Question 1

Which of the following best describes the difference between homologous chromosomes and sister chromatids?

Accepted Answer

Homologous chromosomes are chromosomes of the same type inherited from each parent, while sister chromatids are identical copies formed during DNA replication.

Question 2

How many chromosomes are found in a human somatic cell and a human gamete, respectively?

Accepted Answer

46 in a somatic cell and 23 in a gamete

Question 3

Which checkpoint in the cell cycle is primarily responsible for ensuring that DNA is undamaged before replication proceeds?

Accepted Answer

G1 checkpoint

Question 4

During which phase of mitosis do sister chromatids separate and move toward opposite poles?

Accepted Answer

Anaphase

Question 5

What is the main difference between the life cycles of plants and fungi compared to animals?

Accepted Answer

Plants and fungi have a multicellular haploid stage, while animals do not.

Question 6

Which equation correctly represents the chromosome number after meiosis in humans?

Accepted Answer

$$n = 23$$

Question 7

Which process during meiosis contributes most directly to genetic variation in offspring?

Accepted Answer

Crossing over during prophase I

Question 8

A bacterial cell divides by binary fission. Which statement best describes how this process differs from mitosis in eukaryotic cells?

Accepted Answer

Binary fission does not involve the formation of a mitotic spindle.

Question 9

Which of the following is NOT a function of cell cycle checkpoints?

Accepted Answer

Initiating DNA replication in the absence of growth factors

Question 10

If a mutation disables the G2 checkpoint, what is the most likely consequence for the cell?

Accepted Answer

Cells may enter mitosis with damaged or unreplicated DNA

Question 11

Which of the following best explains why cancer cells often divide uncontrollably?

Accepted Answer

They bypass cell cycle checkpoints due to mutations in regulatory genes.

Question 12

Which phase of the cell cycle is characterized by DNA synthesis?

Accepted Answer

S phase

Question 13

Which of the following is a major growth factor that can stimulate cells to pass the G1 checkpoint?

Accepted Answer

Cyclin D

Question 14

Which equation represents the number of possible chromosome combinations due to independent assortment in a diploid organism with $$n$$ chromosome pairs?

Accepted Answer

$$2^n$$

Question 15

Which of the following events occurs only during meiosis and not mitosis?

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 16

A patient’s cells are observed to have nondisjunction during meiosis I. What is the most likely outcome for the gametes produced?

Accepted Answer

Some gametes will have an extra chromosome, and some will be missing a chromosome.

Question 17

Which of the following is NOT a source of genetic variation in sexual reproduction?

Accepted Answer

Replication of DNA

Question 18

Which statement best describes the role of cyclins in the cell cycle?

Accepted Answer

Cyclins regulate the progression of the cell cycle by activating cyclin-dependent kinases.

Question 19

Which of the following best explains why meiosis is essential for sexual reproduction?

Accepted Answer

It reduces the chromosome number by half, preventing chromosome doubling in offspring.

Question 20

Which phase of meiosis is most similar to mitosis in terms of chromosome behavior?

Accepted Answer

Meiosis II

Cell Cycle, Mitosis, and Sexual Life Cycles: Study Guide

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