Chapter 12: Mitosis Flashcards
(75 cards)
1
Q
Cells make copies of themselves via what processes
A
Mitosis and Cytokinesis
2
Q
what the cell copies are called
A
daughter cells
3
Q
cell divison functions
A
reproduction
growth and development
tissue renewal
4
Q
How long can a red blood cell live before it is replaced
A
4 months
5
Q
How long can a white blood cell live before it is replaced
A
1 year
6
Q
How long can a skin cell live before it is replaced
A
2-3 weeks
7
Q
How long can a colon cell live before it is replaced
A
4 days
8
Q
How long can a nerve cell in the brain live before it is replaced
A
our entire life and even longer
9
Q
“body cells”
A
somatic
10
Q
have the total
number of chromosomes of the adult
organism
A
somatic
11
Q
“Sex cells”
A
germ
12
Q
reproductive cells, have
half the total number of chromosomes of the
adult organism.
A
germ
13
Q
long, thin DNA fiber and proteins (only found when cell is not replicating DNA
A
chromatin
14
Q
condensed form of a DNA molecule with its attached proteins (observed under microscope during replication)
A
chromosome
15
Q
Place where chromatids attach
A
centromere
16
Q
how many chromosomes do humans have?
A
46
17
Q
how many chromosomes do fruit flies have?
A
8
18
Q
how do eukaryotic cells reproduce or copy?
A
mitosis
19
Q
how do prokaryotic cells reproduce or copy?
A
binary fission
20
Q
steps of binary fission
A
on notes
21
Q
Longest part of the cycle; cell
increases mass, duplicates DNA. The cell can
stop in interphase if environmental conditions
deteriorate.
A
Interphase
22
Q
what happens during interphase?
A
cell increases in mass
duplicates DNA
23
Q
parts of Interphase
A
Gap 1 (G1)
DNA Synthesis (S)
Gap 2 (G2)
24
Q
what does Gap 1 (G1) do
A
cell growth before DNA replication
25
what does Synthesis (S) do
DNA replication
26
what does Gap 2 (G2) do?
cell prepares for division
27
five parts of mitosis
1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase
28
what happens in prophase?
- Chromosomes begin condensing and become
visible
- The nucleoli disappear
- microtubules begin to form and become visible
and Extend from each replicated centrosome
29
what happens in prometaphase?
* The nuclear envelope begins to break down
* Some microtubules attach to the kinetochore
* Some microtubules attach to each other from
opposite poles within the cell and extend and force the cell to enlarge
30
A 3-layer protein structure (disk) that is located at
or near the centromere of each chromosome
kinetochore
31
The area where microtubules (kinetochore fibers)
attach to the chromosome
kinetochore
32
Region of the chromosome where sister chromatids are attached in the condensed chromosome
Centromere
33
A microtubule organizing and production center
centrosome
34
9 pairs of triplet microtubules found within the centrosome of animal cells
centriole
35
what happens at metaphase?
* Centrosomes at opposite poles (ends) of cell
* Chromosomes are moved to the center of
the cell by microtubules and are line up
along the metaphase plate
36
what is the cell's equator called?
metaphase plate
37
what happens in anaphase
* The 2 chromatids physically separate when the
centromere divides.
* Each daughter chromosome is hen “pulled” to
opposite ends of the cell by a shortening of the
microtubules attached to chromatids
* Other microtubules (attached to each other from o
opposite poles) increase in length which increases
the cell size
38
what mechanism is used by the Motor proteins that “walk” the chromosomes along the kinetochore fibers to opposite poles as these fibers shorten from the
kinetochore end
“Pac-man” mechanism
39
division of one nucleus into 2 genetically identical nuclei)
mitosis
40
what happens in telophase?
*The chromosomes at the opposite ends uncoil
* A new nuclear envelope forms
* The spindle fibers break down and disappear.
* Mitosis is complete.
41
brief synopsis of cytokinesis
The cytoplasm is cleaved in half and the
new cell membrane grows to enclose both
cells (the original cell and the daughter cell).
[different in plant and animal cells]
42
how does cytokinesis happen in plant cells?
A double membrane cell plate formed by vessicles
(produced by Golgi Apparatus)
--> Between the membrane, the cell wall will form
43
how does cytokinesis happen in animal cells?
Process known as cleavage
– A cleavage furrow is formed
* Furrow deepens until
cell is pinched in two
44
Made of a contractile ring of actin and myosin
proteins
cleavage furrow
45
The frequency of cell division varies with
the type of cells
46
what cells in a mature human do not divide at all?
nerve and muscle cells
47
3 main checkpoints of the Cell-Cycle Control System
G1(both during interphase)
G2
M Phase (during Mitosis)
48
what regulates the cycle
Rhythmic fluctuations in the concentration of
particular molecules
49
Some of these regulatory molecules are what
protein kinases
50
enzymes which activate proteins by phosphorylating them
Protein kinases
51
The activity of some kinases are dependent on
regulatory proteins (cyclins) which attach to the
kinases and activate them making them what
cyclin-dependent kinases (Cdks)
52
Mitosis promoting factor triggers the cell’s passage
through the G2 checkpoint into the Mitosis Phase
MPF
53
also destroys its own cyclin which deactivates
itself
MPF
54
remains intact to then interact with
new cyclin if available
CDK portion
55
A signal that delays anaphase originates at the what
kinetochores that aren't yet attached to microtubules
56
how does the anaphase Promoting Complex (APC) become active?
when all of the kinetochores have attached to the microtubules
57
is a protein released by certain body cells that stimulates other cells to divide
a growth factor
58
is made by platelet blood cells (important in wound healing) is required for division of fibroblasts (cells that secrete fibers in connective tissue)
platelet-derived growth factor
(PDGF)
59
what does the Binding of PDGF to its specific receptors (T-K receptors) do?
triggers a signal transduction pathway
that ends in cell division
60
When the cell population reaches a certain
density, the amount of required growth factors
and nutrients available to each cell becomes
insufficient to allow continued cell growth
Density-Dependent Inhibition of Cell Division
61
what happens bc of Density-Dependent Inhibition of Cell Division
crowed cells stop dividing
62
(extracellular matrix of a tissue)
substratum
63
In order to divide the cells must be attached to what?
substratum
64
When abnormal cells are not destroyed, they may
proliferate to form a what?
tumor
65
an unregulated growing mass of cells within otherwise normal tissue
tumor
66
If the cells remain at this original site, the mass is
called a
benign tumor
67
is invasive enough to impair normal function of 1 or more organs of the body.
malignant tumor
68
Only an individual with a what is said
to have cancer
malignant tumor
69
properties of a malignant tumor
* Abnormal cell cycle; excessive proliferation
* May have unusual number of chromosomes
* Lost attachments to neighboring cells and
extracellular matrix
* Angiogenesis
70
stimulation of new blood vessels
angiogenesis
71
This spread of cancer beyond their original sites is
called
metastasis
72
If a tumor metastasizes it is usually treated with what?
radiation and chemotherapy
73
cell suicide controlled by the p53
gene. This is done after the cell has performed
its function or if the cell becomes altered in
ways such as infection or cancerous
transformation that might pose a threat to the
whole body.
apoptosis
74
In cancer cells the what has been tampered with
or shut down.
p53
75
normally induces apoptosis if a cell’s DNA gets damaged.
p53
