Chromosomes: Extra Practice
First, lets go back and discuss diploid and
haploid…then we’ll do some practice
• Diploid Cells = Cells with
the full set of
chromosomes (2n)
– Paired chromosomes
• Half of our chromosomes
come from each parent
(23 from each parent)
• Somatic (non-sex) cells
are diploid
• Created by mitosis
• Ex: Skin, Muscle, Nerve,
Blood Cells
What is the human diploid chromosome number?
Remember…Diploid = total number of chromosomes
Answer = 46
What is the human somatic chromosome number?
Remember…Somatic cells are non-sex cells…
…Somatic cells are diploid…
…Diploid cells have the full set of chromosomes
Answer = 46
How many chromosomes are in brain cells?
Remember…Brain cells are non-sex cells…
…Somatic cells are non-sex cells…
…Somatic cells are diploid…
…Diploid cells have the full set of chromosomes
Answer = 46
• Haploid Cells = Cells with ½ the
total number of chromosomes (n)
• Gametes (sex cells) are the only
haploid cells
– Ex: Sperm, Egg, Pollen
• Chromosome number is reduced
by meiosis
• How do humans get 46
chromosomes?
Haploid sperm cell (23) + Haploid egg cell (23)
= Diploid zygote (46)
I’m half
mom and
half dad.
These chromosomes are
in the egg cell of mom.
These chromosomes are
in the sperm cell of dad.
What is the human haploid chromosome number?
Remember…Haploid = half number of chromosomes
Answer = 23 chromosomes
What is the human gamete chromosome number?
Remember…Gamete cells are sex cells…
…Sex cells are haploid…
…Haploid cells have ½ the set of chromosomes
Answer = 23
How many chromosomes are in female egg cells?
Remember…Egg cells are sex cells…
…Sex cells are gametes…
…Gamete cells are haploid…
…Haploid cells have ½ the set of chromosomes
Answer = 23
• What is the diploid chromosome number?
42
• What is the haploid chromosome number?
21
• How many chromosomes would be in somatic cells?
42
• How many chromosomes would be in brain cells?
42
• How many chromosomes would be in gamete cells?
21
• How many chromosomes would be in muscle cells?
42
• How many chromosomes would be in sperm cells?
21
• How many chromosomes would be in egg cells?
0- not female!
• Is this a male or female rat?
male
Is the organism male or female?
male
__________
What is the chromosome # in….
24
Haploid cells? ________
48
Diploid cells? ________
48
In white blood cells? _______
24
In sperm cells? ____________
48
In somatic cells? ___________
24
In gamete cells? ___________
48
In muscle cells? ___________
0- not female!
In egg cells? ______________
48
In a zygote cell? ___________
Notice….24 pairs of chromosomes