Cell Division Flashcards
1
Q
process by which cells reproduce themselves
A
cell division
2
Q
enables multicellular organism to grow and develop and to replace worn out or damaged tissues
A
cell division
3
Q
cell division consists of two activities:
A
karyokinesis
cytokinesis
4
Q
nuclear division
A
karyokinesis
5
Q
cytoplasmic division
A
cytokinesis
6
Q
two kinds of cell division
A
mitosis
meiosis
7
Q
series of activities through which a cell passes from the time it is formed until it reproduces
A
cell cycle
8
Q
last for about 90% of the cell cycle
A
cell division
9
Q
two major activities of the cell cycle
A
interphase/metabolic phase
cell division
10
Q
referred to as the resting stage of the cell
A
interphase
11
Q
during this stage, the replication of DNA, centrosomes and centrioles occurs and the RNA and protein needed to produce structures required for doubling all cellular components are manufactured
A
interphase
12
Q
three distinct periods of interphase
A
G1
S
G2
13
Q
the G in G1 stands for
A
growth/gap
14
Q
during which cells are engaged in growth, metabolism, and the production of substances required for DNA synthesis and cell division
A
G1 period
15
Q
highly changeable ranging from non-existent in rapidly dividing cells to days, weeks, or years
A
G1 period
16
Q
average time period of G1
A
8-10 hours
17
Q
cells that are intended to never divide again are permanently arrested in this stage
A
G1 phase
18
Q
examples of cells in G1 state after about 6 months of development
A
nerve cells
19
Q
rest in G1 phase becoming permanent cells of the central nervous system
A
nerve cells
20
Q
is the period of interphase during which chromosomes are replicated
A
s period
21
Q
the S in S period stands for
A
synthesis
22
Q
what happens in S period for the DNA
A
double helical structure partially unwinds
strands separate at points where hydrogen bonds join base pairs
23
Q
what happens to the exposed base after the strands separate in s period
A
picks up a complementary pair
24
Q
what will stop the process of exposed base finding their complementary pairs
A
until each of the two original DNA strands is matched and joined with a newly formed DNA strand
25
how long does s phase take place
6-8 hours
26
what happens when a cell goes through S phase
committed to enter cell division
27
the mitochondria divide and the cell continues to grow in preparation for cell division
G2 period
28
since the G-phases are stages when there are no events related to chromosomal replication, they are though of as ___
gaps or interruptions in DNA synthesis
29
karyokinesis
mitosis
30
karyokinesis is divided into what
prophase
metaphase
anaphase
telophase
31
finalizes cell division
cytokinesis
32
time required for mitosis differs with what
kind of cell
location
other factors (temperature)
33
how long does mitosis and cytokinesis happen
1-2 hours
34
somatic "body" cell division
mitosis
35
parent cells divide to produce what
two identical daughter cells
36
the process ensures that each daughter cell has the same number and kind of chromosomes as the original parent cell
mitosis
37
mitosis is the kind of cell division that allows what (3)
growth of multicellular organisms
asexual reproduction
wound healing
38
meaning of pro in prophase
before
39
what happens to the chromatin in prophase
condenses and shortens into chromosomes
40
how many identical double-stranded DNA are there in prophase
a pair
41
pair of double-stranded DNA molecules
chromatids
42
chromatids are held together by a small spherical body called
centromere
43
used for the proper segregation of chromosomes
centromere
44
protein complex that is attached to the outside of each centromere
kinetochore
45
what happens to the nucleoli, nuclear envelope, RNA synthesis in mitosis
nucleoli - disappears
RNA synthesis - stops
nuclear envelope - breaks down and is absorbed in the cytosol
46
what will the centrioles do in prophase
move at the opposite poles of the cells and start to form the mitotic spindle
47
three types of microtubule that form as the mitotic spindle continues to develop
nonkinetochore microtubule
kinetochore microtubule
aster microtubules
48
grow from centrosomes, extend inward, but do not bind to kinetochores
