Question 1

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

Accepted Answer

Because meiosis and fertilization shuffle alleles, resulting in unique combinations of genes.

Question 2

A human somatic cell contains 46 chromosomes. How many chromosomes are present in a human gamete?

Accepted Answer

$$23$$

Question 3

Which process is responsible for reducing the chromosome number from diploid to haploid in sexually reproducing organisms?

Accepted Answer

Meiosis

Question 4

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

Accepted Answer

Anaphase I

Question 5

In plants exhibiting alternation of generations, which structure is diploid?

Accepted Answer

Sporophyte

Question 6

If an organism has a haploid number $$n = 4$$, how many possible combinations of chromosomes can result from independent assortment during meiosis?

Accepted Answer

$$2^4 = 16$

Question 7

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

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 8

A karyotype is useful for which of the following purposes?

Accepted Answer

Identifying the number and structure of chromosomes in a cell

Question 9

Which mechanism contributes most directly to the genetic variation seen in siblings (excluding identical twins)?

Accepted Answer

Crossing over during prophase I of meiosis

Question 10

In a certain fungus, the only diploid stage is the zygote. What process must occur immediately after zygote formation to restore the haploid state?

Accepted Answer

Meiosis

Question 11

Which of the following best describes the difference between homologous chromosomes and sister chromatids?

Accepted Answer

Sister chromatids are identical copies formed by DNA replication; homologous chromosomes are similar but not identical, each inherited from a different parent.

Question 12

Which of the following statements about asexual reproduction is correct?

Accepted Answer

It results in offspring that are genetically identical to the parent.

Question 13

A zygote is formed by the fusion of two gametes. If each gamete contains $$n$$ chromosomes, how many chromosomes will the zygote have?

Accepted Answer

$$2n$$

Question 14

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

Accepted Answer

Formation of recombinant chromosomes

Question 15

Why is sexual reproduction considered advantageous in changing environments?

Accepted Answer

It increases genetic variation, which can enhance survival under new environmental conditions.

Question 16

Which of the following equations correctly represents the number of possible chromosome combinations due to independent assortment in a gamete, where $$n is $$the haploid number?

Accepted Answer

$$2^n$$

Question 17

A couple is concerned about the risk of genetic disorders in their offspring. Which process during sexual reproduction is most likely to introduce new genetic combinations that could affect this risk?

Accepted Answer

Crossing over during meiosis

Question 18

Which of the following statements about the alternation of generations in plants is true?

Accepted Answer

The sporophyte is diploid and produces spores by meiosis.

Question 19

Which of the following is NOT a mechanism that contributes to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of chromosomes without mutation

Question 20

A geneticist is studying a population of animals that reproduce only asexually. Which of the following would she expect to find compared to a sexually reproducing population?

Accepted Answer

Lower genetic diversity because offspring are clones of the parent

Meiosis and Sexual Life Cycles: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard