Question 1

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

Accepted Answer

Because homologous chromosomes pair and undergo crossing over during prophase I.

Question 2

During which stage of meiosis do homologous chromosomes separate, reducing the chromosome number by half?

Accepted Answer

Anaphase I

Question 3

A cell with genotype AaBb undergoes meiosis. According to the law of independent assortment, what is the expected ratio of gamete types produced?

Accepted Answer

$$1\!:\!1\!:\!1\!:\!1$$ for AB, Ab, aB, ab

Question 4

Which protein complex is essential for the tight pairing of homologous chromosomes during prophase I of meiosis?

Accepted Answer

Synaptonemal complex

Question 5

What is the primary outcome of crossing over during meiosis?

Accepted Answer

It increases genetic diversity by exchanging DNA between nonsister chromatids.

Question 6

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

Accepted Answer

Separation of sister chromatids

Question 7

If a diploid cell with $$2n = 8$$ chromosomes undergoes meiosis, how many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 8

Which stage of meiosis is most directly responsible for Mendel’s law of segregation?

Accepted Answer

Anaphase I

Question 9

A mutation disrupts the function of cohesin proteins during meiosis. What is the most likely consequence?

Accepted Answer

Sister chromatids separate prematurely during meiosis I.

Question 10

Which of the following best describes the difference between mitosis and meiosis in terms of genetic outcomes?

Accepted Answer

Mitosis produces two genetically identical cells, while meiosis produces four genetically distinct cells.

Question 11

In which substage of prophase I do recombination nodules first become visible, indicating the sites of crossing over?

Accepted Answer

Pachytene

Question 12

A geneticist observes that in a certain organism, gametes are produced that are not in a 1:1:1:1 ratio for two genes. Which meiotic process is most likely disrupted?

Accepted Answer

Independent assortment

Question 13

Which of the following is a direct result of the dissolution of the synaptonemal complex during diplotene?

Accepted Answer

Homologous chromosomes are held together only at chiasmata.

Question 14

If nondisjunction occurs during meiosis I, what is the expected chromosomal composition of the resulting gametes?

Accepted Answer

Half will have an extra chromosome, half will be missing one.

Question 15

Which event marks the completion of crossing over during meiosis?

Accepted Answer

Dissolution of chiasmata during metaphase I

Question 16

A patient is diagnosed with a genetic disorder caused by the inheritance of an extra chromosome. This most likely resulted from which meiotic error?

Accepted Answer

Nondisjunction during anaphase I or II

Question 17

Which of the following best describes the role of kinetochore microtubules during meiosis?

Accepted Answer

They pull homologous chromosomes or sister chromatids toward opposite poles.

Question 18

Why is meiosis I referred to as the 'reduction division'?

Accepted Answer

Because the chromosome number is reduced from diploid to haploid.

Question 19

Which of the following is NOT a characteristic of asexual reproduction?

Accepted Answer

Gametes are produced by meiosis.

Question 20

In a human cell, how many genetically distinct gametes can be produced due to independent assortment alone, assuming $$n = 23$$?

Accepted Answer

$$2^{23}$$

Cell Division and Chromosome Heredity: Meiosis and Mendelian Principles

Guida di studio - Domande di pratica

Study guide - Flashcard