CBSE Marking Scheme for Class 12 Biology board exam 2017 (Delhi Region) is available here. This paper was held on 5 April 2017. Students can download this Marking Scheme in PDF format.
This Marking Scheme is provided with key points. During the evaluation of CBSE Class 12 Biology board exam’s answer booklets, the answers with all key points (as given in marking scheme) were awarded maximum marks.
CBSE Class 12 Biology Marking Scheme also contains key answers (or values point) with mark wise break up, which gives a better idea about the division of marks inside a question. With this Marking Scheme, students can easily understand about the requirement of a perfect answer.
Students can download CBSE Class 12 Biology Marking Scheme 2017 (Delhi Region) in PDF format from the download link given at the end of this article. CBSE Class 12 Biology 2017 board exam question paper (Delhi) is also available for reference.
Some content from the Marking Scheme is given below:
The Marking Scheme and mechanics of marking
1 In the marking scheme the marking points are separated by commas, one oblique line (/) indicates acceptable alternative, two obliques (//) indicate complete acceptable alternative set of marking points.
2. Any words/phrases given within brackets do not have marks.
3. Allow spelling mistakes unless the misspelt word has another biological meaning. Ignore plurals unless otherwise stated in the marking scheme.
4. In any question exclusively on diagram no marks on any description. But in questions on descriptions, same value points may be marked on the diagrams as a subsitute.
5. All awarded marks are to be written in the left hand margin at the end of the question or its part.
6. Place a tick (√) in red directly on the key/operative term or idea provided it is in correct context. Place “Half-tick” ½ wherever there is ½ mark in the marking scheme. (Do not place tick indiscriminately just to show that you have read the answer).
7. If no marks are awarded to any part or question put a cross (×) at incorrect value portion and mark it zero (in words only).
8. Add up ticks or the half ticks for a part of the question, do the calculation if any, and write the part total or the question total in the left hand margin.
9. Add part totals of the question and write the question total at the end. Count all the ticks for the entire question as a recheck and draw a circle around the question total to confirm correct addition.
10. If parts have been attempted at different places do the totalling at the end of the part attempted last.
11. If any extra part is attempted or any question is reattempted, score out the last one and write “extra”.
12. In questions where only a certain number of items are asked evaluate only that many numbers in sequence as is asked ignoring all the extra ones even if otherwise correct.
13. Transcribe the marks on the cover page. Add up question totals. Recheck the script total by adding up circled marks in the script.
14. Points/answer given in brackets in marking scheme are not so important and may be ignored for marking.
SECTION – A
(Q. Nos. 1 - 5 are of one mark each)
Question 1: Our government has intentionally imposed strict conditions for M.T.P. in our country. Justify giving a reason.
Ans. To prevent female foeticide / to maintain sex ratio / to avoid any danger for (young) mother (and foetus) [1 mark]
Question 2: State the fate of a pair of autosomes during gamete formation.
Ans. Segregate / separate [1 mark]
Question 3: What role does an individual organism play as per Darwin’s theory of natural selection?
Ans. Individual with reproductive fitness passes on the useful gene to the next generation [1 mark]
Question 4: Suggest a method to ensure an anamnestic response in humans.
Ans. Vaccination / Immunization (Active / passive) / weakened or inactive microbes or pathogens or proteins or antibodies introduced into the host body [1 mark]
Question 5: What is biopiracy ?
Ans. Use of bioresources by MNC/organizations / individuals, without proper authorization / legal permission / without compensatory payment from the countries and people concerned = ½ + ½ [1 mark]