Question 1

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

Accepted Answer

Asexual reproduction produces genetically identical offspring from a single parent, while sexual reproduction produces genetically diverse offspring 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, Gamete: 23

Question 3

Which event is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 4

During which phase of meiosis does crossing over occur, and what is the significance of this event?

Accepted Answer

Prophase I; it increases genetic variation among offspring

Question 5

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

Accepted Answer

$$4$$

Question 6

Which mechanism contributes most directly to the genetic variation observed in sexually reproducing populations?

Accepted Answer

Independent assortment of chromosomes during meiosis

Question 7

What is the formula for the number of possible chromosome combinations due to independent assortment in gametes, and what is the value for humans?

Accepted Answer

$$2^n$$; for humans, $$2^{23}$$

Question 8

Which of the following best explains why meiosis and fertilization must alternate in sexual life cycles?

Accepted Answer

To maintain a constant chromosome number across generations

Question 9

A karyotype is used in medical genetics to:

Accepted Answer

Display the ordered pairs of chromosomes from a cell to identify chromosomal abnormalities

Question 10

Which life cycle pattern is characteristic of most fungi and some protists, and what is its key feature?

Accepted Answer

Haploid-dominant; the zygote is the only diploid stage

Question 11

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry genes controlling the same inherited characters

Question 12

During meiosis II, what is the main event that occurs?

Accepted Answer

Sister chromatids separate

Question 13

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

Accepted Answer

Formation of recombinant chromosomes

Question 14

Why was heritable variation crucial to Darwin’s theory of evolution?

Accepted Answer

It provided the raw material for natural selection to act upon

Question 15

Which of the following best describes the role of mutations in genetic variation?

Accepted Answer

Mutations are the original source of different alleles

Question 16

In a plant exhibiting alternation of generations, which cells undergo meiosis to produce spores?

Accepted Answer

Sporophyte cells

Question 17

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

Accepted Answer

Replication of chromosomes during mitosis

Question 18

A human sperm cell contains:

Accepted Answer

22 autosomes and either an X or Y chromosome

Question 19

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

Accepted Answer

Diploid cells have two sets of chromosomes, allowing homologous pairs to form and separate

Question 20

If a mutation occurs in a gene located on an autosome, which cells will be affected in the next generation?

Accepted Answer

All cells derived from the zygote, including somatic and gamete cells

Meiosis and Sexual Life Cycles: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard