Transcript Mitosis Study Cards

Mitosis Flash Cards
Ch 4
Why do cells divide
rather than continuing
to grow indefinitely?
-The larger the cell becomes, the
more demands it places on the
DNA
-The cell has trouble moving
enough nutrients and wastes
across the cell membrane
Surface area to volume
What limits the
ratio
maximum size a cell
can get?
What is cell division? The process by which 2
new cells are produced
from one cell.
What are the 4
phases of the cell
cycle?
1. G1 Phase
2. S Phase
3. G2 Phase
4. M Phase
1. Cell Growth – the cell increases
in size
What happens during
the G1 Phase?
2. synthesizes new organelles.
3. Normal cell functions
What happens during DNA Replication
the S Phase?
What happens during Additional cell growth
the G2 phase?
What happens during Mitosis and Cytokinesis
- Cell division occurs
the M phase?
What is Chromatin?
DNA that is completely unwound
“Spaghetti form” of DNA found
during G1 of Interphase
During what phase of the
cell cycle does cell
growth occur?
Interphase (G1)
What are the three parts G1, S, and G2 phases
of Interphase?
What is mitosis?
The division of the nuclear material
(nucleus)
What are sister
chromatids?
How are the two sides of
sister chromatids joined
together?
What are the building
blocks of DNA?
(Monomer)
2 identical copies of a
chromatid that have been
replicated and connected
together
centromere
Nucleotides
- Prophase
- Metaphase
- Anaphase
- Telophase
What are the four phases
of Mitosis?
What happens during
Prophase?
-The nucleolus and nuclear membrane
“break up” and temporarily disappear.
- Centrioles duplicate and separate to
opposite sides of the cell.
-The spindle fibers begin to form near the
centrioles.
What happens during
Metaphase?
-The chromosomes line up across the
center of the cell along the equator.
- Microtubules attach to the centromere
of each chromosome from both poles
of the spindle.
What happens during
Anaphase?
-The spindle fibers shorten.
-The centromeres are broken and the
sister chromatids separate.
-The chromosomes continue to move
until they have separated into two groups
near the poles of the spindle.
What happens during
Telophase?
-The nuclear envelope reforms around the
chromosomes.
- a nucleolus becomes visible in each
daughter nucleus
-Chromosomes begin to unwind back to
chromatin.
-The spindle breaks apart.
What is a histone?
The protein that DNA coils around
to start condensing to fit inside the
nucleus
What happens during
cytokinesis for animal
cells?
- The cell membrane is
pinched inward until the
cytoplasm is separated
into nearly equal halves.
What happens during
cytokinesis for plant
cells?
- A cell plate is formed in
the center of the cell and
grows outward to
separate the two cells.
What is the major
- mitosis is asexual
function of mitosis for reproduction so a new
unicellular organisms? organism is created.
1. Mitosis increases the
What is the major
function of mitosis for number of cells
multi-cellular organisms? 2. help the organism grow
3. replace dying cells.
What is this
phase and
what is
happening?
Interphase G1, S, G2,
•Cell growth, normal cell functions,
and replication of DNA and
organelles.
What is this
phase and
what is
happening?
Prophase
-The nucleolus and nuclear membrane “break up”
and temporarily disappear.
- Centrioles duplicate and separate to opposite
sides of the cell.
-Sister chromatids are held together by
centromeres
-The spindle fibers begin to form near the
centrioles.
What is this
phase and
what is
happening?
Metaphase
-The sister chromatids line up across the
center of the cell (equator)
- Spindles attach to the centromere of each
chromosome from both poles of the spindle.
What is this
phase and
what is
happening?
Anaphase
What is this
phase and
what is
happening?
Telophase
-The nuclear envelope reforms around the
chromosomes.
-Chromosomes begin to unwind back to
chromatin.
- a nucleolus becomes visible in each daughter
nucleus
-The spindle breaks apart.
-The centromeres are broken and the sister
chromatids separate.
-Spindle fibers shorten
-The chromatids continue to move until they have
separated into two groups near the poles of the
spindle.
What is the role of the
mitotic spindle (spindle
fibers) in mitosis?
To line up and divide the
chromosomes
What is the role of the
centrioles in animal
cells?
To divide the chromosomes during
mitosis