Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Mention the evolutionary significance of the Homo habilis

Mention the evolutionary significance of the Homo erectus

How has the development of bioreactor helped in biotechnology?

Name the most commonly used bioreactor and describe its working.

Explain divergent evolution with two examples. 

One of the major contributions of biotechnology is to develop pest-resistant varieties of cotton plants. Explain how it has been made possible.

Name and explain the technique used for separating DNA fragments and making them available for biotechnology experiments.

Answer the following question:
Name the group of bacteria involved in setting milk into curd. Explain the process they carry in doing so. Write another beneficial role of such bacteria.

Answer the following question:
Why does 'Swiss Cheese' develop large holes?

What is the cell that receives a recombinant gene called?

Give a reason why :
Proteases are added during the isolation of DNA for genetic engineering.

Name the microbes that help the production of the following product commercially:
Citric acid

A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the parents?

In a dihybrid cross, if you get 9:3:3:1 ratio it denotes that ______.

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

Two linked genes a and b show 20% recombination. The individuals of a dihybrid cross between ++ /++ × ab/ab shall show gametes ______.

A normal green male maize is crossed with albino female. The progeny is albino because ______.

A dihybrid condition is ______.

Mendel’s last law is ______.

The process of mating between closely related individuals is ______.