CELL DIVISION Flashcards
1
Q
Which type of cytoskeleton organizes the chromosomes and splits them in half?
A. Microfilaments
B. Microtubules
C. Intermediate filaments
A
B. Microtubules
2
Q
Which type of cytoskeleton splits the cell in half?
A. Microfilaments
B. Microtubules
C. Intermediate filaments
A
A. Microfilaments
3
Q
What is the Microtubule-organizing center?
- Chromatins
- Centromeres
- Centrosomes
- Kinetochores
- Myofilaments
A
- Centrosomes
4
Q
Microtubule-organizing centers have two
- Centrioles
- Chromatins
- Centromeres
- Kinetochores
A
- Centrioles
5
Q
Which type of cytoskeleton makes up centrioles?
A. Microfilaments
B. Microtubules
C. Intermediate filaments
A
B. Microtubules
6
Q
What is DNA plus the proteins?
- Chromatin
- Centromeres
- Centrosomes
- Kinetochores
- Myofilaments
A
- Chromatin
7
Q
The process of cell division starts with _______-
A
DNA replication
8
Q
During Replication DNA is:
A
Duplicated
9
Q
What happens during mitosis?
A
The two quantities of DNA are moved to opposite sides of the parent cell
10
Q
What happens during cytokinesis:
A
The parent cell splits into two daughter cells
11
Q
Chromosomes are made of ______
A
DNA
12
Q
DNA contains the code that makes ______
A
proteins
13
Q
When does DNA replicate?
A
Just prior to cell division
14
Q
Cells need to divide for :
A
organisms to grow or to replace old cells, or for one celled organisms to reproduce
15
Q
DNA is wound up in coils and folded to form ______
A
chromosomes
16
Q
When the DNA replicates it forms a chromosome in a “______ state”
A
“duplicated state”
17
Q
This “duplicated state” has two strands: each strand is called a ______
A
chromatid – they are “sister chromatids”
18
Q
centromere is where:
A
Where the chromatids are held together
19
Q
After DNA replication each chromosome will be made of ______
A
two sister chromatids
20
Q
These are two chromosomes, each with two _____
A
chromatids
21
Q
What happens in gap one of interphase:
A
cell growth
22
Q
What happens during the S (synthesis) phase of interphase:
A
DNA Replication
23
Q
What happens during gap 2 of interphase:
A
cell growth, preparation for division
24
Q
What happens in the M phase (Mitotic phase) of interphase?
A
Mitosis: division of chromosomes
25
What happens during cytokinesis:
division of cytoplasm
26
Two main phases of cell division:
Interphase and Mitotic phase
27
Interphase prepares for ______
cell division and DNA is replicated
28
Mitotic phase:
Chromosomes separate and cell divides
29
In an average animal cell the cell cycle takes about ____ hours
24
30
Mitosis take only about___ min
30
31
Most of the time of cell division is spent in ___ which is where the cell grows in size – 12 hours
G1
32
Interphase During this phase:
```
The cell grows
Makes new cellular components
DNA is replicated
Check points will stop cell division if
there is a problem
```
33
When the check points in Interphase don’t work properly what happens?
the cell divides when it should not
34
What happens at the end of Interphase:
DNA has replicated
35
Mitosis is divided into four phases:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
36
What happens during Prophase:
1. Chromosomes condense
2. Nuclear membrane breaks down
3. The centrosomes (each centrosome has two centrioles) begin to move to opposite ends of cell
4. Microtubules form
37
During Metaphase Microtubules (mitotic spindles) attach to the
_____
chromosomes
38
During Metaphase: the microtubules line up
| the _____ at the ____
the chromosomes at the center of the cell (the equator)
39
During Prophase _____ begins
Mitosis
40
Metaphase is the stage of _____ and ______
linkage and alignment
41
Anaphase is the stage of ______
Seperation
42
During Anaphase _____ are pulled apart by the _____
Sister chromatids, microtubles
43
During Anaphase Chromatids move toward the ______. Now the chromatids are called ______
poles, chromosomes
44
Telophase and cytokinesis are the ____ stage
exit from mitosis
45
During telophase The chromosomes begin to _____
uncondense
46
During telophase _______ forms
Nuclear membrane
47
During telophase the Cell begins to :
divide in half
48
One cell becomes two at the completion of what stage?
Cytokinesis
49
During cytokinesis Actin microfilaments_____
form pinch the cell in the center
50
During cytokinesis The cell :
divides completely forming two separate cells
51
Where does DNA replication take place?
1. Cytosol
2. Nucleus
2. Nucleus
52
When does DNA replication take place?
1. Metaphase
2. Anaphase
3. Prophase
4. Telophase
5. Interphase
5. Interphase
53
```
During this stage the nuclear membrane
breaks down
1. Metaphase
2. Anaphase
3. Prophase
4. Telophase
```
3. Prophase
54
```
During this stage chromosomes line up at
the equator
1. Metaphase
2. Anaphase
3. Prophase
4. Telophase
```
1. Metaphase
55
During this stage the chromosomes begin to uncondense
1. Metaphase
2. Anaphase
3. Prophase
4. Telophase
4. Telophase
56
```
What happens during anaphase of mitosis?
A. Chromosome pairs separate
B. Sister chromatids separate
C. Chromosomes condense
D. Nuclear envelope reforms
```
B. Sister chromatids separate
57
At the end of Mitosis how many cells are there?
1. One
2. Two
3. Three
4. Four
2. Two
58
At the end of Mitosis, how many chromosomes are there in each cell?
1. 23 chromosomes
2. 46 chromosomes
2. 46 chromosomes
59
At the end of Mitosis, chromosomes are:
1. duplicated
2. unduplicated
2. unduplicated
60
Each daughter new cell has 46 ____ (duplicated/unduplicated) cells
Unduplicated
61
Mitosis occurs in all the body’s cells except the cells that :
are responsible for reproduction
62
Gametes: are the cells that are responsible for _______
reproduction
63
All the rest of the body’s cells are _______
somatic cells
64
gametes undergo _______
meiosis
65
Remember that we have_____- pairs of chromosomes = ____chromosomes
23, 46
66
If gametes (sperm and egg) combined with all these chromosomes then the offspring will have _____ chromosomes
92
67
Before the gametes come together they need to _______
reduce their number of chromosomes in half.
68
So instead of 23 pairs (46 chromosomes) gametes need to have _____ chromosomes total
23
69
The answer to the gametes problem of having too many chromosomes is _____
meiosis –halving their number of chromosomes
70
Meiosis is the process of _____ the chromosomes
halving the chromosomes
71
Do males or females have the XX chromosome?
Females, males have the XY
72
Diploid = cells that have
46 chromosomes or 23 pairs, all somatic cells are diploid (2n)
73
all somatic cells are ______
diploid (2n)
74
Haploid = cells that have
23 chromosomes, gametes are haploid (1n)
75
gametes are _______
haploid (1n)
76
Meiosis is when a :
diploid cell divides to produce haploid reproductive cells
77
In meiosis, first the chromosomes (DNA) are duplicated during _____
Interphase
78
In Meiosis there are _____ cell divisions
two
79
What happens during the 1st cell division of meiosis?
the chromosome pairs separate and the cell divides
80
What happens during the second cell division?
chromatids separate and cell divide
81
How many haploid cells come out of the 1st meiosis division?
2
82
How many haploid cells come out of the 2nd meiosis division?
4
83
Remember Meiosis happens to form _______
gametes
84
The cells that produce the gametes start out ____ before meiosis, and will end up _____
diploid, haploid
85
There are _____ stages of Meiosis
two
86
Each Stage of Meiosis has _____, _______, _______, ________
Prophase, Metaphase, Anaphase, and Telophase
87
crossing over definition:
genetic material is exchanged between the homologous chromosomes
88
Prophase I: Duplicated chromosomes condense and intertwine – this produces _______
genetic variation
89
During prophase I __________ begins to break down
Nuclear membrane begins to break down
90
Microtubules form during :
Prophase I
91
Crossover occurs during :
Prophase I
92
During ________: The microtubles line up the chromosomes at the center of the cell (the equator)
metaphase I
93
independent assortment=
The chromosomes arrange themselves randomly – this also gives genetic variation
94
During Anaphase I:
chromosomes in the pairs are separated
95
During Telophase I:
1. Nuclear membrane forms
| 2. Cell divides in half
96
During telophase I, The chromosomes are in the ________ (duplicated/unduplicated) form
duplicated
97
Prophase II: The 23 chromosomes are already condensed. The _________ dissolves.
Nuclear membrane
98
Metaphase II: Chromosomes line up at the _______
equator
99
During Anaphase II:
Chromatids separate
100
During Telophase II:
Cells separate
101
At the end of Meiosis II, there are _____ haploid cells: each has _____
chromosomes, not in the ______ (duplicated/unduplicated) state
four, 23, duplicated
102
```
At the end of Meiosis I how many cells are
there?
1. One
2. Two
3. Three
4. Four
```
2. Two
103
At the end of Meiosis I are these cells haploid or diploid?
1. Haploid
2. Diploid
1. Haploid
104
At the start of Meiosis I, how many
chromosomes are there in each cell?
1. 23
2. 46
2. 46
105
At the start of Meiosis I, are the chromosomes in the duplicated state?
1. Yes
2. No
1. Yes
106
At the end of Meiosis I are these cells haploid or diploid?
1. Haploid
2. Diploid
1. Haploid
107
At the end of Meiosis I, how many
chromosomes are there in each cell?
1. 23
2. 46
1. 23
108
At the end of Meiosis I, are the chromosomes in the duplicated state?
1. Yes
2. No
1. Yes
109
```
At the end of Meiosis II how many cells are
there?
1. One
2. Two
3. Three
4. Four
```
4. Four
110
At the end of Meiosis II are these cells haploid or diploid?
1. Haploid
2. Diploid
1. Haploid
111
At the end of Meiosis II, how many chromosomes are there in each cell?
1. 23 chromosomes
2. 46 chromosomes
1. 23 chromosomes
112
At the end of Meiosis II, are the
chromosomes in the duplicated state?
1. Yes
2. No
2. No
113
```
What happens during anaphase of meiosis I?
A. Chromosome pairs separate
B. Sister chromatids separate
C. Chromosomes condense
D. Nuclear envelope reforms
```
A. Chromosome pairs separate
114
```
What happens during anaphase of meiosis II?
A. Chromosome pairs separate
B. Sister chromatids separate
C. Chromosomes condense
D. Nuclear envelope reforms
```
B. Sister chromatids separate
115
What are the two places in meiosis that contribute to the genetic diversity of an offspring?
Prophase I: The pairs of chromosomes crossing over.
| Metaphase I: The way the chromosomes line up on the equator is random = independent assortment
116
Eggs will contain a _____ chromosome
X chromosome
117
Sperms will contain _______ chromosome
either a X or a Y
118
In the male testes sperm are produced. One cell produces ___ sperm.
4 sperm
119
Each sperm has ___ chromosomes, they are not in the ______ form
23, duplicated
120
The heads of the sperm contain the _____ and ______ to power the flagella
chromosomes and lots of mitochondria
121
About ______ million sperm are produced each day
400 million
122
One cell will produce one egg and three non-
| functioning “______"
"polar bodies”
123
All of the cells that produce the eggs are made :
before the female mother is even born.
124
Each month one of these cells will leave the ovary and go on to mature – and produce the ______ and _______
egg and polar bodies
125
Mitosis and Meiosis both start with a _______ cell
diploid
126
Before both Mitosis and Meiosis the DNA replicates, forming ________
duplicated chromosomes, each containing two chromatids
127
During Mitosis The chromatids are separated to produce two cells, each with 46 chromosomes, 23 pairs of ______ (non duplicated/duplicated) chromosomes
non duplicated
128
Meiosis I: the pairs of ______- line up and the ______ are separated, resulting in 2 cells, each with 23 chromosomes, in the duplicated state
chromosomes, chromosomes
129
Meiosis II: The ______ are separated producing two haploid cells that contain 23 non duplicated chromosomes
chromatids
130
One original cell produces ______ haploid cells
four