nonkinetochore microtubule
49
grow from centrosomes, extend inward, and attach to kinetochores
kinetochore microtubule
50
grow out of chromosomes, but radiate outward from the mitotic spindle
aster microtubules
51
attachment site for chromosomes and also distributes chromosomes to the opposite poles of the cell
spindle
52
part of prophase that the chromosomes moves toward the equator of the cell
late prophase
53
period when maximum condensation of chromosomes is very evident
metaphase
54
the centromeres of the chromatid pairs line up at the exact center of the mitotic spindle called the
metaphase plate/equatorial plain region
55
characterized by the splitting and separation of centromeres and the movement of two sister chromatids of each pair towards the opposite poles of the cell
anaphase
56
sister chromatids in anaphase are referred to as
daughter chromosomes
57
the movement of chromosomes is due to what in anaphase (kinetochore and nonkinetochure microtubules)
shortening of kinetochore microtubules
elongation of non kinetochore microtubules
58
begins as soon as chromosomal movement stops
telophase
59
opposite of prophase
telophase
60
what happens to the identical set of chromosomes at the opposite poles of the cell in telophase
it uncoils and revert to their threadlike chromatin form
61
what happens to kinetochore/nonkinetochore microtubules in telophase
kinetochore - disappear
nonkinetochore - elongate even more
62
what happens around each chromatin mass in telophase
new nuclear envelope reform around each chromatin mass
63
what happens to the nucleoli and mitotic spindle in telophase
new nucleoli reappear
mitotic spindle breaks up
64
division of parent cell's cytoplasm and organelles
cytokinesis
65
occurs during the telophase stage with formation of the cleavage furrow
cytokinesis
66
slight indentation of the plasma membrane extending around the center of the cell
cleavage furrow
67
what happens when cytokinesis completes
interphase begins
68
result of cytokinesis
two separated daughter cells
69
reproductive "gamete" cell division
meiosis
70
how many haploid nucleis are produced in meiosis
four
71
how many chromosomes produced in mitosis
46
72
how many chromosomes in a daughter cell in meiosis
23
73
can exchange genetic material before being separated (meosis)
homologous chromosomes
74
is the daughter cell different from parents and each other
yes
75
mechanism by which gametes (sex cells) are produced, the basis of sexual reproduction
meiosis
76
what will happen to the number of chromosomes asexually reproducing without meiosis
would be doubled in each generation
77
meiosis is characterized by two successive divisions that result to the formation of haploid gametes
meiosis I and II
78
also called reduction division since the number of chromosomes in a cell is halved (2n -> n)
Meiosis I
79
preceded by interphase apparently identical to that of mitosis, DNA and organelles are duplicated and stored ATP is used
Meiosis I
80
stages of Meiosis I
prophase I
metaphse I
anaphase I
telophase I
81
substages of prophase I
leptonema/leptotene
zygonema/zygotene
pachynema/pachytene
diplonema/diplotene
diakinesis
82
stage of prophase I where there is an initiation of homology search
leptonema/leptotene
83
means "thin threads"
leptonema/leptotene
84
stage of prophase I where chromosomes appear like "beads-on-a-string"
leptonema/leptotene
85
means "yoked threads"
zygonema/zygotene
86
stage of prophase I where condensation continues
zygonema/zygotene
87
stage of prophase I where there is rough pairing
zygonema/zygotene
88
initial alignment of homologous chromosomes
zygonema/zygotene
89
stage of prophase I where bivalents form
zygonema/zygotene
90
what is the number of bivalents
n
91
means thick threads
pachynema/pachytene
92
homologous chromosomes are already distinguished under the microscope
pachynema/pachytene
93
stage of prophase I where there is an intimate pairing of homologous chromosomes
pachynema/pachytene
94
intimate pairing of homologous chromosomes
synapsis
95
the four sister chromatids are evident in pachynema and form a
tetrad
96
suppose that 2n = 6 and n =3 , how many bivalence, tetrads in leptonema
none
