quiz #4

Question 1

G1 phase

Answer 1

initial growth phase, cell accumulates materials for DNA replication

Question 2

S phase

Answer 2

DNA replication occurs (synthesis phase)

Question 3

G2 phase

Answer 3

cell continues to grow and prepares for mitosis

Question 4

mitotic phase (IMPAT)

Answer 4

cell divides, mitosis produces two identical cells

Question 5

prophase

Answer 5

nuclear envelope breaks down to access chromosomes

Question 6

metaphase

Answer 6

chromosomes align at the metaphase plate

Question 7

anaphase

Answer 7

sister chromatids separate

Question 8

telophase

Answer 8

nuclear envelope rebuilds around sister chromatids

Question 9

cytokinesis

Answer 9

division of the cytoplasm following mitosis or meiosis

Question 10

prokaryotic genome

Answer 10

know the structure of prokaryotic genomes
- usually a single, circular DNA molecule (in contrast with eukaryotic linear chromosomes)

Question 11

genome

Answer 11

complete set of DNA within the nucleus (eukaryotes) or single molecule (prokaryotes)

Question 12

centrosome

Answer 12

organizes mitotic spindle for cell division

Question 13

purpose of meiosis

Answer 13

creates genetic variation and reduces chromosome number by half in gametes, preparing for fertilization. meiosis results in four genetically diverse cells

Question 14

gametes

Answer 14

reproductive cells, like sperm and egg
human diploid cells contain 46 chromosomes, haploid gametes contain 23

Question 15

crossing over

Answer 15

exchange of genetic material in prophase 1. Genetic material exchange, creating recombinants

Question 16

homologous chromosomes

Answer 16

chromosomes with the same length and gene types

Question 17

fertilization

Answer 17

fusion of haploid gametes to form a diploid zygote

Question 18

genetic variation

Answer 18

due to meiosis and fertilization

Question 19

G2 checkpoint

Answer 19

checks for complete, undamaged DNA before mitosis

Question 20

proto-oncogenes

Answer 20

regulate cell growth, mutations can lead to uncontrolled cell division (cancer)

Question 21

p53

Answer 21

tumor suppressor that halts the cell cycle for DNA repair or induces apoptosis in damaged cells, helping prevent cancer
- mutations in genes like p53 and RB1 prevent the cell from stopping division despite damage, often seen in cancer cells