Download How does Meiosis differ from Mitosis

How does Meiosis differ
from Mitosis
Students will know they are successful when
they can………..
1. Explain the reduction of chromosome
number that occurs during meiosis
2. Recognize and summarize the stages of
meiosis
3. Analyze the importance of meiosis in
providing genetic variation
Chromosomes and Chromosome
Number
Chomosomes contain segments called genes
that are used to control the production of
proteins.
Homologous Chromosomes
Each body cell has 46 Chromosomes (23 pairs),
23 from mom and 23 from dad. Pairs of
Chromosomes are called Homologous.
Meiosis
Meiosis: Is a type of cell division that reduces
the number of chromosomes, that occurs in
the reproductive cells of sexually reproducing
organisms. It does this by going through 2
separate cell divisions, Meiosis 1 and Meiosis
2.
Comparing Mitosis to Meiosis 1
During Mitotic
Metaphase each
individual chromosome
lines up along the
metaphase plate
During Meiosis Prophase 1,
pairs of homologous
chromosomes line up
together, called synapsis.
Crossing Over and
Recombination
Crossing over:
is a process during
prophase 1 in which
chromosomal segments
are exchanged between
a pair of homologous
chromosomes, and
increases the genetic
variation of the gametes
The cell then Divides, and Meiosis 1 is
finished, and ready for a second cell
division called Meiosis 2.
Meiosis 2
During Meiosis 2 the cell once again goes
through all the stages; prophase 2, metaphase
2, anaphase 2, telophase 2.
But the chromosomes have not replicated again.
The result is 4 daughter cells each with
their own unique genetic variation