Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
38 Cards in this Set
- Front
- Back
|
Cell cycle must coordinate
|
Growth of cell
Duplication of organelles Duplication of DNA Duplication of centrosomes (MTOC) Mitotic spindle apparatus Chromosome condensation/decondensation Chromosome separation Nuclear envelope breakdown/assembly Cytokinesis (cell division) |
|
|
Cytokinesis
|
cell division
|
|
|
In the cell cycle, G1G2 stands for
|
gap or growth
|
|
|
In the cell cycle, S stands for
|
DNA synthesis
|
|
|
In the cell cycle, M stands for
|
mitosis
|
|
|
quiescence
|
G0 phase where the cells are not dividing
|
|
|
G1 + S + G2 =
|
interphase
|
|
|
In the cell cycle, R stands for
|
restriction point
|
|
|
hydrogen-3
|
tritium, a radioactive isotope of hydrogen
|
|
|
In the discovery of _____,
Radioactive tritium, or ³H, was incorporate into ______ |
S phase; thymidine
|
|
|
Grow cells in ³H _____→ If DNA is replicated then ³H-T is incorporated into ____, and therefor the _____ becomes radioactive.
|
thymidine ; DNA; nucleus
|
|
|
Pulse-chase experiment
|
1) Put a mixture of cells in ³H thymidine for 30' (thirty minutes), then wash away the ³H thymidine
2) After 1 hr only a subset of cells had radioactive nuclei. 3) After five hours a few labeled (labeled = tritium incorporated) cells have condensed chromatin (which is a sign of beginning to enter mitosis). 4) After 6 hours labeled cells enter mitosis. |
|
|
Mitosis in a typical human cell takes ____ hours
|
1-2
|
|
|
G1 in a typical human cell takes ___ hours
|
8 hours
|
|
|
S in a typical human cell takes ___hours
|
8 hours
|
|
|
G2 in a typical human cell takes -___hours
|
5 hrs
|
|
|
What are the 6 Stages of mitosis?
|
1) prophase,
2) prometaphase, 3) metaphase, 4) anaphase, 5) telophase, 6)cytokinesis |
|
|
prophase
|
chromosomes condense
Centrosomes migrate and begin to assemble the spindle |
|
|
prometaphase
|
nuclear envelope breaks down
Attach to the spindle |
|
|
metaphase
|
Chromosomes align at the equator
|
|
|
anaphase
|
sister chromoatids simultaneously separate and are puled slowly towards the spindle poles.
|
|
|
telophase
|
chromosomes at the poles begin to decondense
The nuclear envelope begins to reform |
|
|
cytokinesis
|
cells pinch in two by action of microfilaments and their motors
|
|
|
Nuclear lamins
|
found inside nuclear envelope and form meshwork
phosphates added and they fall apart. |
|
|
Chromosome condensation
|
DNA + proteins form chromatin
|
|
|
nucleosome
|
consist of 8 proteins call histones
|
|
|
DNA wraps how many times around nucleosome?
|
Two
|
|
|
How many base pairs from the beginning of one nucleosome to the next.
|
200
|
|
|
Sister chromatids are held together at the _____
|
centromere
|
|
|
______hold chromatids together at the _____
|
cohesins ; centromere
|
|
|
Spindle apparatus
|
microtubules coming out from each side, many of which overlap or come down and grab the end of the cell
|
|
|
kinetochore
|
a protein plaque at the centromere that captures mictrotubules
contains MT motor proteins |
|
|
Astral microtubules
|
grab edge of the cell
stick out towards edge of cell |
|
|
Polar microtubules
|
at middle-cell
come across and connect past the midpoint, overlapping. Often motor proteins that sit in between them that can push them apart. |
|
|
microtubules that attach to kinetochore are called
|
kinetochore microtubules
|
|
|
Minus ends of microtubules are ____
|
buried at the pole
Minus ends of MT in MTOC (microtubules organization center) |
|
|
What's special about Drosophila eggs?
|
12 cycles of nuclear division without cytokinesis
Rapid division of nuclei 20 – 30 minutes No G1 or G2, only M and S |
|
|
What was done in the dropsophila egg experiment?
|
Into the eggs he injected a chemical called DAPI (blue fluorescent that binds DNA)
Also injected tubulin labeled with green fluorescent |
