Multiple Choice Questions9: 3: 3: 1 ratio is modified to 9 : 7 ratio due to
complementary gene
epistatic gene
hypostatic gene
supplementary gene
The map distance between the genes A and B is 3 units, between B and C is 10 units and between C and A is 7 units. The order of the genes in a linkage map constructed on the above data would perhaps be
A, B, C
A, C, B
B, C, A
B, A, C
One of the following is sex-influenced character
Appearance of beard
Baldness in male
Docile behaviour of female
Low BMR in female
A person with the sex chromosomes XXY suffers from :
Down's syndrome
Turner's syndrome
Gynandromorphism
Klinefelter's syndrome
Which one of the following conditions in chromosome number is called monosomy?
2n + 1
2n + 2
2n - 1
2n - 2
C.
2n - 1
Monosomy is the condition of having a diploid chromosome complement in which one chromosome lacks its homologous partner. Eg, Turner's Syndrome.
In Turner's Syndrome, there is presence of 45 pair of chromosomes,ie, (2n - 1) XO. It occurs only in females. These females do not mature sexually and are sterile. They have Short stature and normal intelligence.
Tetrasomy or 2n + 2 is a form of aneuploid with the presence of four copies of chromosomes.
Trisomy or 2n + 1 is a chromosomal disorder characterised by an additional chromosome. Eg, Down's syndrome, Patau's syndrome etc.
Nullisomy or 2n-2 is a genetic condition involving the lack of both the normal chromosomal pair for a species.
Indicate, the inheritance of which of the following is controlled by multiple alleles?
Colourblindness
Sickle cell anaemia
Blood group
Phenylketoneuria
Which of the following conditions is related to haemophilia?
A responsible recessive gene present in the X-chromosome
A responsible dominant gene presentin the X-chromosome
A responsible dominant gene present in the Y-chromosome
A responsible dominant gene present in the autosomal chromosome
The absence of which clotting factor leads to haemophilia-A?
Factor VII
Factor VIII
Factor IX
Factor X
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