Question

1. The two types of chromosomes are:

1. Autosomes & allosomes
2. Sex chromosomes & allosomes
3. Sex chromosomes & autosomes
4. X & Y chromosomes

2. In an autosomal inheritance where dominant gene is expressed, all offspring will show dominant homozygous if:

1. Trait is sex-linked
2. Both parents are dominant homozygous
3. Both parents are dominant heterozygous
4. One of the parent is dominant heterozygous

3. In a sex-linked hemophilia disease due to a recessive gene, a mating of homozygous female non-hemophilia with hemophilia male will result in:

1. 100% females with hemophilia
2. 100% males will not be hemophilia
3. 50% males will be hemophilia
4. None of offspring will be hemophilia

4. An individual with same gene in an allele is said to be:

1. Heterozygous
2. Homozygous
3. Haploid
4. Hemizygous

5. The appearance resulting from a given gene combination(allele) is referred to as the:

1. Genotype
2. stereotype
3. phenotype
4. alleleotype

Answer 1

1. The two types of chromosomes are autosomes and allosomes.

Allosomes are also called sex chromosomes.  

so , correct answers are : option (a) and option (c).

2.  According to option (b) ,

Both parents are dominant homozygous - DD × DD, the 4 offsprings will be - DD , DD , DD , DD ( 4 dominant homozygous)

According to option (c) ,

Both parents are dominant heterozygous - Dd × Dd , the 4 offsprings will be - DD , Dd , Dd , dd ( 1 dominant homozygous , 2 dominant heterozygous , 1 recessive homozygous).

Options (a) and (d) will not give all dominant homozygous offsprings.

so , correct answer : option (b)

3.  Affected father - X(h)Y

Non hemophilia mother - XX

The offsprings - X(h)X , X(h)X , XY , XY

- 0% sons affeced , 100 % daughters carriers

so correct answer : option (a)

4.. An individual with same gene in an allele is said to be homozygous for that gene.

so , correct answer : option (b)

5. The appearance resulting from a given gene combination is called phenotype.

so, correct answer : option (c)