Download Karyotype

EQ: How can I use a karyotype to determine
if a person has a genetic disorder?
To study the chromosomes in a nucleus, scientists organize
the chromosomes into a karyotype.
Karyotype: a picture of the chromosomes in a cell. The
chromosome pairs are arranged in descending order of size.
(start big, get small)
20
pairs
19
pairs
So, how many chromosomes do we have? 23 pairs or 46 total
This is considered to be a diploid cell because it has all 23
pairs of chromosomes—a complete set for a human.
23
pairs
In a karyotype, the 1st 22 pairs of chromosomes are called
AUTOSOMES.
The 23rd pair are called SEX CHROMOSOMES.
So, if this happy couple was to have a
baby – how many chromosomes will
the baby have?
If the husband gives the baby 46
chromosomes and she gives 46
chromosomes, that’s 92 chromosomes
in our baby!?! That’s not human!!
He can ONLY give HALF of his
chromosomes, and she can only give
HALF. Then the baby will have a
total of 46.
~ 23 from Mom, 23 from Dad ~
What’s wrong with this Karyotype?
Is this Karyotype a Male or Female
Down’s Syndrome
• Trisomy 21 – 3
chromosomes at
location #21
• A result of nondisjunction
• Decreased mental
capability
• Flat face/features
• Wider necks
• Shorter stature