Chapter 8

Question 1

where can cell reproduction function

Answer 1

reproduction, growth and development, and repair and renewal

Question 2

what is chromatin

Answer 2

the substance of chromosomes

Question 3

what is combined with proteins to form chromatin

Answer 3

DNA

Question 4

what is the cell cycle

Answer 4

the life of a cell from the time it is formed from a dividing parent cell until its own division into two cells

Question 5

what consists of interphase and mitosis

Answer 5

cell cycle

Question 6

____ replicates before cell division (mitosis), during the S or sythesis phase of interphase

Answer 6

DNA

Question 7

what does a duplicated chromosome consist of

Answer 7

two sister chromatids, joined at the centromere

Question 8

what are the stages of interphase

Answer 8

G1 phase, synthesis, and G2 phase

Question 9

what happens in G1

Answer 9

the cell grows in size and synthesizes

Question 10

what happens in synthesis

Answer 10

DNA in the nucleus is doubled

Question 11

what happens in G2

Answer 11

the cell is preparing to divide

Question 12

what does cell division consist of

Answer 12

mitosis (division of nucleus) and cytokinesis (division of the cytoplasm)

Question 13

what is the function of the spindle

Answer 13

to help separate sister chromatids in mitosis by attaching to the centromere of a duplicated chromosome and pulling sister chromatids to opposite poles of the cell

Question 14

what are the four stages of mitosis

Answer 14

prophase, metaphase, anaphase, and telophase

Question 15

what happens in prophase

Answer 15

the chromatin fibers coil in the nucleus so that the chromosomes become thick enough to be seen individually

Question 16

what happens in metaphase

Answer 16

the centromeres of all the chromosomes line up and the spindle microtubules attach to the sister chromatids

Question 17

what happens in anaphase

Answer 17

the sister chromatids of each chromosome separate and move toward opposite poles of the cell as the spindle microtubules shorten

Question 18

what happens in telophase

Answer 18

begins when two groups of chromosomes have reached opposite ends of the cell and is the reverse of prophase.

Question 19

what is the cell cycle regulated by

Answer 19

a molecular control system that directs the sequential events of the cycle

Question 20

what are the three checkpoints of the cell cycle

Answer 20

G1, G2 and M where the cell stops dividing if there was an error to prevent cancer and abnormal cells

Question 21

what is cancer

Answer 21

an error in the cell cycle which gets past a checkpoint and divides uncontrollably forming a tumor

Question 22

what are gametes

Answer 22

reproductive cells (sperm and egg)

Question 23

what are somatic cells

Answer 23

all cells other than reproductive cells

Question 24

what are homologous chromosomes

Answer 24

two chromosomes composing a pair one from the mother and one from the father - they have the same characteristics

Question 25

what are x and y

Answer 25

the sex chromosomes that determine an individulas sex

Question 26

what are chromosomes other than x and y called

Answer 26

autosomes

Question 27

what are haploid cells

Answer 27

n, one set of 23 chromosomes

Question 28

what are diploid cells

Answer 28

2n, two sets of 23 chromosomes

Question 29

know that

Answer 29

gametes are haploid that are produced during meiosis and they fuse during fertilization producing a diploid zygote

Question 30

what does mitosis and development create

Answer 30

a multicellular diploid adult from this zygote

Question 31

where does meiosis occur in males

Answer 31

the testes as a part of spermatogenesis (sperm production)

Question 32

where does meiosis occur in femails

Answer 32

the ovaries as part of oogenesis (production of eggs)

Question 33

reduces the number of chromosome sets from diploid to haploid by dividing a diploid parent cell into 4 haploid daughter cells in two consecutive divisions

Answer 33

meiosis

Question 34

what are the stages of meiosis I

Answer 34

prophase I, metaphase I, anaphase I, telophase I, and cytokinesis

Question 35

what are the stages of meiosis II

Answer 35

prophase II, metaphase II, anaphase II, telophase II, and cytokinesis

Question 36

what replicated before meiosis I, during the s phase of interphase and doesn't replicate again before meiosis II

Answer 36

DNA

Question 37

what separates homologous chromosomes

Answer 37

meiosis I

Question 38

what separates sister chromatids

Answer 38

meiosis II

Question 39

compare/contrast mitosis and meiosis

Answer 39

MITOSIS Performed by all body cells at some time in their development Produces two daughter cells Includes one nuclear division MEIOSIS Sperm and egg cells Produces four daughter cells four nuclei with half the original number of chromosomes of the parent cell Cells are non-identical Crossingover and pairing happen during meiosis I Resulting cells are identical No pairing of homologous chromosomes, No crossing over

Question 40

what are the three origins of genetic variation among offspring

Answer 40

independent assortment of chromosomes, crossing over, and random fertilization

Question 41

what is an advantage of sexual reproduction

Answer 41

genetic variation