12th Standard CBSE - Biology - Principles of Inheritance and Variation

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Question - 1

Heterozygous purple flower is crossed with recessive white flower. The progeny has the ratio :

  • A 75% purple and 25% white
  • B 50% purple and 50% white
  • C All purple
  • D All white

Question - 2

Superiority of hybrid over parents is

  • A Digantism
  • B Lethality
  • C Heterosis
  • D Dwarfism

Question - 3

Two crosses between the same pair of genotype or phenotypes in which the sources of the gametes are reversed in one cross, is known as

  • A Reverse cross
  • B Dihybrid cross
  • C Test cross
  • D Reciprocal cross

Question - 4

Female heterogamy is found in

  • A Birds
  • B Grasshopper
  • C Both a and b
  • D Drosophila

Question - 5

In a plant, red fruit (R) is dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTt genotype is crossed with a plant that is rrtt

  • A 50% will be tall with red fruit
  • B 75% will be tall with red fruit
  • C all the offspring will be tall with red fruit
  • D 25% will be tall with red fruit

Question - 6

A self-fertilizing trihybrid plant forms

  • A 4 different gametes and 16 different zygotes
  • B 8 different gametes and 16 different zygotes
  • C 8 different gametes and 32 different zygotes
  • D 8 different gametes and 64 different zygotes

Question - 7

Male heterogamy is found in

  • A Drosophila
  • B Humans
  • C Grasshopper
  • D All of these

Question - 8

A male human is heterozygous for autosomal genes A and B and is hemizygous for haemophilic gene h. What proportion of his sperms will be abh?

  • A \(\frac{1}{32}\)
  • B \(\frac{1}{16}\)
  • C \(\frac{1}{4}\)
  • D \(\frac{1}{8}\)

Question - 9

The recessive genes located on X-chromosome in humans are always

  • A sub-lethal
  • B expressed in males
  • C expressed in females
  • D lethal

Question - 10

By which process there is a gain o segment of DNA which results in alteration in chromosome?

  • A Insertion
  • B Duplication
  • C Both a and b
  • D Deletion