Transcript Meiosis

Meiosis &
Mitosis
By: Alexier Soto-Carlo,
Corey cheatem, & Derrick
Jones
Period: 6 Science
Mr. White
This is the process of Meiosis.
Before Meiosis
• Before meiosis begins, every
chrOmosome in the parent cellis
copied. Centromeres hold the two
chromatids together.
Meiosis i
• THE CHROMOSOME PAIRS LINE UP IN THE
CENTER OF THE CELL.
Meiosis I (b)
• The pairs separate and move to
opposite ends of the cell.
Meiosis I (c)
• Two cells form, each with half the
number of chromosomes. Each
chromosome still has two
chromatids.
Meiosis ii
• The chromosomes with their two
chromatids move to the center of
the cell.
Meiosis ii (b)
• The centromeres split, and the
chromatids separate. Single
chromatids move to opposite ends
of the cell.
End of Meiosis
• Four sex cells have been produced.
Each cell has only half the number
of chromosomes that the parent
cell had at the beginning of
meiosis. Each cell has only one
chromosome from each original
pair.
MITOSIS
This is the process of Mitosis.
Interphrase
• The cell grows To iT’s maTure size,
makes a copy of iT’s D.N.a., aND
prepares to divide into two cells.
Two cylindrical Structure called
centrioles are also copied.
Mitosis: Prophase
• Chromatin in the nucleus condenses
to form chromosomes. The pairs of
cenrtioles move to opposite sides
of the nucleus. Spindle fibers form
a bridge between the ends of the
cell. The nuclear envelope breaks
down.
Mitosis: Metaphase
• The chromosomes line up across the
center of the cell. Each
chromosome attaches to a spindle
fiber aT iT’s ceNTromere.
MITOSIS: aNAPHASE
• The centromeres split. The two
chromatids separate. One chromatid is
drawn by its spindle fiber to one end of
the cell. The other chromatid moves to
the opposite end. The cell stretches out
as the opposite ends are pushed apart.
Mitosis: Telophase
• The chromosomes begin to stretch
out and lose their rodlike
appearance. A new nuclear
envelope forms around each region
of chromosomes.
Cytokinesis
• The cell membrane pinches in
around the middle of the cell. The
cell splits in two. Each daughter
cell ends up with an identical set
of chromosomes and about half
the organelles.
The End