The cell is going to divide!!??

1
The cell is going to divide!!??
2

• www.bioweb.uncc.edu/biol1110/stages.htm
• www.biology.arizona.edu/cell_bio/tutorials/cell_cy
  cle/cells1.html
• science.nhmccd.edu/biol/mitosis/pmitosis.html

3
Levels of Organization

• Cell (animal or plant Body or sex
  cell)
• Nucleus (Contains chromosomes)
• Chromosomes (divide during cell division)
• Gene (Segment of Chromosome)
• DNA (Contains genetic
  information)

4
(No Transcript)
5
Vocabulary

• Gamete sex cells sperm or egg
• Fusion of gametes forms a zygote.
• A zygote always has a full or diploid (2n) number
  of chromosomes

6

• Each species has a characteristic number of
  chromosomes.
• Diploid (2n) number includes two sets of
  chromosomes of each type.
• Found in all the non-sex cells or autosomes of an
  organism's body (with a few exceptions).
• Examples include humans (46), crayfish (200),
  etc.
• Haploid (n) number contains one of each kind of
  chromosome.
• In the life cycle of many animals, only sperm and
  egg cells(sex cells) have the haploid number.
• Examples include humans (23), crayfish (100),
  etc.

7
Types of Chromosomes

• Autosomes Body chromosomes or non sex
  chromosomes ( humans have 44 or 22 pairs)
• Sex Chromosomes XX or XY (23rd pair for humans)
  determines the sex of the offspring

8
(No Transcript)
9
Mitosisthe division of body cells
Daughter cells are identical to Parent cell
Parent cell 46 chromosomes
Daughter cell 46 chromosomes
Daughter cell 46 chromosomes
10
(No Transcript)
11
Remember Cell size?

• 1cm
• If your cells
• Were this size
• Then

12

The Cell Cycle
13
THE CELL CYCLE Interphase Mitosis
Cytokinesis
14
Interphase

• Time in between cell division (mitosis)
• G1 Cell growth
• S DNA Replication
• G2 Prep for mitosis

15
Prophase
Centromeres produce spindle fibers

• 1. Chromosomes appear condensed
• 2. Nuclear envelope and nucleus disappears
• 3. Centrioles separate to the poles of the cell
• 4. Chromosome (at their centromeres)attach to
  spindle fibers

16
(No Transcript)
17
Metaphase

• 1. Chromosomes line up in the equator (center) of
  the cell.
• (Spindle fibers help move chromosomes thru cell)

18
(No Transcript)
19
Anaphase

• 1. The centromere splits and chromatids
  separate.
• 2. Chromatids move to the poles of the cell

20
(No Transcript)
21
Telophase

• 1. Chromatids start to become diffuse
  (chromatin)
• 2. The nuclear envelope starts to reform
• 3. Nucleolus reforms
• 4. Spindle breaks apart
• 5. Cells begins splitting

22
(No Transcript)
23
Cytokinesis

• NOT a phase of mitosis
• It is a process of the cytoplasm dividing after
• mitosis.

24
(No Transcript)
25
(No Transcript)
26
Interphase

• 2 new cells are formed
• Identical to the original parent cell

27
THE CELL CYCLE Interphase Mitosis
Cytokinesis
28
Plant Mitosis
Onion Root Tip Cells
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
The Cell Cycle

41
Cell Division Prokaryotes

• The Prokaryotic Chromosome
• Chromosome consists of nucleoid (an
  irregularly-shaped region, electron-dense, and
  not enclosed by a membrane.
• Chromosome, when stretched out, is a circular
  loop attached to the inside of the plasma
  membrane about 1,000 times the length of the
  cell.

42

• 3. When cell is approximately twice its original
  length, the plasma membrane grows inward, a new
  cell wall forms dividing the cell into two
  approximately equal daughter cells.
• 4. Generation times of Escherichia coli is 20
  minutes most bacteria need up to one hour to a
  day.

43
(No Transcript)