12th class (Fsc) Biology unit 8 MCQs
26. In cats the dominant allele W not only makes for pure white but also causes:
a. Deafness
b. Black spots
c. Blindness
d. Brown spots
27. How many gene pairs contribute to the wheat grain color?
a. Three
b. One
c. Four
d. Two
28. Human skin colour is a quantitative trait which is controlled by pairs of genes:
a. 3-6
b. 5-8
c. 4-7
d. 4-8
29. The gene pairs which contribute to wheat grain colour are:
a. Three
b. One
c. Four
d. Two
30. Human skin colour is controlled by gene pairs:
a. Four to six
b. Two to four
c. Six to ten
d. Three to six
31. Which phenomenonan reduces the chances of genetic recombination and variations among offspring?
a. Independent assortment
b. Linkage
c. Dominance
d. Crossing over
32. A gamete without any sex chromosome is called:
a. Isogamete
b. Homogamete
c. Nullogamete
d. Heterogamete
33. The gene that triggers development process towards maleness is:
a. MODY
b. TFM
c. BOB
d. SRY
34. Who for the first time found white eye mutant in drosophila?
a. Correns
b. Morgan
c. De varies
d. Bridges
35. Which of the following traits is transmitted directly from an affected father to only his sons?
a. Y-linked
b. Autosomal
c. X and Y linked
d. X-linked
36. Which of the following trait is not sex-kinked recessive
a. Hypophosphatemic ricket
b. Haemophilia
c. Tfm syndrome
d. Color blindness
37. Which of these traits zigzags from maternal grandfather through a carrier daughter to a grandson?
a. Y linked
b. Autosomal
c. X and y linked
d. x-linked
38. When a haemophilic carrier woman marries a normal man, who among her offspring may be affected
a. Half of her daughters
b. All her children
c. Half of her sons
d. All her daughters
39. What is the risk of color blind child in a family when mother is color blind and father is normal
a. 50%
b. 100%
c. 25%
d. 75%
40. What is the risk of a color blind child in a family when father is color blind but mother is normal?
a. 50%
b. Zero%
c. 100%
d. 25%
41. Haemophila C:
a. Affects women more than man
b. Affects both sexes equally
c. Is non allelic recessive sex linked
d. Affects men more than women
42. Blue cone monochromacy is an X-linked trait in which:
a. Red cone cells are absent
b. Green cone cells are absent
c. Both A & B
d. Blue cone cells are absent
43. The gene for blue opsin is present on autosome:
a. 19
b. 07
c. 21
d. 11
44. Hemophilia is:
a. Sex influenced trait
b. X-linked dominant trait
c. Sex limited trait
d. X-linked recessive trait
45. Green colour blindness is called:
a. Tritanopia
b. Deuteranopia
c. Colour blind
d. Protanopia
46. The true colour blindness is:
a. Trichromacy
b. Monochromacy
c. Tetrachromacy
d. Dichromacy
47. Hypophosphatemic rickets in an X-linked:
a. Codominant trait
b. Dominant trait
c. Over dominant trait
d. Recessive trait
48. Deutranopia is a colour blindness of:
a. Green
b. Red
c. Yellow
d. Blue
49. About 20% suffer from haemophilia B due to disturbance in factor:
a. xi
b. ix
c. xii
d. x
50. Which trait is transmitted directly from an affected father to only his sons?
a. Autosomal
b. X-linked
c. X & Y linked
d. Y-linked
51. The maturity on set diabetes of the young is:
a. A sex linked trait
b. An autosomal dominant trait
c. A sex influenced
d. An autosomal recessive unit
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