Question 1

Which of the following best explains why offspring produced by sexual reproduction are genetically different from their parents?

Accepted Answer

Offspring inherit unique combinations of genes due to independent assortment, crossing over, and random fertilization.

Question 2

In humans, how many possible combinations of chromosomes can result from independent assortment during gamete formation? Use $$n = 23$$ for the haploid number.

Accepted Answer

$$2^{23}$$, which is over 8 million combinations

Question 3

Which process is responsible for the exchange of genetic material between homologous chromosomes during meiosis?

Accepted Answer

Crossing over

Question 4

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

Accepted Answer

4

Question 5

Which of the following events occurs only during meiosis and not mitosis?

Accepted Answer

Pairing of homologous chromosomes and crossing over

Question 6

In the life cycle of plants, what is the name of the multicellular haploid stage that produces gametes by mitosis?

Accepted Answer

Gametophyte

Question 7

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry genes controlling the same inherited characters but may have different alleles.

Question 8

If a mutation occurs in a gene during gamete formation, what is the most likely consequence for the next generation?

Accepted Answer

The mutation will be present in all somatic cells of the offspring.

Question 9

Which of the following best describes the difference between asexual and sexual reproduction?

Accepted Answer

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

Question 10

During which phase of meiosis do homologous chromosomes separate and move toward opposite poles?

Accepted Answer

Anaphase I

Question 11

Which mechanism does NOT contribute to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during S phase

Question 12

A researcher observes a cell with two sets of chromosomes, each consisting of two sister chromatids, aligned at the metaphase plate. Which stage is this cell most likely in?

Accepted Answer

Metaphase I of meiosis

Question 13

Which of the following is a direct result of crossing over during meiosis?

Accepted Answer

Formation of recombinant chromosomes

Question 14

In which type of organism is the only diploid stage the single-celled zygote, with no multicellular diploid stage?

Accepted Answer

Most fungi and some protists

Question 15

Which of the following equations correctly represents the number of possible chromosome combinations due to independent assortment in a species with haploid number $$n$$?

Accepted Answer

$$2^n$$

Question 16

A geneticist is studying a plant species with a diploid number of 12. After meiosis, how many chromosomes will each gamete contain?

Accepted Answer

6

Question 17

Which of the following is NOT a unique event to meiosis I?

Accepted Answer

Separation of sister chromatids

Question 18

Why is sexual reproduction considered advantageous in changing environments?

Accepted Answer

It increases genetic variation, allowing populations to adapt to new environmental challenges.

Question 19

Which of the following best describes the evolutionary significance of genetic variation produced by sexual life cycles?

Accepted Answer

It allows populations to accumulate genetic variations favored by the environment through natural selection.

Question 20

A certain fungus reproduces only asexually. Which of the following is a likely consequence for its population?

Accepted Answer

Low genetic diversity, making the population more vulnerable to environmental changes

Meiosis and Sexual Life Cycles: Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard