Question
Which of the following disorders is caused by
nondisjunction of sex chromosomes?Solution
Turner syndrome is a genetic disorder caused by the nondisjunction (failure of chromosomes to separate properly) of sex chromosomes during meiosis. It results in a monosomy (45, X), where affected individuals have only one X chromosome instead of two (XX in females). It occurs only in females and leads to symptoms such as short stature, underdeveloped ovaries, and infertility. (1) Cystic fibrosis – An autosomal recessive disorder caused by mutations in the CFTR gene (not related to sex chromosomes). (2) Hemophilia – A sex-linked recessive disorder caused by mutations in clotting factor genes on the X chromosome, but not due to nondisjunction. (4) Sickle cell anemia – A single-gene mutation disorder affecting hemoglobin, inherited in an autosomal recessive pattern, not due to sex chromosome nondisjunction.
“Hopper burn” is caused by brown plant hopper in _________ crop:
An extreme modification in the order Diptera, where hind wings are reduced to nubs used for balance and direction during flight is
Deficiency of which mineral causes interveinal chlorosis of older leaves in which the veins remain green but the area between them turns yellow
Jute fibre is obtained from
De suckering is practiced in
The Ranikhet disease affects:Â
Leaf curl disease of cotton is due toÂ
Carbonation weathering involves reactions with:
Polyembryony occurs in
Which of the following is a measure to promote the export of organic products under India's Agricultural Export Policy?