Download How are new cells made? - Social Circle City Schools

Mitosis and Meiosis
Making new cells….
Body Cells= Somatic Cells
Sex Cells
 Mitosis
 Meiosis
 Process used to make new
 Process used to make new sex
body cells
 Body cells are the cells found
in the human body
 Examples: heart, lung, skin,
muscle, etc.
 Human Body has 46
chromosomes in each body
cell




cells
Sex cells are sperm and egg.
Males= sperm=xy
Females = eggs=xx
Sex cells have 23
chromosomes each
23 sperm + 23 egg = 46
human body cells
Mitosis and Meiosis
Making new
body cells
begins with….
Stage 1: Interphase
1. The cell grows to
its mature size.
2. The cell makes a
copy of its DNA
called replication.
3. The cell prepares
to divide into two
cells.
Page 96
Cell Division
Cell Cycle
Three stages:
1. Interphase
2. Mitosis
3. Cytokinesis
Stage Two:
Mitosis:
Prophase
-chromatin in the
nucleus condenses
to form
chromosomes
-two pairs of
centrioles move
to opposite sides
of the nucleus
-nuclear envelope
breaks down
(page 97)
Mitosis:
Metaphase
-Chromosomes line up
across the center
(middle) of the cell.
-Each chromosome
attaches to a spindle
fiber at the centromere
-Page 98 -99
HINT:
Remember this
by thinking….
Metaphase starts with an
“M” and so does the word
middle.
Mitosis:
Anaphase
-centromeres split
-chromatids separate
-each chromatid becomes
a new chromosome
-chromosomes move to
opposite ends of cell
-pages 98 - 99
HINT: Anaphase starts
with an “A”, and the word
“apart” does also.
Mitosis:
Telophase
-chromosomes
begin
to stretch out
-new nuclear envelope
forms around each
region of
chromosomes
-pages 98 -99
Stage Three:
Cytokinesis
-Cell membrane pinches
in around middle of the
cell
-Cell splits in two
-Each daughter cell ends
up with an identical set
of chromosomes and
about half the
organelles.
page 100
-