MEDIUM
12th CBSE
IMPORTANT
Earn 100
A cross between a normal couple resulted in a son who was haemophilic and in normal daughter. In course of time when the daughter was married to a normal man to their surprise, the grandson was also haemophilic.
Write the conclusion about the inheritance pattern of this disease.
Important Questions on Principles of Inheritance and Variations
MEDIUM
12th CBSE
IMPORTANT
Two independent mono-hybrid crosses were carried out involving a tall pea plant and a dwarf pea plant. In the first cross, the offspring population had an equal number of tall and dwarf plants, whereas in the second cross it was same. Work out the crosses and explain giving reasons for the differences in the population.
MEDIUM
12th CBSE
IMPORTANT
The F2 progeny of a monohybrid cross showed phenotypic and genotypic ratio 1:2:1 Mendel’s monohybrid F2 ratio. With the help of a suitable example, explain how it is possible.
HARD
12th CBSE
IMPORTANT
Name the kind of disease/disorders that are likely to occur in human if, mutation in the gene that codes for an enzyme phenylalanine hydrolase occurs.
MEDIUM
12th CBSE
IMPORTANT
Name the kind of disease/disorders that are likely to occur in human if, There is an extra copy of chromosome 21.
HARD
12th CBSE
IMPORTANT
Name the kind of disease/disorders that are likely to occur in human if the karyotype is XXY.
HARD
12th CBSE
IMPORTANT
Give symptoms of any one of the disease/disorders- phenylketonuria, Down’s Syndrome or Klinefelter’s Syndrome.
MEDIUM
12th CBSE
IMPORTANT
What is a test cross? How can it decipher the heterozygosity of a plant?
MEDIUM
12th CBSE
IMPORTANT
A couple with normal vision bears a colour-blind child. Work out a cross to show how it is possible and mention the sex of the affected child.
