Question 71
What is the outcome of a single mitotic division?
A) Two diploid cells
B) Four haploid cells
C) One diploid cell
D) Two haploid cells
Answer: A) Two diploid cells
Explanation: A single mitotic division produces two genetically identical diploid daughter cells.
Question 72
What occurs during prophase I of meiosis that does not occur in mitosis?
A) Chromosome condensation
B) Nuclear envelope breakdown
C) Crossing over
D) Spindle formation
Answer: C) Crossing over
Explanation: Crossing over occurs during prophase I of meiosis, allowing genetic material exchange between homologous chromosomes, a feature not present in mitosis.
Question 73
What is the role of the checkpoints in the cell cycle?
A) To accelerate cell division
B) To ensure that each phase is completed accurately
C) To replicate DNA
D) To assist in chromatin condensation
Answer: B) To ensure that each phase is completed accurately
Explanation: Checkpoints monitor the cell cycle progression and ensure each phase is completed correctly before moving to the next.
Question 74
Which of the following phases is part of interphase?
A) M Phase
B) Cytokinesis
C) G2 Phase
D) Anaphase
Answer: C) G2 Phase
Explanation: Interphase includes the G1, S, and G2 phases, during which the cell grows and prepares for division.
Question 75
What is a characteristic of prokaryotic cell division?
A) It occurs through mitosis.
B) It involves meiosis.
C) It occurs by binary fission.
D) It requires a spindle apparatus.
Answer: C) It occurs by binary fission.
Explanation: Prokaryotic cells divide through binary fission, a simple and rapid process without mitosis or meiosis.
Question 76
What is the significance of checkpoints in the cell cycle?
A) They allow rapid cell division.
B) They ensure cells do not divide with damaged DNA.
C) They promote tumor formation.
D) They initiate apoptosis only.
Answer: B) They ensure cells do not divide with damaged DNA.
Explanation: Checkpoints play a critical role in preventing the division of cells with damaged or incomplete DNA, thus maintaining genomic integrity.
Question 77
What happens to a cell if it fails the G1 checkpoint?
A) It proceeds to S phase.
B) It enters the G0 phase.
C) It undergoes apoptosis.
D) It immediately divides.
Answer: B) It enters the G0 phase.
Explanation: If a cell does not meet the requirements at the G1 checkpoint, it may enter the G0 phase, a state of dormancy where it does not divide.
Question 78
Which of the following occurs during metaphase II?
A) Homologous chromosomes separate.
B) Chromosomes line up at the equator.
C) Sister chromatids are pulled apart.
D) The nuclear envelope re-forms.
Answer: B) Chromosomes line up at the equator.
Explanation: During metaphase II, individual chromosomes line up along the cell’s equatorial plane in preparation for separation.
Question 79
Which protein complex is essential for the formation of the mitotic spindle?
A) Kinetochore
B) Centromere
C) Centrioles
D) Chromatin
Answer: C) Centrioles
Explanation: Centrioles are essential for the formation of the mitotic spindle, which is responsible for chromosome movement during cell division.
Question 80
What is the role of ligase during DNA replication?
A) To synthesize RNA primers
B) To unwind the DNA double helix
C) To seal gaps between Okazaki fragments
D) To synthesize new DNA strands
Answer: C) To seal gaps between Okazaki fragments
Explanation: Ligase is responsible for sealing the nicks between Okazaki fragments on the lagging strand during DNA replication.
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