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.

How are productivity, gross productivity, net primary productivity and secondary productivity interrelated?

1462 Views

Advertisement

12.

Double fertilization is reported in plants of both, castor and groundnut. However, the mature seeds of groundnut are non-albuminous and castor are albuminous. Explain the Post fertilization events that are responsible for it.


Double fertilization occurs in plants of both castor and groundnut but the mature seeds of groundnut are non-albuminous and castor are albuminous. The post fertilization events that are responsible for it are:

The primary endosperm nucleus divides repeatedly to give rise to a free nuclei and the stage of endosperm development is called free nuclear endosperm. The cell wall forms after giving rise to a cellular endosperm.

If the endosperm is fully consumed by the growing embryo then non-albuminous seeds are formed as in groundnut. If the endosperm is retained then it forms albuminous seeds as is the case with castor plant.

973 Views

Advertisement
13.

Describe the process of Parturition in humans.

2263 Views

14.

A teacher wants his/her students to find the genotype of pea plants bearing purple coloured flowers in their school garden. Name and explain the cross that will make it possible.

1059 Views

Advertisement
15.

A DNA segment has a total of 1000 nucleotides, out of which 240 of them are adenine containing nucleotides. How many pyrimidine bases this DNA segment possesses?

531 Views

16.

Draw a diagrammatic sketch of a portion of DNA segment to support your answer.

956 Views

17.

Explain adaptive radiation with the help of a suitable example.

789 Views

18.

A team of students are preparing to participate in the interschool sports meet. During a practice session you find some vials with labels of certain cannabinoids.

(a) Will you report to the authorities? Why?

(b) Name of a plant from which such chemicals are obtained.

(c) Write the effect of these chemicals on human body.

540 Views

Advertisement
19.

Enlist the steps involved in inbreeding of cattle. Suggest two disadvantages of this practice.

611 Views

20.

Choose any three microbes, from the following which are suited for organic farming which is in great demand these days for various reasons. Mention one application of each one chosen.

MycorrhizaMonascusAnabaenaRhizobiumMethanobacteriumTrichoderma.

684 Views

Advertisement