1. Lesson 4 – Genetics for Science 10
Cell Cycle & Mitosis
Lesson 4 – Genetics for Science 10

2. Cell Cycle describes the life of a cell from the time it is first formed from a dividing parent cell until its own division into two cells!
Key Terms of Genetic Material:
Genome: all the genes of an organism
Chromatin: thread-like structure composed of DNA and protein
Chromosomes: tightly wound packages of chromatin (ready for cell division)
In your nucleus, you have 2 sets of chromosomes:
23 pairs of chromosomes (46 individual chromosomes) -1 from dad, the other from mom
Because you have 2 complete sets of chromosomes, you are diploid (2n); where n = 23 (number of pairs)

3. BLIND KAHOOT
Kahoot is often used as a review, today we are going to use it to learn. Follow along with the handout

4. Chromatids: one of two distinct strands that make up a chromosome
Centromere: holds together each pair of chromatids
Somatic Cells: body cells (diploid)
Gametes: sex cells (haploid) e.g. sperm and eggs

5. Why must cells divide?
All cells must divide when they get too large! The surface area to volume ratio becomes too large that the cell can no longer function properly.
Why? Surface allows nutrients in and waste out, not enough surface means can’t support the needs of the volume
Before the nucleus can divide, it needs to make a duplicate copy of DNA

6. The Cell Cycle
Two Parts: Interphase and Division

7. Interphase INTERPHASE: cell growth & DNA Replication
makes up 90% of a cell’s life, which is spent growing, functioning, duplicating its organelles and DNA

8. 2: Cell Division
Mitosis: the division of the nucleus; results in 2 identical nuclei
Consists of 4 phases:
Prophase:
each chromosome and its copy (sister chromatids) join up
nucleolus becomes visible
nuclear membrane breaks down
centrioles move to opposite ends and form spindle fibres
b. Metaphase: Sister chromatids line up along center of spindle fibres
c. Anaphase: Sister chromatids are pulled apart to opposite ends of the poles
d. Telophase: Nuclear membranes form around 2 new sets of chromosomes, spindle disappears, chromosomes lengthen and get thinner, nucleoli reappear

9. 2: Cell Division - continues
ii. Cytokinesis: division of organelles and cytoplasm into equal halves
Animal cells: cell membrane pinches inward (furrow) until cell divides into two
Plant cells: cell wall forms a cell plate which divides the 2 nuclei
End result: 2 identical daughter cells!

10. Video: Mitosis—The Amazing Cell Process That Uses Division to Multiply