If 'A' represents the dominant gene and 'a' represents its recessive allele, which of the following would be the most likely result in the first generation offspring when Aa is crossed with aa ?

1. All will exhibit dominant phenotype.

2. All will exhibit recessive phenotype. 

3. Dominant and recessive phenotypes will be 50% each.

4. Dominant phenotype will be 75%.

In a pea plants, green pod colour is dominant over yellow pods. 1000 seeds taken from a pea plant on germination produces 760 green pod and 240 yellow pod plants. The parental genotype and phenotype of the seed plant are 

(1) Heterozygous and yellow

(2) heterozygous and green

(3) homozygous and yellow

(4) homozygous and green

A colourblind man marry with a daughter of colourblind father, the generation will be 

(1) there will be no daughter colourblind

(2) all sons will be colourblind

(3) all daughter will be colourblind

(4) half sons will be colourblind

In a plant, red fruit (R) 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. Then

(1) 25% will be tall with red fruit

(2) 50% will be tall with red fruit

(3) 75% will be tall with red fruit

(4) All of the offspring will be tall with red fruits 

A man whose father is a colourblind, marry a woman, who is a daughter of colourblind mother. The offspring of this couple will be

(1) all daugher and sons are colourblind

(2) 50% colourblind and 50% normal son

(3) carrier normal daugher and colourblind sons

(4) colourblind sons and normal daughter

A pea plant parent having violet-coloured flowers with unknown genotype was crossed with a plant having white-coloured flowers. In the progeny, 50% were white. The genotypic constitution of the parent having violet-coloured flowers was

1. homozygous

2. merozygous

3. heterozygous

4. hemizygous

The number of linkage group(s) present in Escherichia coli is 

(1) One

(2) two

(3) four

(4) seven

In two pea plants having red (dominant) coloured flowers with unknown genotypes are crossed, 75% of the flowers are red and 25% are white. The genotypic constitution of the parents having red coloured flowers will be 

(1) both homozygous

(2) one homozygous and other heterozygous

(3) both heterozygous

(4) both hemizygous

Genotypic and phenotypic ratios 1 : 2 : 1 in the offsprings explain the principle of 

(1) dominance

(2) blending inheritance

(3) recessiveness 

(4) All of the above

Sickle cell anaemia is example of 

(1) sex-linked inheritance

(2) deficiency disease

(3) autosomal heritable disease

(4) infectious disease