The disease colour blindness is a :

1. Recessive X-linked disease
2. Dominant Y-linked disease
3. Recessive Y-linked disease
4. Dominant X-linked disease

The physical expression of a character is called :

1. Genotype
2. Alleles
3. Phenotype
4. Traits

The phenotypic dihybrid ratio of F₂ generation is

1. 9:3:1:1
2. 9:1:3:1
3. 9:1:3:3
4. 9:3:3:1

In the human male, a sperm contains autosomes and :

1. X and Y chromosomes
2. Only X chromosome
3. X or Y chromosome
4. Only Y chromosome