Question 1

Which of the following best describes the main difference between asexual and sexual reproduction in multicellular organisms?

Accepted Answer

Asexual reproduction produces genetically identical offspring, while sexual reproduction produces genetically varied offspring.

Question 2

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

Accepted Answer

S phase

Question 3

A human cell with 46 chromosomes undergoes mitosis. How many chromosomes will each daughter cell have after division?

Accepted Answer

$$46$$

Question 4

Which event occurs during prophase of mitosis?

Accepted Answer

Chromatin condenses and spindle microtubules begin to form.

Question 5

What is the role of checkpoints in the cell cycle?

Accepted Answer

They regulate progression through the cell cycle and can halt division if conditions are unfavorable.

Question 6

Which of the following best explains why crossing over during meiosis increases genetic diversity?

Accepted Answer

It results in recombinant chromosomes with new combinations of maternal and paternal genes.

Question 7

A karyotype is useful for which of the following purposes?

Accepted Answer

Identifying chromosomal abnormalities such as extra or missing chromosomes.

Question 8

If a cell fails to pass the G1 checkpoint, what is the most likely outcome?

Accepted Answer

The cell will exit the cell cycle and enter the G0 phase.

Question 9

Which of the following equations correctly represents the number of possible chromosome combinations due to independent assortment in human gametes?

Accepted Answer

$$2^{23}$$

Question 10

A patient is diagnosed with Down syndrome. Which chromosomal abnormality is most likely present?

Accepted Answer

Trisomy 21, with three copies of chromosome 21.

Question 11

Which process reduces the chromosome number from diploid to haploid in the human life cycle?

Accepted Answer

Meiosis

Question 12

During which stage of meiosis do homologous chromosomes separate?

Accepted Answer

Anaphase I

Question 13

Which of the following is a direct result of nondisjunction during meiosis?

Accepted Answer

Some gametes have an abnormal number of chromosomes, such as $$n+1 or$$ $$n-1.$$

Question 14

Which of the following best describes the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces two identical diploid cells, while meiosis produces four genetically unique haploid cells.

Question 15

Which checkpoint ensures that all chromosomes are properly attached to the spindle before the cell proceeds with division?

Accepted Answer

M checkpoint

Question 16

A mutation causes a cell to ignore the G1 checkpoint. What is a possible consequence?

Accepted Answer

The cell may divide uncontrollably, potentially leading to cancer.

Question 17

Which of the following events occurs during metaphase of mitosis?

Accepted Answer

Chromosomes align at the cell's equator.

Question 18

Which of the following best explains why independent assortment and crossing over are important for evolution?

Accepted Answer

They increase genetic variation in offspring, providing material for natural selection.

Question 19

If a cell with a diploid number of 8 undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 20

Which of the following is NOT a function of mitosis in multicellular organisms?

Accepted Answer

Production of gametes

The Cellular Basis of Reproduction and Inheritance

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