Biology Delhi (Set 2)

General Instructions:

Read the following instructions very carefully and strictly follow them:

1. Question paper comprises five sections – A, B, C, D and E.
2. There are 27 questions in the question paper. All questions are compulsory.
3. Section A question number 1 to 5 are multiple choice questions, carrying one mark each.
4. Section B question number 6 to 12 are short answer questions type-I, carrying two marks each.
5. Section C question number 13 to 21 are short answer questions type-II, carrying three marks each.
6. Section D question number 22 to 24 are short answer questions type-III, carrying three marks each.
7. Section E question number 25 to 27 are long answer questions, carrying five marks each.
8. Answer should be brief and to the point also the above word limit be adhered to as far as possible.

1. There is no overall choice in the question paper. However, an internal choice has

been provided in two questions of 1 mark, one question of 2 marks, two questions of 3 marks and three questions of 5 marks questions. Only one of the choices in such questions have to be attempted.

1. The diagram drawn should be neat proportionate and properly labelled, wherever necessary.
2. In addition to this, separate instructions are given with each section and question, wherever necessary.

Question 1

In a bacterium when RNA-polymerase binds to the promoter on a transcription unit during transcription, it

1. terminates the process
2. helps remove introns
3. initiates the process
4. inactivates the exons

Solution:

RNA polymerase is the key enzyme for the process of transcription. This enzyme

recognizes the promoter region and initiates the transcription process. This leads to the

formation of RNA (or mRNA) from the template DNA.

Hence, the correct answer is option C.

Question 2

The first cellular form of life evolved

1. in air
2. on land
3. in water environment
4. in deep soil

Solution:

The first cellular forms of life evolved in water.

Hence, the correct answer is option C.

Question 3

Mating of a superior male of a breed of a cattle to a superior female of another breed is called

1. in breeding
2. out crossing
3. out breeding
4. cross breeding

OR Large-holes in 'Swiss-Cheese' are due to

1. Propionibacterium sharmanii
2. Saccharomyces cerevisae
3. Penicillium chrysogenum
4. Acetobacter aceti

Solution:

Mating of superior male of one breed and superior female of another breed to obtain the desirable qualities of two breeds can be combined by the process of cross breeding. e.g., Hisardale is a new breed of sheep developed in Punjab by crossing Bikaneri ewes and Marino rams.

Hence, the correct answer is option D.

OR

The large holes in 'Swiss cheese' are due to the production of a large amount of CO₂ by a bacterium called Propionibacterium sharmanii.

Hence, the correct answer is option A.