Sex determination is the process by which an individual develops into a male or female based on their sex chromosomes. In humans, females have two X chromosomes (XX) while males have one X and one Y chromosome (XY). The presence of a Y chromosome triggers male development while its absence results in female development, with sex being governed by genes on the sex chromosomes. Human body cells normally contain 23 pairs of chromosomes, including 22 pairs of autosomes that do not determine sex and one pair of sex chromosomes that do signal sex determination.

1. SEX DETERMINATION
BY: MRS. PRECILLA C. STEPHEN

2. OBJECTIVE
• To understand the process of sex
determination.

3. WHAT IS SEX DETERMINATION
• Sex determination is the process of sex
differentiation by which whether a particular
individual will develop into male or female sex.
• The sex chromosomes are responsible for
determination of separate sexes.

4. • Sex expression is governed by
chromosomes and genes.

5. • In unisexual animals, chromosomes are of two
types, viz., autosomes and allosomes.
Autosomes – Chromosomes which do not differ in
morphology and number in male and female.
Allosomes or sex chromosomes – Chromosomes
which differ in morphology and number in male and
female and contain genes that determine sex.

6. Traditionally . The symbol designates male
And the symbol designates female.

7. • Human body cells have 46 chromosomes arranged in 23
pairs.
• There are 22 pairs of autosomes and one pair of sex
chromosomes (allosomes).
• Female have a perfect pair of sex chromosome XX.
• Male have mismatches pair of sex chromosome XY.
• Both male and female contain equal amount of
chromosome 23 pair
• Out of 23 pair: 22 pairs are autosomes
1 pair is sex chromosome.

8. • Only have half of the DNA of a body cell; they
are ‘haploid’. Instead of 46 chromosomes, so
23 pairs, they just have 23 chromosomes in
total. 22 autosomes and one sex chromosome,
or allosomes. An ovum will always have an X
chromosome but the sperm will have an X or a
Y.

13. Thank You