Download Meiosis - CashmereScience101

Starter
1. What is the purpose of Meiosis?
2. How many daughter cells are
produced in Meiosis?
3. Are the daughter cells identical or
different?
4. What causes the daughter cells to be
different?
Meiosis
 Meiosis is a special type of cell division used
to produce sex cells (a.k.a. “gametes”)
 Only occurs in the sexual organs (e.g. testes
of men or the ovaries of women)
 From one parent cell, four genetically
different gametes are produced.
 Causes variation in the offspring because of
crossing over and independent assortment
1. Chromosomes
duplicate
92 chromosomes
2. Homologous
chromosome pairs
exchange pieces –
called “cross over”
92 chromosomes
Cross Over
3. Chromosomes line
up in the middle
4. Chromosomes get
pulled apart
Independent Assortment
5. The cell splits into
two daughter cells.
46 chromosomes
+
46 chromosomes
6. Two genetically
different daughter
cells are produced.
46 chromosomes
+
46 chromosomes
7. The chromosomes
inside each
daughter cell line
up in the middle in
a random way.
8. Chromosomes get
pulled apart.
9. Each daughter cell
splits into two.
10. Four daughter cells
with only half the
number of
chromosomes are
produced.
Sequence of Events
1. Chromosomes duplicates
2. The chromosomes cross over.
3. Chromosomes line up in the middle
4. Chromosomes get randomly pulled apart and
the parent cell splits into two daughter cells.
5. The chromosomes inside each daughter cell
line up in the middle then get pulled apart.
6. Each daughter cell splits, producing a total of
four daughter cells.
Meiosis
 Meiosis is a special type of cell division used
to produce sex cells (a.k.a. “gametes”)
 Only occurs in the sexual organs (e.g. testes
of men or the ovaries of women)
 From one parent cell, four genetically
different gametes are produced.
 Causes variation in the offspring because of
crossing over and independent assortment