4. Why is cell division important?
•
•
•
To heal cuts, sores, and wounds.
Grow and Develop!
Even after growth ends cell division is
important to make new cells to
replace old cells!
Did you know?
Billions of blood cells are replaced daily!
7. Interphase
Stage 1
Facts:
1. Interphase
Inter= between
Phase=stage
a. A cell spends most
of its life in the
stage.
The cell doubles in size
b. Hereditary material
(DNA) and
organelles are
copied (enough for
two cells).
c. The cell prepares
to divide into two
new cells
9. Mitosis (division of the nucleus)
stage 2
2. Mitosis
*Mitosis is a Greek
word that means
“thread”.
*The chromosomes
look like threads.
*The chromosomes
are now copied and
are called,
chromatids.
Facts:
a. This stage is when the
chromosomes separate.
b. Each cell gets a copy of
each chromosome.
***Meaning that every new
cell is identical to the
original cell!!!
c. happens in all body cells
and in many single celled
organisms
d. Two identical nuclei are
formed.
16. Cytokinesis: cell splitting into two
1. In animal cells, cell membrane pinches in
to divide the cytoplasm.
2. In plant cells, a cell plate forms to divide
the cytoplasm.
18. Why is mitosis so important?
1. For growth
2. For repair and replacement of cells
3. Provides a way for the genetic information to be
copied and passed on to the new cells.
19. Binary fission
1. Simple cell division in which one cell
splits into two
2. Used by bacteria (prokaryotic cells) for
reproduction
3. Cell grows, DNA is copied, DNA and its
copy separate, and the cell splits in two
20. In a nut shell…..
1. This is the process by which cells reproduce themselves.
______________
2. How do prokaryotic cells make more cells?
___________________
3. What are the 3 stages eukaryotic cells go through to make
more cells?
___________,__________,_____________
4. Mitosis is the division of the _____________.
5. A human cell has 46 chromosomes. How many does the
cell have after cell division?
____________.
6. Upon completion of cell division are the new cells identical
to the parent cell? explain
21. Meiosis
• Two nuclear divisions
produce sex cells
(sperm and egg) with
exactly half of the
chromosomes of the
parent cell
• Only happens to
make cells for sexual
reproduction (Oh my!)
24. The significant difference!
• Mitosis
• Meiosis
• (My toe, sis!)
• Makes body cells.
• (Oh my! myOsis)
• Makes sex cells, sperm
and egg
• New cells have half of
each set of
chromosomes
• New cells have the
exact same number
of chromosomes as
the old cell
25. Review:
• What is the cell cycle?
• How are mitosis and meiosis alike? How
are they different?
• What process makes new body cells?
• What process makes reproductive cells?
• How does a bacterium reproduce?
• When does cytokinesis occur?
• How is cytokinesis different in plant and
animal cells?
27. Meiosis
i = how i was created!
• Two nuclear divisions
• Produce or make:
1. Sex cells (sperm and
egg)
2. The sex cells have half
of the chromosomes of
the parent cell -23
3. This happens to make
cells for sexual
reproduction (Oh my!)
28. • Sex Cell
• Egg or sperm
• Sex Chromosome
• Thread-like
chromosome that
carries the genes
that determine the
sex of the offspring.
• XX=girl
• XY=boy
30. Comparison
Mitosis and Meiosis
• Mitosis
• Meiosis
• (My toe, sis!)
• Makes body cells.
• New cells have the same
number of
chromosomes as the
original cell. IDENTICAL
• (i was made this way!!)
• Makes sex cells.
• New cells have half of
the number of
chromosomes as the
original.
• New cells are identical
to the original cell
• No two sperm or egg
cells are ever exactly
alike.
•
Meaning:
Skin cells make skin cells,
bone cells make bone cells,
etc.
• Offspring or babies will be
unique!
31.
32.
33. 1. What is the cell division that produces
body cells that are identical?
2. Name 3 differences between mitosis and
meiosis?
3. What cell division makes gametes or sex
cells?
4. How does bacteria or prokaryotic cells
reproduce?
5. What happens during cytokinesis?
