Zoology - Principles of Inheritance and Variation Question with Solution | TestHub
Pick out the correct statements:
(i) Colour blindness is a sex-linked recessive gene disorder
(ii) Klinefelter's syndrome is 18th chromosomal trisomy
(iii) Phenylketonuria is an autosomal dominant gene disorder.
(iv) Down’s syndrome is due to aneuploidy
Options:
Answer:
Solution:
Colour blindness is usually a genetic condition. Red/green and blue colour blindness is usually passed down from parents to offsprings. The gene which is responsible for the condition is carried on the X chromosome.
Edward syndrome is a genetic disorder caused by the presence of all or part of an extra 18th chromosome. The majority of people with the syndrome die during the fetal stage; infants who survive experience serious defects and commonly live for short periods of time
Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example, a human cell having 45 or 47 chromosomes instead of the usual 46. Down’s syndrome is due to aneuploidy with 47 chromosomes.
Phenylketonuria is an autosomal recessive gene disorder.
