Q11. Chloroplasts are vital for photosynthesis in plant cells because they contain
a) Ribosomes
b) Chlorophyll
c) Lysosomes
d) Mitochondria
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Correct Answer: b) Chlorophyll
Explanation: Chloroplasts are critical for photosynthesis in plant cells due to the presence of chlorophyll, a green pigment that captures light energy. This energy is then used to convert carbon dioxide and water into glucose, a process fundamental to plant growth and oxygen production.
Q12. What type of endocytosis involves the ingestion of liquid into a cell by the budding of small vesicles from the cell membrane?
a) Phagocytosis
b) Exocytosis
c) Pinocytosis
d) Osmosis
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Correct Answer: c) Pinocytosis
Explanation: Pinocytosis, often described as ‘cell drinking’, involves the ingestion of liquid into a cell through the formation of small vesicles. This form of endocytosis allows the cell to sample and absorb extracellular fluid and its dissolved solutes.
Q13. Which of these structures is responsible for modifying, sorting, and packaging proteins and lipids?
a) Golgi apparatus
b) Ribosomes
c) Nucleus
d) Mitochondria
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Correct Answer: a) Golgi apparatus
Explanation: The Golgi apparatus plays a crucial role in modifying, sorting, and packaging proteins and lipids received from the endoplasmic reticulum. It prepares these substances for either secretion outside the cell or for use within the cell.
Q14. The network of protein filaments providing support and shape to a cell is called the
a) Cytoskeleton
b) Cytoplasm
c) Cell membrane
d) Nuclear membrane
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Correct Answer: a) Cytoskeleton
Explanation: The cytoskeleton, a network of protein filaments, is essential in maintaining the cell’s shape and structural integrity. It is also involved in cell movement, division, and the transport of materials within the cell.
Q15. The process of cells taking in molecules by forming new vesicles from the plasma membrane is known as
a) Endocytosis
b) Exocytosis
c) Phagocytosis
d) Osmosis
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Correct Answer: a) Endocytosis
Explanation: Endocytosis is a cellular process where cells absorb molecules by engulfing them. This involves the plasma membrane folding inward to form new vesicles containing the ingested substances.
Q16. What is the primary role of messenger RNA (mRNA) in the cell?
a) DNA replication
b) Carrying amino acids to ribosomes
c) Transferring genetic information from DNA to ribosomes
d) Producing energy
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Correct Answer: c) Transferring genetic information from DNA to ribosomes
Explanation: Messenger RNA (mRNA) plays a key role in transferring genetic information from DNA in the nucleus to the ribosomes in the cytoplasm. It acts as a template for protein synthesis, ensuring the correct sequence of amino acids is assembled.
Q17. The jelly-like substance within a cell that holds various organelles and is the site of numerous chemical reactions is
a) Cytoplasm
b) Nucleoplasm
c) Extracellular matrix
d) Plasma membrane
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Correct Answer: a) Cytoplasm
Explanation: The cytoplasm is a jelly-like substance that fills the interior of the cell, holding various organelles. It is the site of many cellular processes and chemical reactions and helps to maintain cell structure.
Q18. During which phase of mitosis do the chromosomes separate and move to opposite poles of the cell?
a) Prophase
b) Metaphase
c) Anaphase
d) Telophase
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Correct Answer: c) Anaphase
Explanation: During anaphase, the chromosomes, previously aligned at the cell’s equator, separate and move to opposite poles of the cell. This ensures that each daughter cell will receive an identical set of chromosomes.
Q19. In eukaryotic cells, the synthesis of proteins occurs
a) Inside the nucleus
b) On the surface of the endoplasmic reticulum
c) Within lysosomes
d) On the plasma membrane
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Correct Answer: b) On the surface of the endoplasmic reticulum
Explanation: In eukaryotic cells, protein synthesis primarily occurs on the surface of the rough endoplasmic reticulum. This is where ribosomes are attached, facilitating the translation of RNA into proteins.
Q20. The principal energy currency of the cell is
a) Glucose
b) DNA
c) ATP
d) Fatty acids
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Correct Answer: c) ATP
Explanation: ATP (adenosine triphosphate) is the principal energy currency of the cell. It provides energy for many biochemical cellular processes by undergoing enzymatic hydrolysis, which releases energy.