Transcript mitosis spring 2013

Mitosis, Significance to
unicellular and multicellular
organisms, Chromosomes
Significance of cell reproduction to
multicellular & unicellular organisms
1. Unicellular:
reproduce by cell
division. Also
called binary
fission.
2. Multicellular- processes of growth and
repair upon cell division, also the
production of sex cells.
Describe
chromosomes
1. Carriers of
genetic material
found in nucleus
2. Made up of
DNA
3. Information
is copied and
passed to
future
generations
4. Usually exist as chromatin
a. long, winding strands
which condense into
chromosomes before
dividing
5. Human chromosome number is 46 in
body cells, 23 in sex cells
The Cell Cycle
1. The cell cycle is a sequence of
growth and division of a cell
Made up of 2 distinct stages:
A. Interphase: growth period where
DNA is copied
B. Mitosis: dividing period producing 2
new cells
Interphase
7 Hours
11 Hours
DNA
synthesis
Rapid growth,
centrioles
replicate
3 Hours
Growth &
final prep
P
T
A
M
Mitosis-1 hour
Interphase- the first part of the cell
cycle
1. Also called the resting
stage
2. Cells make ATP
3. The cell repair
themselves
4. Make proteins
5. Make new organelles
6. Copying new
chromosomes(DNA)
Mitosis is the division of the cytoplasm
followed by cell division. There are 4
stages of mitosis.
Mitosis
Prophase
The following events
occur:
1. Chromatin coils to
form short rods
2. The 2 copies
(chromatids) join to
form chromosomesheld together by
centromere
3. Nuclear membrane
disappears
4. Centrioles move
to opposite ends of
the cell
5. Spindle formshelps pull
chromosomes apart
& are attached to
centrioles
centrioles
Metaphase
1. Chromosomes attach to spindle fibers
2. Chromosomes line up in the middle of
the cell(equator).
Anaphase
1. Centromeres split apart
2. Chromatids pairs split apart and begin
to move to opposite ends(poles).
Telophase
1. Chromatids reach opposite poles.
2. Chromatids begin uncoiling to form chromatin again
3. Spindle breaks down
4. Nucleolus and nuclear membrane reappear
5. Plasma membrane begins to pinch in
Division of Cytoplasm-cytokinesis
In animals-the cell
pinches in along
the equator
In plants- the cell
plate forms down
the equator of the
cell
Quiz #1
Mitosis
1. The sequence of events of cell growth & division is
called __________.
a. Mitosis cycle b. cell cycle c. division cycle
2. __________ is when the cell prepares itself by copying
DNA, repairing itself & making new organelles.
a. Metaphase b. prophase c. interphase d. telophase
3. Name the phase in which chromosomes are lined up at
the equator.
a. Anaphase b. telophase c. cytokinesis d.metaphase
4. As the cytoplasm divides, what forms in plants down
the equator of the cell?
a. chromatids
b. chromosomes
c. cell plate
5. Identify the correct phase of the cell cycle & mitosis.
a. interphase, prophase, metaphase, anaphase, telophase
b. prophase, metaphse, interphase, anaphase, telophase
c. telophase, metaphase, anaphase, interphase, prophase
d. telophase anaphase, metaphase, prophase, interphase