Question

Chromosomal theory of inheritance is a combination of:

• A. knowledge of chromosomal segregation with Mendelian principles
• B. knowledge of dihybrid cross with movement of chromosomes
• C. knowledge of the Law of dominance with chromosomal appearance
• D. knowledge of classical genetics with modern molecular biology

Answer 1

The correct option is A knowledge of chromosomal segregation with Mendelian principles

Chromosomal theory of inheritance was given by Sutton and Boveri.

They noted that behaviour of chromosomes was similar to behaviour of genes (factors).

Both genes and chromosomes occur in pairs, segregate at the time of gamete formation such that each gamete receives one member of each pair and paired condition is restored after fertilisation. With this, they were able to explain Mendel’s laws.

Mendel's law of segregation states that the factors controlling a character segregate at the time of gamete formation. Sutton and Boveri tried to explain this by stating that genes (factors) are located on chromosomes and when the homologous pair of chromosomes separate during gamete formation, the factors carried by those chromosomes also separate.

Hence, they united the knowledge of chromosomal segregation with Mendelian principles and called the theory as chromosomal theory of inheritance.

This theory has nothing to do with comparison of dihybrid cross with chromosomal movement, law of dominance with chromosomal appearance or classical genetics with molecular biology.