Question 1

Which of the following best describes homologous chromosomes?

Accepted Answer

Two chromosomes that carry genes for the same set of hereditary characteristics, one inherited from each parent.

Question 2

During which phase of meiosis does crossing over occur, and what is its significance?

Accepted Answer

Crossing over occurs during prophase I and results in genetic recombination, increasing genetic variation.

Question 3

A diploid cell with $$2n = 8$$ undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 4

Which of the following events does NOT occur during meiosis I?

Accepted Answer

Separation of sister chromatids.

Question 5

If a species has 10 pairs of chromosomes, how many possible combinations of chromosomes can be produced in its gametes due to independent assortment alone? Use the formula $$2^n$$, where $$n is $$the number of chromosome pairs.

Accepted Answer

$$2^{10} = 1$$,024$$

Question 6

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

Accepted Answer

Genetic variation arises from crossing over and independent assortment during meiosis, as well as random fertilization.

Question 7

Which of the following statements about gametes is correct?

Accepted Answer

Gametes are haploid cells produced by meiosis.

Question 8

A mutation occurs in a gene on a paternal homologous chromosome during meiosis. Which process could result in this mutation being passed to a gamete that also contains genetic material from the maternal homolog?

Accepted Answer

Crossing over during prophase I.

Question 9

Which of the following is a key difference between meiosis and mitosis?

Accepted Answer

Meiosis produces four genetically different haploid cells, while mitosis produces two genetically identical diploid cells.

Question 10

A geneticist is studying a plant species in which the diploid number is $$2n = 12. $$After meiosis, how many chromosomes will be present in each spore?

Accepted Answer

$$6$$

Question 11

Which of the following scenarios best illustrates the concept of random fertilization as a source of genetic variation?

Accepted Answer

A single egg is fertilized by one of millions of genetically unique sperm, resulting in a unique zygote.

Question 12

During which stage of meiosis do homologous chromosomes separate and move to opposite poles of the cell?

Accepted Answer

Anaphase I

Question 13

If gametes were produced by mitosis instead of meiosis, what would be the result after fertilization in humans?

Accepted Answer

The zygote would have twice the normal number of chromosomes ($$4n$$ instead of $$2n).$$

Question 14

Which of the following best describes the outcome of meiosis II?

Accepted Answer

Sister chromatids are separated, resulting in four haploid cells each with unreplicated chromosomes.

Question 15

A woman is a carrier for a genetic disorder located on one of her homologous chromosomes. During meiosis, which process could result in her passing a recombinant chromosome to her child?

Accepted Answer

Crossing over during prophase I.

Question 16

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

Accepted Answer

Replication of DNA during S phase.

Question 17

In human females, meiosis results in the production of:

Accepted Answer

One large gamete (egg) and three small polar bodies.

Question 18

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

Accepted Answer

It reduces the chromosome number by half, ensuring that fertilization restores the diploid number.

Question 19

A cell with $$n = 5$$ undergoes meiosis. How many genetically unique gametes can be produced by independent assortment alone?

Accepted Answer

$$2^5 = 32$

Question 20

Which of the following is true regarding the difference between somatic cells and gametes?

Accepted Answer

Somatic cells are diploid, while gametes are haploid.

Chapter 10: Meiosis & Reproduction – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard