Genetic Basis of Inheritance – Competative exam questions Part – 1

1. A cross between homozygous recessive and heterozygous plant is
a)Monohybrid cross
b)Dihybrid cross
c)Test cross
d)Back cross

2. In Red-white flowered cross of Mirabilis jalapa, F2 generation has red, pink and white flowered plants in the ration of
a)1:2:1
b)1:0:1
c)2:1:1
d)1:1:2

3. A blue fowl obtained from mating between black and white fowls, is self-crossed. The F2 ratio is
a)1 black:2 white: 1 blue
b)2 black: 1 white: 1 blue
c)1 black: 2 blue :1white
d)none of these

4. Epistasis in which dihybrid ratio of 9:3:3:1 between Aa Bb ×AaBbis modified is
a)dominance of one allele on another allele at the same locus
b)dominance of one allele on another allele at both its loci
c)interaction of two alleles at different loci
d)interaction between two alleles at same locus

5. Which amino acid is substituted in sickle cell anaemia
a)Glutamic acid by valine in α−chain
b)Glutamic acid by valine in β−chain
c)Valine by glutamic acid in β−chain
d)Valine by glutamic acid in α−chain

6. Mendel found certain traits not ti assort independently. It is due to
a)dominance
b)linkage
c)crossing over
d)amitosis

7. If Mendel had studied 7 traits using a plant with 12 chromosomes instead of 14, he would have
a)discovered incomplete dominance
b)not discovered the law of independent assortment
c)discovered sex linkage d)mapped the chromosome

8. Crossing over in diploid organisms is responsible for
a)Dominance of genes
b)Linkage between genes
c)Recombination of linked genes
d)segregation of alleles

9. Huntington’s chorea appears at the age of
a)25-55 years
b)15-25 years
c)50-60 years
d)10-15 years

10. Persons with Klinefelter’s syndrome have chromosomes
a)XX
b)XY
c)XXY
d)XYY

Answer
1C,2A,3C,4B,5B,6B,7B,8C,9A,10C

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