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Flashcards in Cell Division Deck (56):
1

When a cell is not dividing, each chromosome exists in a single copy called a

chromatid

2

When the cell is preparing to divide, each chromosome must be replicated so that it contains --

2 chromatids (sister chromatids)

3

each chromosome has a compressed region

centromere

4

When the chromosomes replicate the -- stay attached to each other at the centromere

sister chromatids

5

mitosis occurs in most cells except for --, --, --

gametes and mature never and muscle cells in animals

6

during G1, the parent cell is growing larger and is adding -- and replicating --

cytoplasm, organelles

7

first gap phase of the cell cycle

G1 stage

8

phase of DNA synthesis when the chromosomes are all being replicated

S stage

9

Once -- is complete, each chromosome will consist of 2 sister chromatids connected at the centromere

S stage

10

second gap phase

G2

11

During G2 the cell will continue to -- and make final preparations for cell division

grow in size

12

mitosis occurs in this phase

M

13

division of the cytoplasm at the end of the M phase is

cytokinesis

14

interphase = G1, S, G2

preparation for cell division

15

examples of cells that lose the ability to undergo the cell cycle and thus cannot divid

mature human nerve and muscle cells

16

cells without the ability to divide are in the -- phase where division will never resume

G0

17

chromosomes are located in the --

nucleus

18

prior to division, the chromosomes are not condensed and thus are --

not visible

19

leaving the chromosomes in an uncondensed state makes it easier to copy the DNA but makes the chromosomes very --

stringy and fragile

20

once the DNA is replicated, the chromosomes must condense so that they are not -- as they are divided up into the two daughter cells

broken

21

chromosome condensation occurs, making the chromosome visible

prophase

22

During prophase, the -- present in the cello replicate and move to opposite ends of the cell

centrioles

23

When the centrioles reach the poles of the cell, they begin to produce --

spindle apparatus

24

the spindle apparatus consist of spindle fibers that radiate outward forming --

asters

25

spindle fibers are made of -- that will ultimately attach to each chromosome at the kinetochore

microtubules

26

kinetochore (protein structure) appears at the -- of each chromosome

centromere

27

nuclear envelope and lamina is broken down by phosphorylation of the nuclear pore proteins and lamins

prometaphase

28

once the -- breaks down, the spindle microtubules will attach to the chromosomes by binding to the kinetochore

nucleus

29

chromosomes align down the center of the cell

metaphase

30

there is a checkpoint in this phase

metaphase

31

centromere spits, allowing each chromatid to have its own centromere

anaphase

32

during anaphase, the chromatids can be separated and are pulled towards

opposite poles

33

chromatids are moved to opposite poles by -- of the kinetochore microtubules

depolymerization

34

nuclear pore proteins and lamina are dephosphorylated in this phase because the spindle apparatus is no longer needed

telophase

35

during telophase, the -- and -- reform around each set of chromosomes

nuclear envelope and lamina

36

in animal cells, a -- forms that pinches the cells apart from each other

cleavage furrow

37

in plant cells, a -- made of cellulose divides the two daughter cells

cell plate

38

the end result of mitosis, is two daughter cells ready to begin -- of their cell cycle

interphase

39

crossing over occurs in

prophase I

40

crossing over = homologous pairs of chromosomes associate and twist together in --

synapsis

41

the result of crossing over is two replicated chromosomes or a total of four chromatids called a

tetrad

42

T or F: crossing over can occur in more than one location and can unlink genes that were previously linked on the same chromosome

true

43

crossing over is an important source of genetic diversity, creating combinations of -- that were not seen previously

alleles

44

in metaphase of mitosis, chromosomes align -- down the center of the cell

single file

45

in metaphase I of meiosis, the chromosomes align as -- down the center of the cell

pairs

46

law of independent assortment

the alignment of each member of the homologous pair during metaphase I is random giving a unique combination of maternal and paternal alleles

47

during anaphase I, -- will separate from each other and be pulled to the poles of the cells

homologous pairs

48

the separation during anaphase I is referred to as --

disjunction

49

at the end of telophase I, each daughter cell is genetically unique and contains -- number of the chromosomes of the parent cell

half

50

at the end of telophase I, the chromosomes are still in their -- form, consisting of two chromatids

replicated

51

-- split the chromatids present in the daughter cells produced during meiosis I

meiosis II

52

the events in this phase does not occur in all species

prophase II

53

metaphase II

chromosomes align down the center of the cell

54

anaphase II

sister chromatids are separated and move toward the poles of the cell

55

telophase II

nuclear envelopes reform and cytokinesis occurs to produce daughter cells

56

at the end of meiosis II, each daughter cell has a -- copy of each chromosome

single