Question 1

Which of the following best describes the outcome of mitosis in a human somatic cell?

Accepted Answer

Two daughter cells, each with $$2n$$ chromosomes

Question 2

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 3

A mutation in a gene encoding a cyclin-dependent kinase (Cdk) that prevents its activation would most likely result in:

Accepted Answer

Cell cycle arrest at a checkpoint

Question 4

Which of the following events is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Pairing of homologous chromosomes and crossing over

Question 5

A cell with genotype GgDd undergoes meiosis. Assuming independent assortment and no crossing over, what is the expected ratio of gamete genotypes produced?

Accepted Answer

1:1:1:1 for GD, Gd, gD, gd

Question 6

Which checkpoint ensures that all chromosomes are properly attached to the spindle before anaphase begins?

Accepted Answer

Metaphase checkpoint

Question 7

In mammals, what is the default pathway of sexual differentiation in the absence of SRY gene expression?

Accepted Answer

Development of ovaries (female)

Question 8

Which of the following statements about the pseudoautosomal regions (PARs) of the X and Y chromosomes is correct?

Accepted Answer

PARs allow pairing and recombination between X and Y chromosomes during meiosis

Question 9

A patient is found to have an XXY karyotype. Which of the following is most likely true?

Accepted Answer

The individual will develop as a male due to the presence of SRY

Question 10

Which of the following best explains why gametes produced by meiosis are genetically diverse?

Accepted Answer

Crossing over and independent assortment during meiosis I

Question 11

If a somatic cell in G$$_2$$ phase contains 46 chromosomes, how many chromatids does it contain?

Accepted Answer

$$92$$

Question 12

Which of the following is NOT a characteristic feature of the G$$_1$$ phase of the cell cycle?

Accepted Answer

High rates of DNA replication

Question 13

A mutation causes a cell to bypass the metaphase checkpoint. What is a likely consequence?

Accepted Answer

Chromosomes may not be properly segregated, leading to aneuploidy

Question 14

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

Accepted Answer

They activate cyclin-dependent kinases (Cdks) to regulate cell cycle progression

Question 15

Which of the following is true regarding the chromosome number after meiosis II in humans?

Accepted Answer

Each cell has $$n$$ chromosomes

Question 16

A cell is observed to have two centrosomes at opposite poles and chromosomes aligned at the center. Which stage is this?

Accepted Answer

Metaphase

Question 17

Which of the following is a direct result of independent assortment during meiosis?

Accepted Answer

Each gamete receives a random mix of maternal and paternal chromosomes

Question 18

A neuron is a highly specialized cell that does not divide. In which phase of the cell cycle is it most likely to be found?

Accepted Answer

G$$_0$$ phase

Question 19

Which of the following best explains why cancer cells often have abnormal chromosome numbers?

Accepted Answer

They bypass cell cycle checkpoints, leading to improper chromosome segregation

Question 20

Which of the following is the correct sequence of events in meiosis I?

Accepted Answer

Pairing of homologous chromosomes, crossing over, segregation of homologs

Cell Division and Chromosomal Heredity: Essentials for Genetics

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