Chromosomes & The Cell Cycle

Question 0

Prokaryote vs. eukaryote chromosomes

Answer 0

Prokaryote: short and circular

Eukaryote: long and linear

Question 1

What is a chromosome?

Answer 1

A strand of DNA that carries genetic info in a cell

Question 2

Prokaryote basics

Answer 2

no nucleus

Single celled

Always haploid

Question 3

Eukaryote basics

Answer 3

Have a nucleus

Some single celled, some multicellular

Both haploid and diploid

Question 4

Every cell has it’s own ____ and can be ___ or ___

Answer 4

Genes, haploid, diploid

Question 5

Haploid definition

Answer 5

1 copy of every gene

Question 6

Diploid

Answer 6

2 copies of every gene

1 from mom and 1 from dad

Question 7

Mitosis definition

Answer 7

Cell division that makes 2 daughter cells identical to the mother cell–whether haploid or diploid

Question 8

Meiosis definition

Answer 8

Cell division that splits diploid cells into haploid cells

Question 9

Cell division in prokaryotes

Answer 9

Very simple–circular haploid chromosome of DNA duplicates, then cell splits in two

Result: 2 identical haploid daughter cells

Question 10

Human diploid cell chromosome #

Answer 10

23 pairs, or 46 chromosomes

Question 11

After DNA duplication, Human diploid cell chromosome #

Answer 11

23 pairs, or 46 chromosomes

BUT each chromosome has a sister chromatid = 92 chromatids in the cell

Question 12

When the cell is about to divide it first…

Answer 12

Duplicates chromosomes

Question 13

After duplication of chromosomes…

Answer 13

Each chromosome consists of 2 sister chromatids

Question 15

Human haploid and diploid #s

Answer 15

Haploid (N) = 23

Diploid (2N) = 46

Question 16

spindle fiber

Answer 16

long protein molecule (microtubule) that tows chromosomes during division

Question 17

centromere

Answer 17

area of a chromosome where spindle fibers attach during division

Question 18

kinetochore

Answer 18

protein structure on a centromere where spindle fibers attach

Question 19

centrosome

Answer 19

the structure (centriole + aster) where microtubules pull the chromosomes

aka. microtubule organizing center (MTOC)

Question 20

centriole

Answer 20

strange little cylinder made of short microtubules

located at the center of a centrosome

Question 21

aster

Answer 21

cluster of spindle fiber

converge at centrosome

Question 22

bands on chromosomes

Answer 22

numbered in both directions starting at centromere

only visible when chromosomes are stained with a special technique

Question 23

the earlier in ___ the longer the chromosomes are, and more bands are ____

Answer 23

prophase, visible

Question 24

karyotype

Answer 24

visual of a person’s 23 chromosome pairs

Question 25

during the mitotic cell cycle a human cell has how many chromosomes?

Answer 25

46 (23 pairs)

Question 26

during the mitotic cell cycle is a human cell always diploid?

Answer 26

yes

Question 27

interphase

Answer 27

happens between cell divisions chromosomes are decondensed and invisible 3 stages (G1, S, G2)

Question 28

G1

Answer 28

each chromosome consists of 1 chromatid

Question 29

S

Answer 29

DNA is duplicated

Question 30

G2

Answer 30

each chromosome consists of 2 chromatids

Question 31

G0

Answer 31

some cells exist in this state of non-division may be permanent (nervous cells) or reversible (immune cells)

Question 32

at what stage can you see a karyotype?

Answer 32

at the end of G2 in interphase

Question 33

cytokinesis

Answer 33

dividing the cytoplasm and membrane

Question 34

at mitosis the cell splits each _____ into _____

Answer 34

2-chromatid chromosome, single-chromatid chromosomes

Question 35

higher plants don't have...

Answer 35

centrioles

Question 36

the haploid number of chromosomes is called __ and the diploid number is called ___

Answer 36

N, 2N

Question 37

in simple eukaryotes the ___ stage of life is dominant

Answer 37

haploid

Question 38

fungi spend most of their lives as ____

Answer 38

haploids, growing as little invisible threads called mycelia

Question 39

more complex plants spend most of their lives as ___

Answer 39

diploids

Question 40

animals spend their whole lives as ____ except for the _____ stage

Answer 40

diploids, gamete

Question 41

the diploid stage of any eukaryote begins with ____

Answer 41

syngamy: when two haploid gametes combine to form a diploid cell

Question 42

meiosis can only occur in the ___ stage because...

Answer 42

diploid it requires a cell with pairs of homologs

Question 43

what are the two types of cells in animals in the diploid stage?

Answer 43

somatic and germline

Question 44

somatic cells

Answer 44

everything other than germline only go through mitosis

Question 45

germline cells

Answer 45

exist only in the gonads (testes & ovaries) go through either mitosis OR meiosis

Question 46

what is the important function of meiotic recombination?

Answer 46

to shuffle the genes, making new chromosomes with new combinations of parental alleles