In a test cross involving F₁ dihybrid flies, more parental-type offspring were produced than the recombinant type offspring. This indicates

(1) chromosomes failed to separate during meiosis 

(2) the two genes are linked and present on the same chromosome

(3) both of the characters are controlled by more than one gene

(4) the two genes are located on two different chromosomes

Match the terms in Column I with their description in Column II and choose the correct option.

Codes : 

Which of the following most appropriately describes haemophilia?

(1) X-linked recessive gene disorder

(2) Choromosomal disorder

(3) dominant gene disorder

(4) Recessive gene disorder

The term "linkage" was coined by :-

1. TH Morgan

2. T Boveri

3. G Mendel

4. W Sulton

In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree

1. Autosomal dominant

2. X-linked recessive

3. Autosomal recessive

4. X-linked dominant

Multiple alleles are present 

1. on different chromosomes

2. at different loci on the same chromosome

3. at the same locus of the chromosome

4. on non-sister chromatids

An abnormal human baby with 'XXX' sex chromosomes was born due to

1. formation of abnormal sperms in the father

2. formation of abnormal ova in the mother

3. fusion of two ova and one sperm

4. fusion of two ova and two sperm

Alleles are

1. different phenotype

2. true breeding homozygotes

3. different molecular forms of a gene

4. heterozygotes

A human female with turner's syndrome

(1) has 45 chromosomes with XO

(2) has one additional X-chromosome

(3) exhibits male characters

(4) is able to produce children with normal husband

Which of the following statements is not true of two genes that show 50% recombination frequency?

(1) the genes may be on different chromosomes 

(2) the genes are tightly linked

(3) the genes show independent assortment

(4) If the genes are present on the same chromosome, they undergo more than one crossovers in every meiosis