Chapter 12: Flashcards
(132 cards)
1
Q
What are nonproductive cells called?
A
somatic
2
Q
What are reproductive cells called?
A
gamatic cells
3
Q
How many cells are produced in somatic cell division?
A
2 identical
4
Q
How many chromosomes are in somatic cells?
A
46
5
Q
How many cells are in gametes?
A
23
6
Q
What does DNA contain?
A
chromosome
7
Q
Each gene is for one __________
A
characteristic
8
Q
What does chromatin contain?
A
DNA and protein
9
Q
What is asexual reproduction?
A
a single individual passes all of its genes to its offspring without the fusion of gametes
10
Q
What is a clone?
A
a group of genetically identical individuals from the same parent
11
Q
What is sexual reproduction?
A
two parents give rise to offspring that have unique combinations of genes inherited from the two parents
12
Q
What method do hydra cells use to reproduce?
A
The budding method
13
Q
What is a karyotype?
A
is an ordered display of the pairs of chromosomes from a cell
14
Q
What is the 22 chromosome?
A
Autosome
15
Q
xx =
A
female
16
Q
xy =
A
male
17
Q
What is a diploid cell?
A
(n + n) has two sets of chromosomes
18
Q
What is a haploid cell?
A
(n) has one set of chromosomes
19
Q
For humans what is the haploid #?
A
23
20
Q
What is the chromosome of an unfertilized egg?
A
x
21
Q
What is a zygote?
A
A fertilized egg that has one set of chromosomes from each parent
22
Q
What is the division of somatic cells called?
A
mitosis
23
Q
What is the division of gamete cells called?
A
meiosis
24
Q
Is a zygote a haploid or diploid?
A
diploid
25
How many stages are there in meiosis?
2
26
What is the stage before meiosis?
interphase
27
What enters meiosis I?
A pair of homologous chromosomes in one cell
28
What happens in meiosis I?
homologous chromosomes separate into haploid cells with duplicated chromosomes
29
What happens in meiosis II?
sister chromatids separate
30
What are the 4 parts of meiosis I?
prophase I
metaphase I
anaphase I
telophase I and cytokinesis
31
What is metaphase I?
All chromosome pairs are aligned int he center of the cells
32
In metaphase I, microtubules are attached to what?
kinetochore
33
What is the end product of meiosis I?
2 cells containing half of the DNA that the original cell started with
34
Where is the chiasmata?
prophase I
35
What is a chiasmata?
the cross over point os sister chromosomes from mom and dad
36
What is a synaptonemal complex?
The zipper like structure that holds two parent chromosomes together
37
Is there chiasmata in mitosis?
no
38
Mitosis takes 2n and creates ________
2 more cells of 2n
39
Meiosis takes 2n and creates ________
4 n cells
40
What is the narrow part of a chromosomes called?
centromere
41
CHECK
| After duplication in interphase what are chromosomes referred as?
sister chromatid
42
What is cell cycle?
Life from being a parent cell to two daughter cells
43
What are the three major steps in mitosis?
1. replicates its DNA
2. splits two copies to either side of the cell
3. entire cells splits in half into two daughter cells
44
What is a cells genetic information called?
genome
45
What is the difference between a eukaryotic and prokaryotic genome?
A prokaryotic cell has a genome of one single stand of DNA while a eukaryotic has multiple
46
What is a chromosome?
tightly packed DNA molecule
47
What is chromatin?
DNA molecule + associated proteins
48
When condensed what does chromatin make up?
chromosomes
49
What is a chromosome called after being duplicated?
Sister chromatid
50
What connects sister chromatids?
cohesions
51
What is a centromere?
A region made up of repetitive sequences of DNA where the two sister chromatids are most connected
52
What causes a duplicated chromosome to have a "narrow waist"?
condensed DNA caused by bound proteins
53
What is the portion of the chromatid on either side of the centromere referred to as?
the arm of the chromatid
54
Which process of cell division is used to replace damaged cells?
mitosis
55
which process of cell division is used to produce gametes?
meiosis
56
What is typically the shortest part of the cell cycle?
mitotic phase
57
What accounts for 90% of the cell cycle?
interphase
58
What are the 3 smaller steps of interphase?
G1, S, and G2
59
Where does duplication of the chromosomes occur?
S phase
60
What are the main purposes of the G1 and G2 phase?
to grow the cell
61
Where does the division of the cell actually happen in somatic cells?
Mitotic Phase
62
What are the 5 stages of Mitosis?
1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase/Cytokinesis
63
What stage do mitotic spindles develop?
Prophase
64
What are mitotic spindles made of?
microtubules
65
What are centrosomes?
Regions in animal cells that organize the microtubules of the mitotic spindles?
66
How many centrosomes are there in G2 of Interphase?
2
67
Are the chromosomes leaving G2 phase condensed or uncondensed?
uncondensed
68
In what stage of mitosis does the mitotic spindle form?
Prophase
69
In what stage of mitosis do the sister chromatids condense and match up via cohesions?
Prophase
70
What is an Aster?
The radial arrays of shorter microtubules that extend from the centrosome
71
What happens to the nucleoli in prophase of mitosis?
it disappears
72
What happens to the centromeres in Prophase of mitosis?
they move away from each other due to microtubules
73
In what stage of mitosis does the nuclear envelope fragment?
Prometaphase
74
what does nuclear envelope fragmentation allow in prometaphase?
Allows for microtubules extending from the centrosome to invade the nuclear area
75
What is a kinetochore?
A specialized protein lovcated on the centromere
76
What happens when a microtubules attached to a kinetochore?
they are pulled toward the pole that the microtubules extend from
77
What stops the movement of chromosome towards the pole of the microtubules during prometaphase?
When another microtubule attaches to the other kinetochore of the sister chromatid
78
What do microtubules do that do not connect to kinetochore?
They connect to opposite microtubules, expanding the cell
79
In what stage of mitosis are centrosomes on the opposite side of the cells?
Metaphase
80
What is the main event of metaphase?
Chromosomes line up on metaphase plate
81
What is metaphase plate/
the equator of the cell
82
Where do the chromosomes centromeres lie in metaphase of mitosis?
on the metaphase plate
83
What is the shortest stage of mitosis?
Anaphase
84
What is the first step of Anaphase in mitosis?
cohesion proteins of sister chromatids are cleaved
85
What is the main event of Anaphase?
Two sister chromatids are separated into chromosomes and pulled to opposite poles
86
Elongation during anaphase of mitosis is due to what?
nonkineuechore microtubules lengthening
87
Why do daughter chromosomes in Anaphase move towards opposite poles?
Their kinetochore microtubles shorten
88
If one where to start off with 10 chromosomes, how many would be on EACH pole in Anaphase and how many would there be in total?
20 in total
| 10 on each pole
89
What is the main event of telophase in mitosis?
Two separate nucleus are formed.
90
What is the main event of cytokinesis in mitosis?
The cell divides into two cells
91
What is a cleavage furrow?
In cytokinesis the point at which the cell is pinching in
92
Regarding the cleavage furrow, what is on the cytoplasmic side?
actin microfilaments
93
What do actin microfilaments react with that cause the ring to contract?
myosin
94
Cleavage furrow is to animals cells as _________ is to plant cells?
Cell Plate
95
What is the cell plate made of?
vesicles
96
What is binary fission?
When a cell grows twice its size and then divides in half
97
What type of reproduction is binary fission?
asexual
98
In bacteria, how is DNA carried
in a circular DNA molecules and associated proteins
99
What is the origin of replication?
specific place on a bacterial chromosome that begins to replicate
100
What are the steps of binary fission?
1. origin replicates
2. origin moves to opposing sides of the cell
3. chromosome continues to replicate and cell elongates
4. proteins cause plasma membrane to pinch in
5. Cell completely divides
101
What are the sequential events of the cell cycle directed by?
Cell cycle control system
102
What is a cell checkpoint?
A point of the cell cycle control system that has stop/go signals
103
Where are the 3 important checkpoints of mitosis founds?
G1, G2, and M phase
104
What are the two main regulatory proteins of the cell cycle control system?
Cdks and cyclins
105
What are protein kinases?
Enzymes that activate other proteins via phosphorylation
106
T or F? most protein kinases are in an inactive form?
T
107
What must a Cdk attach to activate?
cyclin
108
Of the proteins involved in the cell cycle control system, which is held at concentration throughout the growth of the cell?
cdk
109
A cyclin + CDK = ?
MPF
110
What does MPF stand for?
M-Phase Promoting Factor
111
Peaks of MPF correspond to peaks in what?
cyclin concentration
112
When are MPF concentrations at their highest in regard to the different stages of mitosis?
metaphase
113
What causes MPF to switch off?
cyclin is destroyed
114
What is arguable the most important checkpoint in mitosis?
The G1 checkpoint
115
What is the non dividing state of a cell called?
G0 phase
116
What phase are most cells in our body kept at?
G0 phase
117
Anaphase not continuing without ALL kinetochore molecules being connected to microtubules is an example of what kind of signal/
internal
118
What is a growth factor?
A protein released by certain cells that stimulates other cells to divide
119
During injury PDGF molecules are released by platelets, detected by receptors on the outside of the plasma membrane, and thus trigger cells to divide. PDGF in this case is an example of what?
A growth factor
120
Growth factors are examples of what kind of signal?
external
121
What is density-dependent inhibition?
The phenomenon in which crowded cells stop dividing?
122
Why do cells stop dividing when they are touching?
Both have receptor for a surface cell protein on other cells
123
What is anchorage dependence?
To divide, cells must be attached to a substratum
124
What is the overarching difference between cancer calls and regular cells?
Cancer cells have deranged cell cycles
125
What is the term for when a normal cell begins to behave like a cancer cell?
transformation
126
Normally, how many times will a cell divide?
20-50
127
What is a benign tumor?
A stagnant tumor
128
What is a malignant tumor?
A tumor that is able to spread to other tissue
129
What is metastasis?
The movement of cancerous cells
130
How is a localized tumor treated?
High energy radiation
131
How is cancer treated when it has spread?
chemotherapy
132
What doe chemotherapy do on a cellular level?
Causes cells to stop dividing because block the creation of mitotic spindle
