Question 1

Which of the following best explains how traits are transmitted from parents to offspring in sexually reproducing organisms?

Accepted Answer

Traits are transmitted by inheriting chromosomes that carry genes from both parents.

Question 2

Which of the following statements correctly distinguishes between asexual and sexual reproduction?

Accepted Answer

Asexual reproduction produces genetically identical offspring, while sexual reproduction increases genetic variation among offspring.

Question 3

Which of the following correctly distinguishes between somatic cells and gametes in humans?

Accepted Answer

Somatic cells are diploid ($$2n$$), containing two sets of chromosomes, while gametes are haploid ($$n$$), containing one set of chromosomes.

Question 4

Which of the following best describes the difference between autosomes and sex chromosomes in humans?

Accepted Answer

Autosomes are chromosomes not directly involved in determining sex, while sex chromosomes (X and Y) determine an individual's sex.

Question 5

Which cells in the human body are diploid and which are haploid?

Accepted Answer

Somatic cells are diploid ($$2n$$), while gametes (sperm and egg cells) are haploid ($$n).$$

Question 6

Which of the following lists the correct sequence of phases in meiosis I?

Accepted Answer

Prophase I, Metaphase I, Anaphase I, Telophase I, Cytokinesis

Question 7

During which phase of meiosis does synapsis and crossing over occur, and what is the significance of this process?

Accepted Answer

Synapsis and crossing over occur during Prophase I, resulting in genetic recombination and increased genetic variation.

Question 8

Which of the following events occurs during meiosis I but not during mitosis?

Accepted Answer

Pairing of homologous chromosomes (synapsis) and crossing over

Question 9

How does independent assortment during meiosis contribute to genetic variation?

Accepted Answer

It results in the random distribution of maternal and paternal chromosomes to gametes, producing many possible combinations.

Question 10

Why is heritable variation crucial to Darwin’s theory of evolution by natural selection?

Accepted Answer

Heritable variation provides the raw material for natural selection to act upon, enabling populations to evolve over generations.

Question 11

A human cell with 46 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

23 chromosomes

Question 12

Which of the following best describes random fertilization and its impact on genetic variation?

Accepted Answer

Random fertilization increases genetic variation by combining any sperm with any egg, each with unique genetic combinations.

Question 13

Which of the following is NOT a source of genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during interphase

Question 14

If a diploid organism has a total of $$2n = 8$$ chromosomes, how many possible combinations of chromosomes can be produced in its gametes due to independent assortment alone?

Accepted Answer

$$2^4 = 16$

Question 15

Which of the following scenarios best illustrates the evolutionary advantage of sexual reproduction over asexual reproduction?

Accepted Answer

A population of fish produces genetically diverse offspring, some of which survive a sudden change in water temperature.

Question 16

Which process ensures that homologous chromosomes are separated into different cells during meiosis?

Accepted Answer

Anaphase I

Question 17

A geneticist observes that two genes are frequently inherited together. Which event during meiosis could explain why these genes sometimes appear in new combinations in offspring?

Accepted Answer

Crossing over during prophase I

Question 18

Which of the following statements about meiosis II is correct?

Accepted Answer

Meiosis II separates sister chromatids, similar to mitosis.

Question 19

Which of the following best explains why siblings from the same parents can look very different from each other?

Accepted Answer

Genetic variation from independent assortment, crossing over, and random fertilization leads to unique combinations of genes in each sibling.

Study Guidance for Meiosis & Sexual Life Cycles (Biology)

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