MITOSIS NOTES
I.
Purpose
A.
B.
Cell Division: a process by which a cell divides into 2 NEW CELLS
1.
Original Cell = Parent Cell
2.
2 new cells = Daughter Cell
3.
Each copy cell is an exact copy of DNA and number of chromosomes
Why do we need cell division?
1.
Living things grow by producing more cells (cells DO NOT increase in
size to grow)
2.
Repair damage tissue
3.
Asexual Reproduction for some organisms (mostly unicellular);
cloning themselves
II.
DNA
A.
Located in the nucleus
1.
Non-dividing cell (Interphase): it is thread-like (think spaghetti) called
CHROMATIN
2.
Dividing cell (during Mitosis): it is like a bundle up “double coil” phone
cord forming Chromosomes
3.
III.
Chromosomes have 2 parts
a)
Chromatid (the “arms”)
b)
Centromere (the center)
Chromosomes
A.
Each species have a specific number and structure
1.
Human = 46 chromosomes (23 pairs)
2.
Dog = 78 chromosomes (39 pairs)
B.
IV.
3.
Goldfish = 94 chromosomes (47 pairs)
4.
Lettuce = 18 Chromosomes (9 pairs)
Each and EVERY cell in your body has 23 pairs of chromosomes
Mitosis
A.
B.
C.
D.
Interphase
1.
Happens before Mitosis Occurs
2.
90 percent of life cycle
3.
DNA doubles as chromatin at this time
Prophase
1.
1st stage of mitosis
2.
Chromosomes develop
Metaphase
1.
2nd stage of mitosis
2.
Meta = Middle
3.
Chromosomes Line Up across the diameter of the cell
Anaphase
1.
3rd stage of Mitosis
2.
Ana = think Apart
3.
Chromosomes are pulled APART through centrioles shooting out
spindle fibers
E.
Telophase
1.
4th stage of Mitosis
2.
Telo = think Two
3.
Cytokinesis “splitting of the parent cell” into two daughter cells