Morgan worked with the tiny fruit flies - Drosophila melanogaster, which were suitable for genetical studies, as

a.  They could be grown on simple medium

b.  They complete their life cycle in about two weeks

c.  Single mating could produce a large number of progeny flies

d.  No clear cut sexual dimorphism is found 

1.  Only d is incorrect

2.  Both a and d are incorrect

3.  Only b is correct

4.  Both c and d are incorrect 

Match the following

   Column-l                       Column-ll

a.  Haemophilia               i.  Rudimentary ovaries

b.  Sickle cell anaemia     ii.  X-linked recessive

c.  Turner's syndrome      iii.  Gynaecosmastia

d.  Klinefelter's                iv.  Autosomal recessive 
     syndrom

a.  a(ii), b(iv), c(i), d(iii)

b.  a(ii), b(iv), c(iii), d(i)

c.  a(iv), b(ii), c(i), d(iii)

d.  a(iv), b(i), c(ii), d(iii) 

Who noticed that the behaviour of chromosomes is parallel to the behaviour of genes?

1.  Temin and Baltimore

2.  Correns and Tschermak

3.  Beadle and Tatum

4.  Sutton and Boveri 

Experiment verification of the chromosomal theory of inheritance was given by

1.  Sutton and Boveri 

2.  Thomas Hunt Morgan

3.  de Vries

4.  Mendal 

In human ABO group system ________ different alleles allow the possibility of _______ different types of genotypes in population.

1.  3, 4

2.  2, 4

3.  3, 6

4.  6, 3 

The phenotype of an individual may be affected if the modified allele produces

A.  The normal/less efficient enzyme

B.  No enzyme at all

C.  A non-functional enzyme

1.  Only A is correct 

2.  Only C & A are correct

3.  Only B is correct

4.  B & C are correct 

Ability of a gene to have multiple phenotypic effects is known as

1.  Co-dominance 

2.  Pleiotropy

3.  Multiple allelism

4.  Incomplete dominance 

Morgan and his group observed when the two genes in a dihybrid cross were situated on the same chromosome, the proportion of parental gene combinations were much higher than the non-parental type, this is due to

1.  Independent assortment 

2.  Linkage

3.  Crossing over

4.  Competence 

What is probability of homozygous individuals for both characters in ${\mathrm{F}}_2$ generation of a dihybrid cross?

1.  1/2

2.  3/4

3.  1/3

4.  1/4 

Choose correct option with respect to given figure for determination of sex by chromosomal differences.

1.  b after spermatogenesis forms only one type of gametes

2.  b & c represents same sex

3.  a, d are heterogametic

4.  Sex determination in d is similar to grasshopper