Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions for Biology

Chromosomal theory of inheritance was given by ______.

Experimental verification of ‘chromosomal theory of inheritance’ was done by ______.

Chromosome maps/genetic maps were first prepared by ______.

How many types of gametes would be produced if the genotype of a parent is AaBB?

Which of the following statements indicates parallelism in genes and chromosomes?

1. They occur in pairs.
2. They segregate during gamete formation.
3. They show linkage.
4. Independent pairs segregate independently.

What would be the genotype of the parents if the offspring have the phenotypes in 1:1 proportion?

A couple has two daughters. What is the probability that the third child will also be a female?

What are minisatellites?

There was a mix-up at the hospital after a fire accident in the nursery division. Which of these children belong to the parents? 

How do genes and chromosomes share similarity from the point of view of genetical studies?

Discuss in detail the contributions of Morgan and Sturvant in the area of genetics.

Name any two sources of e-Wastes and write two difference ways of their disposal.

An electrostatic precipitator in a thermal power plant is not able to generate a high voltage of several thousand. Write the ecological implication because of it.

Distance between the genes and percentage of recombination shows ______.

Occasionally, a single gene may express more than one effect. The phenomenon is called ______.

Discuss why Drosophila has been used extensively for genetical studies.

What is recombination? Discuss the applications of recombination from the point of view of genetic engineering.

Assertion: When white eyed, yellow bodied Drosophila females were hybridized with red eyed, brown-bodied males; and F₁ progeny was intercrossed, F₂ ratio deviated from 9 : 3 : 3 : 1.

Reason: When two genes in a dihybrid are on the same chromosome, the proportion of parental gene combinations is much higher than the non-parental type.

What is the basic principle of vaccination? How do vaccines prevent microbial infections? Name the organism from which hepatitis B vaccine is produced.

What are recombinant DNA vaccines? Give two examples of such vaccines. Discuss their advantages.