Karyotyping is a method used to visualize an organism's chromosomes in homologous pairs, which aids in identifying genetic abnormalities. The process involves preparing karyotypes from cultured white blood cells during mitosis, where chromosomes are stained, photographed, and arranged. It reveals information such as chromosome number, sex chromosome content, and the presence of structural abnormalities, with specific examples including human male and female karyotypes, polyploidy, and common trisomy conditions.

2. KARYOTYPING
 A karyotype is a picture of the chromosomes in an organism arranged
in homologous pairs according to shape and size. Or it is mapping of
chromosomes.
 Karyotyping is important to know genetic abnormalities.

3. Preparing a
Karyotype
 Karyotypes are prepared from nuclei of cultured white blood cells.
 These cells are undergoing mitosis and when they reach metaphase,
colchicine is added which arrests cell division in metaphase (where
chromosomes are well distinct).

4. Preparing a
Karyotype
 Chromosomes are stained and photographed under a microscope.
 Chromosomes are cut up & arranged into homologous pairs
according to shape and size.

6. Metaphase chromosomes

7. Information Obtained from a Karyotype
1. Number of chromosomes
2. Sex chromosome content
3. Presence or absence of individual chromosomes
4. Nature and extent of large structural abnormalities

8. The karyotype of a human male
consists of 22 pairs of autosomes
(44 chromosomes) plus a single
X and a single Y chromosome.
Notice: change in size of
different chromosomes.

9. The karyotype of a human
female consists of 22 pairs of
autosomes (44 chromosomes)
plus 2 X chromosomes.
Notice: change in size of
different chromosomes.

10. Polyploidy: Triploid
69 chromosomes with XXX
sex chromosomes.
Notice: each set of
chromosomes consists of 3
chromosomes instead of
two

11. Polyploidy: Tetraploid
92 chromosomes with
XXYY sex chromosomes.
Notice: each set of
chromosomes consists of 4
chromosomes instead of
two

12. Trisomy of autosomes
:
Karyotype of aborted
baby showing trisomy of
chromosome number 16.
This pregnancy will not
complete, and abortion
occur

13. Karyotype of a male
patient with trisomy of
chromosome number 22.
Trisomy of autosomes
:

14. Monosomy of sex chromosome
:
Karyotype of female
patient with Turner’s
syndrome showing 22
pairs of autosomes (44)
and one X chromosome.

15. Trisomy of sex chromosome
:
Karyotype of male
patient with Klinefelter
syndrome showing 22
pairs of autosomes (44)
+ two X and one Y
chromosomes.

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