97
suppose that 2n = 6 and n =3 , how many bivalence, tetrads in zygonema
bivalence = 3
tetrads = none
98
suppose that 2n = 6 and n =3 , how many bivalence, tetrads in pachynema
bivalence = none
tetrads = 3
99
suppose that 2n = 6 and n =3 , how many bivalence, tetrads in diplonema
bivalence = none
tetrads = 3
100
suppose that 2n = 6 and n =3 , how many bivalence, tetrads in diakinesis
bivalence = none
tetrads =3
101
means "double threads"
diplonema/diplotene
102
one or more areas of the non-sister chromatids remain in contact; sites of crossing over
diplonema/diplotene
103
one or more areas of the non-sister chromatids remain in contact
chiasmata (sing. cihiasma)
104
genetic exchange between maternal and paternal chromosomes
crossing over
105
means "moving apart"
diakinesis
106
chromosome separation proceeds but as this happens, the chiasmata move towards the end of each tetrad
diakinesis
107
the chiasmata moving towards the end of each tetrad
terminalization
108
disintegration of nucleolus and nuclear membrane
diakinesis
109
centromeres of each tetrad attach to the mitotic spindle
diakinesis
110
maximum condensation of chromosomes is attained (meiosis)
metaphase I
111
terminal chiasmata of each tetrad are visible and appear to be the only factor holding the non-sister chromatids together
metaphase I
112
movement of homologous chromosomes to the metaphase plate
metaphase I
113
tetrads separate and dyads move toward opposite poles
anaphase I
114
new nuclear membrane reforms
telophase I
115
nucleus enter into a short interphase
telophase I
116
some cells proceed directly to Meiosis I, skipping this
telophase I
117
also called equatorial division since the haploid cells produced by meiosis I divide producing 4 haploid cells that are genetically different from each other
meiosis II
118
very similar to mitosis in that it results in the separation of sister chromatids
meiosis II
119
stages of meiosis II
prophase II
metaphase II
anaphase II
telophase II
120
each dyad is made up of two sister chromatids joined together by a common centromere
prophase II
121
alignment of centromeres at metaphase plate
metaphase II
122
suppose that 2n = 6 and n =3 , how many bivalence, tetrads, dyads in metaphase I
bivalence = none
tetrads = 3
dyads = none
123
suppose that 2n = 6 and n =3 , how many bivalence, tetrads, dyads in anaphase I
bivalence = none
tetrads = none
dyads = 6
124
suppose that 2n = 6 and n =3 , how many bivalence, tetrads, dyads in telophase I
bivalence = none
tetrads = none
dyads = 6 (in total), 3 (per daughter cell)
125
splitting of centromeres and movement of monads towards the opposite poles of the cell
anaphase II
125
suppose that 2n = 6 and n =3 , how many bivalence, tetrads, dyads in metaphase II
bivalence = none
tetrads = none
dyads = 6 (in total), 3 (per daughter cell)
126
suppose that 2n = 6 and n =3 , how many bivalence, tetrads, dyads in anaphase II
none
127
suppose that 2n = 6 and n =3 , how many monads in anaphase II
in total = 12
per daughter cell = 6
128
monads reach opposite poles
telophase II
129
nucleolus and nuclear membrane reform (meiosis II)
telophase II
130
chromosomes uncoil and become inconspicuous; cytokinesis occurs
telophase II
131
difference between mitosis and meiosis in the kinds of cell they divide
mitosis = somatic
meiosis - gametes
132
suppose that 2n = 6 and n =3 , how many monads in telophase II
total = 12
per DC = 3
133
difference between mitosis and meiosis in the number of divisions per cycl
mitosis = one
meiosis = two
134
difference between mitosis and meiosis in the number of daughter cells formed per cycle
mitosis = two
meiosis = four
135
difference between mitosis and meiosis in the chromosome no. of daughter cells
mitosis = diploid (2n)
meiosis = haploid (n)
136
difference between mitosis and meiosis in progeny/daughter cells
mitosis = genetically identical
meiosis = genetically different
137
difference between mitosis and meiosis in time of cycle
mitosis = throughout life
meiosis = completed after sexual maturity (humans)
138
difference between mitosis and meiosis in uses
mitosis = growth, repair, asexual reproduction
meiosis = sexual reproduction, generating new gene combinations
