2: Chromosomes & Cellular Reproduction

Question 1

two chromosomes that are usually alike in structure and size, and each carries genetic information for the same set of hereditary characteristics

Answer 1

homologous pair

Question 2

cells that carry two sets of genetic information (2 sets of chromosomes, 1 homologous pair) 2n

Answer 2

diploid

Question 3

cells that carry one set of genetic information (reproductive cells) n

Answer 3

haploid

Question 4

cells that carry more than two sets of genetic information

Answer 4

polyploid

Question 5

attachment point for spindle microtubules on chromosome

Answer 5

centromere

Question 6

multiprotein complex that assembles on the centromere and serves as an attachment point for spindle microtubules later on

Answer 6

kinetochore

Question 7

the natural ends, or tips, of a whole linear chromosome. function to protect and stabilize the chromosome ends

Answer 7

telomeres

Question 8

two initially identical copies of a chromosome held together at the centromere. consists of a single molecule of DNA

Answer 8

sister chromatids

Question 9

when the number of chromosomes increases (mitosis)

Answer 9

only in anaphase (two chromatids separate and become distinct chromosomes)

Question 10

when number of chromosomes decreases (mitosis)

Answer 10

only through cytokinesis

Question 11

when number of DNA molecules increases and decreases (mitosis)

Answer 11

increases only in S phase and decreases only through cytokinesis

Question 12

first division of meiosis

Answer 12

reduction division (chromosomes/cell reduced by half)

Question 13

second division of meiosis

Answer 13

equational division

Question 14

a very close pairing association between homologous chromosomes

Answer 14

synapsis

Question 15

each homologous pair of synapsed chromosomes consists of four chromatids

Answer 15

tetrad or bivalent

Question 16

when does crossing over take place?

Answer 16

prophase I of meiosis

Question 17

when do homologous chromosome pairs separate (meiosis)

Answer 17

anaphase I

Question 18

when do sister chromosomes separate (meiosis)

Answer 18

anaphase II

Question 19

number of possible combinations of chromosomes in gametes

Answer 19

2^n, n=number of homologous pairs

Question 20

protein that holds chromatids together

Answer 20

cohesin

Question 21

enzyme that breaks down cohesin along length of sister chromatids and allows them to separate

Answer 21

separase

Question 22

phase of cell growth, chromosomes are unduplicated

Answer 22

G1

Question 23

non-dividing phase, where most cells reside

Answer 23

G0

Question 24

DNA duplicates in this phase

Answer 24

S

Question 25

duplicated chromosomes prepare for mitosis

Answer 25

G2

Question 26

Mitotic Division (conservative vs. nonconservative)

Answer 26

conservative for chromosome number, nonconservative for DNA molecule number

Question 27

independent alignment of maternal and paternal copies of different homologous chromosomes

Answer 27

independent assortment