast
• D. Cell membrane

Explanation: Widespread damage to mitochondria causes cells to die because of insufficient energy production. In fact, damaged mitochondria may also secrete enzymes that may accelerate the process of cell death. Lysosomes are responsible for normal, physiologic cell death. Lysosomal dysfunction mainly leads to lysosomal storage diseases.