What is meant pleiotropy
Answers
Explanation:
the production by a single gene of two or more apparently unrelated effects.
Answer:
(1) When a single gene controls two or more different traits, it is called a pleiotropic gene and the phenomenon is known as pleiotropy or pleiotropism.
(2) The pleio iropic ratio is always 1 : 2 instead of normal 3
(3) Sickle-cell anaemia is caused by the gene HbS. The healthy or normal gene which is dominant is Hb. The heterozygotesor carriers i.e., HbHbs show anaemia as there is deficiency of haemoglobin due to sickling of RBCs. Abnormally low Concenuration of Oxygen can cause sickling of RBCs.
(4) The homozygo tes possessing the recessive gene Hbs die because of fatal anaemia because the gene for sickle-cell anaemia is lethal in homo zygousnconditiom and causes slckle-cell rait in heterozygous carrier
(5) Thus a single gene produces two different Copresstions,
(6) When two carriers are married they will produce normal carriers and Sickle-cell anaemic children in the ratio of 1 :2:1. Out of these three children sickle-cell anaemic child will die leaving the ratio 1 :2 instead of 3: