Question 1

Which of the following best describes the difference between asexual and sexual reproduction in terms of genetic variation?

Accepted Answer

Asexual reproduction results in offspring that are genetically identical to the parent, while sexual reproduction results in offspring with genetic variation due to the combination of genes from two parents.

Question 2

In humans, how many chromosomes are found in a somatic cell and how many in a gamete?

Accepted Answer

Somatic cell: 46 chromosomes; Gamete: 23 chromosomes

Question 3

What is the term for the specific location of a gene on a chromosome?

Accepted Answer

Locus

Question 4

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

Accepted Answer

Crossing over occurs during prophase I and contributes to genetic variation by exchanging DNA between homologous chromosomes.

Question 5

Which equation represents the number of possible chromosome combinations due to independent assortment in gametes, where $$n is $$the haploid number?

Accepted Answer

$$2^n$$

Question 6

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

Accepted Answer

4 chromosomes

Question 7

Which of the following events is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 8

In the alternation of generations life cycle seen in plants, which process produces haploid spores from a diploid sporophyte?

Accepted Answer

Meiosis

Question 9

If a mutation occurs in a gene, what is the immediate result at the genetic level?

Accepted Answer

A new allele is created.

Question 10

Which mechanism contributes most directly to the genetic variation observed in siblings from the same parents?

Accepted Answer

Independent assortment of chromosomes during meiosis

Question 11

A zygote is formed by the fusion of two gametes. If each gamete has $$n = 23$$ chromosomes, how many chromosomes does the zygote have?

Accepted Answer

46 chromosomes

Question 12

Which of the following best explains why only diploid cells can undergo meiosis?

Accepted Answer

Meiosis requires homologous chromosome pairs, which are only present in diploid cells.

Question 13

In a karyotype, what is the primary purpose of arranging chromosomes in pairs?

Accepted Answer

To observe homologous chromosomes and detect chromosomal abnormalities.

Question 14

Which of the following statements about gametes is correct?

Accepted Answer

Gametes contain a single set of chromosomes and are haploid.

Question 15

During meiosis II, what is the key event that distinguishes it from meiosis I?

Accepted Answer

Separation of sister chromatids

Question 16

Which process restores the diploid chromosome number in sexually reproducing organisms?

Accepted Answer

Fertilization

Question 17

A plant exhibits alternation of generations. Which stage is diploid and produces haploid spores?

Accepted Answer

Sporophyte

Question 18

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

Accepted Answer

Replication of DNA during mitosis

Question 19

If a human sperm cell carrying an X chromosome fertilizes an egg, what will be the sex chromosome composition of the resulting zygote?

Accepted Answer

XX

Question 20

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

Accepted Answer

It provides a basis for natural selection to act upon, leading to adaptation and evolution.

Meiosis and Sexual Life Cycles: Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard