Ch. 10 Meiosis + Sexual Life Cycles

Question 1

The synaptonemal complex __________.

Answer 1

physically connects homologous chromosomes during prophase I

Question 2

Spores and gametes differ in that __________.

Answer 2

gametes must fuse to form a zygote and continue development, but each spore can develop into an independent multicellular organisms on its own

Question 3

Which of the following occurs during anaphase II?

Answer 3

Sister chromatids separate and migrate toward opposite poles.

Question 4

In a male mammal, every germ cell that undergoes meiosis in the production of gametes gives rise to __________ sperm.

Answer 4

four

Question 5

Sister chromatids __________.

Answer 5

are identical copies of each other formed during DNA synthesis

Question 6

Crossing over occurs during __________.

Answer 6

prophase I

Question 7

Which of the following is included in alternation of generations?

Answer 7

All of the listed responses are correct.

Question 8

How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)?

Answer 8

16

Question 9

Homologous chromosomes move toward opposite poles of a dividing cell during __________.

Answer 9

meiosis I

Question 10

A karyotype is a __________.

Answer 10

photograph of all of an individual’s chromosomes

Question 11

Which of the following contributes to genetic variation in sexually reproducing species?

Answer 11

Independent assortment, crossing over, and random fertilization

Question 12

Human somatic cells contain __________ set(s) of chromosomes and are therefore termed __________.

Answer 12

two; diploid

Question 13

Fertilization produces a __________.

Answer 13

diploid zygote

Question 14

How many genes are present in the human genome?

Answer 14

Tens of thousands

Question 15

How many pairs of autosomes do humans have?

Answer 15

22

Question 16

Which of the following statements best describes the advantage that sexual reproduction likely provides over asexual reproduction?

Answer 16

Although energetically more costly than asexual reproduction, sexual reproduction leads to different combinations of alleles that could provide adaptability in a changing environment.

Question 17

In sexually reproducing species, the chromosome number remains stable over time because __________ and __________ always alternate.

Answer 17

meiosis; fertilization

Question 18

What is a locus?

Answer 18

The precise location of a gene on a chromosome

Question 19

Which event occurs only during prophase I of the first meiotic division?

Answer 19

Synapsis of homologous chromosomes occurs.

Question 20

In a diploid set of chromosomes, one member of each pair of homologous chromosomes is derived from the father (paternal) and the other comes from the mother (maternal). If 2n = 6, what is the probability of obtaining a gamete in which all the chromosomes are paternal ones?

Answer 20

⅛

Question 21

A human cell containing 22 autosomes and a Y chromosome is a __________.

Answer 21

sperm

Question 22

Synapsis occurs during __________.

Answer 22

prophase I