ICMR Practice Quiz

Question 1

In pea plants, tallness (T) is dominant over dwarfness (t). When two heterozygous tall plants are crossed, what proportion of the offspring is expected to be dwarf?

Accepted Answer

1/4

Question 2

A woman with blood group A whose father had blood group O marries a man with blood group B whose mother had blood group O. Which blood group cannot appear among their children?

Accepted Answer

None; all four ABO groups are possible

Question 3

In a pedigree, an affected father transmits a trait to all his daughters but to none of his sons. This pattern most strongly suggests:

Accepted Answer

X-linked dominant inheritance

Question 4

A recessive lethal allele l causes death in homozygous condition (ll), while heterozygotes are viable. If two heterozygotes are crossed (Ll × Ll), what is the expected ratio among living offspring?

Accepted Answer

2:1

Question 5

In snapdragon, crossing red-flowered plants with white-flowered plants produces pink-flowered offspring. When pink plants are selfed, the phenotypic ratio is 1 red : 2 pink : 1 white. This pattern is called:

Accepted Answer

Incomplete dominance

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