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CHAPTER 22 – CELL REPRODUCTION

MITOSIS – A type of cell reproduction in which 2 identical cells are made from 1 cell.

2 Stages of Mitosis:

All __________ cells are formed and regenerated by ________________. This process occurs throughout life.

Life Spans of different human body cells:

Brain cells - _______________              Muscle cells - _______________

Red Blood Cells - ___________                Platelets - __________________

Stomach Lining Cells - _____________      Liver Cells - _________________

Intestine Lining Cells - _____________      Skin Cells - _________________

Mitosis works similar to how a photocopy machine works:

Start with a picture

End with 2 of the exact same copy of the original

What happens BEFORE Mitosis occurs?

Chromosome number ____________________ (Example 4->8)

Steps of Mitosis

 Step One

Step Two

Step Three

Step Four

Benefits of Mitosis

• Helps us grow by ____________________________________________
• Replaces cells lost by _________________________________________

Differences between Plant Cell Mitosis & Animal Cell Mitosis

MEIOSIS – A kind of cell reproduction that forms sperm and eggs (sex cells).

_________________________ - reproductive cells produced in sex organs.

Includes:

• ___________________ cells formed in ___________________

• ___________________ cells formed in ___________________ 

Meiosis involves __________________________ resulting in _______________________.

___________________ - A cell containing half the number of chromosomes as a body cell.

Example:

Refer to fig. 22-7 on page 471:

Steps of Meiosis

Step One

Step Two

Step Three

Step Four

Step Five

Step Six

Sperm, Eggs & Fertilization

Refer to figure 22-10:

When sperm (haploid) fertilizes an egg (haploid), the chromosome number becomes ________________. 

Changes in the Rate of Mitosis are caused by:

________________________ - Rate of cell division, or mitosis, slows down in body cells.

________________________ - A disease in which body cells reproduce at an abnormally fast rate.

 Causes of Cancer 

• ___________________________ - EDTA, formaldehyde cause mutations in DNA
• ___________________________ - Exposure to the sun (Ultraviolet light) causes mutations in DNA
• ___________________________ - Cause mistakes in DNA replication.