BIO 202 Unit 3 terms

Question 1

G1 phase

Answer 1

longest phase; when the cell is growing and metabolically active

Question 2

S phase

Answer 2

when DNA synthesis (replication) takes place

Question 3

G2 phase

Answer 3

cells prepare for cell division

Question 4

M phase

Answer 4

cell division (mitosis or meiosis) occurs as well as cytokinesis

Question 5

helicase

Answer 5

separates the two parental strands

Question 6

single-strand binding proteins (SSBPs)

Answer 6

keep the separated parental strands from rejoining

Question 7

topoisomerase

Answer 7

keeps the DNA strand that is not yet separated from coiling up

Question 8

primase

Answer 8

RNA polymerase that creates RNA primer on the lagging strand

Question 9

DNA pol III

Answer 9

synthesizes the leading strand; replaces RNA primer with DNA on the lagging strand

Question 10

DNA pol I

Answer 10

extends the Okazaki fragment on the lagging strand

Question 11

DNA ligase

Answer 11

zips the DNA back up

Question 12

in which direction is DNA synthesized?

Answer 12

5’-3’ where new pieces are added onto the 3’ end

Question 13

chromosome

Answer 13

a piece of a genome

Question 14

gene

Answer 14

a specific region of a chromosome where the sequences of bases in that region contain the information to make a unique RNA

Question 15

genome

Answer 15

the entire genetic information of a cell in the sequences of bases in DNA

Question 16

homolog/homologous chromosomes

Answer 16

same in shape or size, but have slightly different alleles

Question 17

alleles

Answer 17

alternate versions of a gene

Question 18

karyotype

Answer 18

number and types of chromosomes in a cell

Question 19

chromatid

Answer 19

a double-stranded DNA copy of a replicated chromosome

Question 20

sister chromatids

Answer 20

identical pieces of a replicated chromosome that are attached to each other; when separated they become individual chromosomes

Question 21

diploid cells

Answer 21

2n; have two of each chromosome type

Question 22

haploid cells

Answer 22

n; have one of each chromosome type

Question 23

what is the difference between homologous chromosomes/pairs and sister chromatids?

Answer 23

homologous pairs are not identical; sister chromatids are identical

Question 24

independent assortment

Answer 24

alleles of different genes don’t stay together when gametes form