Objectives
Differentiate between somatic (body) cells and
gametes.
Compare and contrast diploid and haploid.
A. Somatic Cells- Also called body cells, make up most of
your body tissues and organs.
Examples: skin, blood, kidney, spleen, eyeballs
1. DNA in your body cells ARE NOT passed on to
your children.
B. Gametes- Also called sex cells. These are cells in the
reproductive organs such as the ovaries and the testes.
Examples: Sperm (male) and Egg (female)
2. DNA in your gametes CAN BE passed to your
children.
What cell type makes up the brain:
Somatic Cells or Body Cells?
A.
Somatic cells (body cells) and gametes have a
different number of chromosomes.
1. In humans, somatic cells have 46 individual
chromosomes.
2. In humans, gametes have 23 individual
chromosomes
How many chromosomes are in a skin cell?
Liver cell?
How many chromosomes are in a sperm cell?
Egg cell?
1. Each of your body cells contain 23 pairs.
2. Somatic cells are diploid. Diploid means the cell has
two copies of chromosome; one from Mom and one
from Dad
3. To find the diploid number, use the following
formula 2(n)=diploid number
n=number of chromosomes
2(23)=46
A fruit fly has 4 pairs chromosomes.
What is the diploid number of the fruit fly?
Yeast has 16 pairs of chromosomes.
What is the diploid number of the yeast?
1.
Gametes have 23 individual chromosomes. This is
half of the somatic cell.
2. Gametes are haploid. Haploid means that a cell has
only one copy of each chromosome.
3. Haploid is represented by (n).
4. To find the haploid number, use the following
formula 2(n)=46 n=23
A fruit fly has 8 chromosomes.
What is the haploid number of the fruit fly?
Yeast has 32 chromosomes.
What is the haploid number of the yeast?
1. What cells in living organisms are diploid?
2. What cells in living organisms are haploid?
3. What does the symbol 2n represent?
4. What does the symbol n represent?
5. The 2n number for dogs in 78. How many chromosomes would
you find in a dog’s blood cell?
6. How many chromosomes would you find in a dog’s sperm cell?
7. If the sperm cell of a fruit fly has 4 chromosomes, then the
number of chromosomes in each body cell is:
a) 2
b) 4
c) 6
d) 8
e) 16
8. Of the following cells, the only one to have the haploid number
of chromosomes is:
a) skin
b)muscle c) nerve
d) blood
e) egg