Download Haploid Cells

• Defined: Tightly coiled
DNA
• Form when cells divide
– Chromosomes created
for the new cells
• 2 Parts:
– 1) Chromatids: two
identical parts of a
chromosome
– 2) Centromere:
Joins chromatids
together
• Defined: Picture of an
individuals chromosomes
– Help identify sex &
chromosome defects
• Size of final pair identifies
sex
– Same size: XX = female
– Different size: XY = male
• Normal human will have
46 chromosomes
Down Syndrome: What’s Wrong?
• Writing notation:
– 1st: total
chromosome #
– 2nd: Sex
chromosomes
– 3rd: extra or
missing
• Down Syndrome
47, XY, +21
Turner’s Syndrome: What’s Wrong?
• Write the notation
for Turner’s
Syndrome.
45, X, -23
or
45, XO, -23
Patau’s Syndrome: What’s Wrong?
• Write the notation
for Patau’s
Syndrome.
47, XY, +13
Klinefelter’s Syndrome: What’s Wrong?
• Write the notation
for Klinefelter’s
Syndrome.
47, XXY, +23
• Diploid Cells = Cells
with the full set of
chromosomes
– 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
• Haploid Cells = Cells with ½ the
total number of chromosomes
• Gametes (sex cells) are the only
haploid cells
– Ex: Sperm, Egg, Pollen
• Created by meiosis
– Chromosome number reduced by
1/2
• How do humans get 46
chromosomes?
Haploid sperm cell (23) + Haploid egg cell (23) = Diploid zygote (46)
Diploid Karyotype
Haploid Karyotype
Because diploid cells have the full set of chromosomes, you will see
chromosomes paired.
• Is this a male or female rat?
male
• 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 egg cells?
21
• How many chromosomes would be in muscle cells?
42
• How many chromosomes would be in sperm cells?
21
Review
• 1) What is the difference between chromatin, chromatids, and chromosomes?
• 2) Name the location where chromatids connect.
• 3) Examine the karyotype.
– What the haploid number?
– Diploid number?
– Somatic number?
– Gamete number?
• 4) Which of the following cells are created by mitosis?
Skin Nerve Sperm Brain Kidney Stomach Pollen
• 5) Which of the following cells are created by meiosis?
Skin Nerve Sperm Brain Kidney Stomach Pollen
• 6) Which of the following cells are haploid?
Skin Nerve Sperm Brain Kidney Stomach Pollen
• 7) Which of the following cells are diploid?
Skin Nerve Sperm Brain Kidney Stomach Pollen