Explain the law of independent assortment with a dihybrid cross.

In four o’clock plants, red colour (R) is incompletely dominant over white (r), thus the heterozygous has pink colour. What will be the offspring in a cross between red flower and a pink flower plant?

A man with blood group A married a woman with B group. They have a son with AB blood group and a daughter with blood group O. Work out the cross and show the possibility of such inheritance.

A homozygous tall pea plant with green seeds is crossed with a dwarf pea plant with yellow seeds.

(i) What would be the phenotype and genotype of F₁.

(ii) Work out the phenotypic ratio of F₂ generation with the help of a Punnet square.

Haemophilia is a sex linked recessive disorder of humans. The pedigree chart given below show the inheritance of haemophilia in one family. Study the pattern of inheritance and answer the questions given.

(a) Give all the possible genotypes of the members 4, 5 and 6 in the pedigree chart.

(b) A blood test shows that the individual 14 is a carrier of haemophilia. The member numbered 15 has recently married the member numbered 14. 

What is the probability that their first child will be a haemophilic male?

77. The number of  characters of pea studied by Mendel are ?

• Seven
• Six
• Five
• Four

• Round seed shape
• Axial flower position
• Green seed colour
• Green pod colour.

• induce cell division
• do not show a chromosome map
• show recombination during meiosis
• do not show independent assortment.

• different forms of a gene
• same loci on homologous chromosomes
• contrasting traits.
• All the above.