Topics to be covered :-

1. Chromosomal disorder

• Down’s syndrome
• Klinefelter’s syndrome
• Turner’s syndrome

2. Question time

CHROMOSOMAL DISORDER

• Disorders can also be created by imbalance in chromosome number and chromosomal rearrangement these are called as
  chromosomal disorders.
• Down’s syndrome, Klinefelter’s syndrome and Turner’s syndrome are common example of chromosomal disorders.

Down’s syndrome

It was first described in 1866 by Langdon down.
This disorder develops due to trisomy of chromosome number 21.

Features :-

Individual is short
Small round head
Furrowed tongue
Partially open mouth
Broad palm
Big and wrinkled tongue
Physical, mental development is retarted.

Klinefelter`s Syndrome

• It is called due to presence of an additional copy ✓ of X- chromosomes on sex chromosomes in males and resulting into 44 + XXY type chromosomes.
• Such a persons are sterile males with overall.
• Have masculine development.
• Some female characteristics like feminine pitched voice, development of breast.

Turner’s Syndrome

• The disorders is due to monosomy (2n-1).
• It is caused in females due to absence of One X- Chromosomes
• The female with this syndrome has XO Sex chromosomes

Symptoms

1. The Infected Individuals are sterile
3. Packs Female secondary sexual characteristic. Poor development of breast.