Sutton combined Cytological observation on meiotic cell division and Mendel's concept on inheritance
to propose. 

1. Laws of inheritance

2. Chromosomal theory of inheritance

3. Law of segregation

4. Law of sex determination

When the two genes in a dihybrid cross are situated on the same chromosome:
1. The proportion of parental gene combinations was much higher than the non-parental type.
2. The proportion of parental gene combinations was much lesser than the non-parental type.
3. The proportion of parental gene combinations was equal to the non-parental type.
4. Only recombinants are formed.

The two alleles of a gene pair are located on:

1. Homologous sites on homologous chromosomes

2. Heterologous sites on homologous chromosomes

3. Homologous sites on heterologous chromosomes

4. Heterologous sites on heretologous chromosomes

The figure below shows the chromosome segregation during germ cells formation with four stages labelled as (A), (B), (C) and (D). Select the right option giving all the four stages correctly identified

1.  (A) Interphase            (B) Metaphase-l
     (C) Telophase-l           (D) Anaphase-ll

2.  (A) ${\mathrm{G}}_1$                        (B) ${\mathrm{G}}_2$
     (C) Anaphase-l            (D) Anaphase-ll

3.  (A) ${\mathrm{G}}_1$                        (B) ${\mathrm{G}}_2$
     (C) Metaphase-l           (D) Anaphase-l

4.  (A) ${\mathrm{G}}_1$                         (B) ${\mathrm{G}}_2$
    (C) Anaphase-l              (D) Metaphase-ll

Which of the following is a non-parental type of progeny obtained by Morgan while carrying out a dihybrid cross?

1.  

2.  

3.  

4.  

When Morgan hybridised yellow-bodied, white-eyed females to brown-bodied, red-eyed males and intercrossed their F₁ progeny, the F₂ ratio deviated very significantly from the 9:3:3:1 ratio. this can be attributed to the fact that:

(1) The genes are located on X and Y chromosomes

(2) Fruit fly has abnormal chromosomes

(3) The genes are located on the X chromosome

(4) The genes exhibit incomplete dominance

Which one of the following statement is incorrect?