Subject

Biology

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
Advertisement

 Multiple Choice QuestionsShort Answer Type

11. List any four techniques where the principle of ex-situ conservation of biodiversity has been employed.
1239 Views

Advertisement

12.

State what is apomixis. Comment on its significance. How can it be commercially used?


Apomixis is a form of asexual reproduction in which seeds are formed without fertilisation. It is a form of asexual reproduction that mimics sexual reproduction.

Significance:
Apomixis allows certain species of plants belonging to Asteraceae, and grasses to produce seeds which do not produce seeds by the process of fertilisation.

Commercial applications of apomixis:
1. Hybrid varieties of seeds can be produced in lesser time, which provide higher and better yield.
2. It prevents the loss of specific characteristics in the hybrid plants.
3. Apomixis is a cost-effective method of producing seeds.
1908 Views

Advertisement
13.

During a monohybrid cross involving a tall pea plant with a dwarf pea plant, the offspring populations were tall and dwarf in equal ratio. Work out a cross to show how is it possible.

770 Views

14. Explain the significance of satellite DNA in DNA fingerprinting technique.
1596 Views

Advertisement
15.

What does the following equation represent? Explain
p2 + 2 pq + q2 = 1

781 Views

16.

A heavily bleeding and bruised road accident victim was brought to a nursing home. The doctor immediately gave him an injection to protect him against a deadly disease.

(a) Write what did the doctor inject into the patient's body.
(b) How do you think this injection would protect the patient against the disease?
(c) Name the disease against which this injection was given and the kind of immunity it provides.

1098 Views

17.

Enumerate any six essentials of good, effective Dairy Farm Management Practices.

791 Views

18. State the medicinal value and the bioactive molecules produced by Streptococcus, Monascus and Trichoderma.
960 Views

Advertisement
19.

What are methanogens ? How do they help to generate biogas?

2204 Views

20.

Rearrange the following in the current sequences to accomplish an important biotechnological reaction :

(a) In vitro synthesis of region of DNA of interest
(b) Chemically synthesized oligonucleotides
(c) Enzyme DNA-polymerase
(d) Complementary region of DNA
(e) Genomic DNA template
(f) Nucleotides provided
(g) Primers
(h) Thermostable DNA-polymerase (from Thermus aquaticus)
(i) Denaturation of ds-DNA

731 Views

Advertisement