Board Paper of Class 12-Science 2016 Biology Delhi(SET 1) - Solutions
(i) There are a total of 26 questions and five sections in the question paper, All questions are compulsory.
(ii) Section A contains question number 1 to 5, Very Short Answer type questions of one mark each.
(iii) Section B contains question number 6 to 10, Short Answer type I questions of two marks each.
(iv) Section C contains question number 11 to 22, Short Answer type II questions of three marks each.
(v) Section D contains question number 23, Value Based Question of four marks.
(vi) Section E contains question number 24 to 26, Long Answer type questions of five marks each.
(vii) There is no overall choice in the question paper, however, an internal choice is provided in one question of two marks, one question of three marks and all three questions of five marks. An examinee is to attempt any one of the questions out of the two given in the question paper with the same question number.
- Question 1
According to de-Vries what is saltation? VIEW SOLUTION
- Question 2
Excessive nutrients in a fresh water body cause fish mortality. Give two reasons. VIEW SOLUTION
- Question 3
Suggest the breeding method most suitable for animals that are below average in milk productivity. VIEW SOLUTION
- Question 4
State a difference between a gene and an allele. VIEW SOLUTION
- Question 5
Suggest a technique to a researcher who needs to separate fragments of DNA. VIEW SOLUTION
- Question 6
Explain the significance of meiocytes in a diploid organism. VIEW SOLUTION
- Question 7
Mention the kind of biodiversity of more than a thousand varieties of mangoes in India represent. How is it possible? VIEW SOLUTION
- Question 8
List the events that reduce the Biological Oxygen Demand (BOD) of a primary effluent during sewage treatment. VIEW SOLUTION
- Question 9
Discuss the role the enzyme DNA ligase plays during DNA replication. VIEW SOLUTION
- Question 10
Name the causative organism of the disease amoebiasis. List three symptoms of the disease.
Identify 'A', 'B', 'C' and 'D' in the given table.
Crop Variety Resistance to disease Himgiri Leaf rust Cauliflower Pusa Shubhra Brassica Pusa Swarnim Cowpea Bacterial blight
- Question 11
Why is breast-feeding recommended during the initial period of an infant's growth? Give reasons. VIEW SOLUTION
- Question 12
Give an example of an autosomal recessive trait in humans. Explain its pattern of inheritance with the help of a cross. VIEW SOLUTION
- Question 13
Describe the experiment that helped Louis Pasteur to dismiss the theory of spontaneous generation of life. VIEW SOLUTION
- Question 14
Plant breeding technique has helped sugar industry in North India. Explain how. VIEW SOLUTION
- Question 15
Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro. VIEW SOLUTION
- Question 16
What is a GMO? List any five possible advantages of a GMO to a farmer. VIEW SOLUTION
- Question 17
During a school trip to 'Rohtang Pass', one of your classmate suddenly developed 'altitude sickness'. But, she recovered after sometime.
(a) Mention one symptom to diagnose the sickness.
(b) What caused the sickness?
(c) How could she recover by herself after sometime? VIEW SOLUTION
- Question 18
How has RNAi technique helped to prevent the infestation of roots in tobacco plants by a nematode Meloidegyne incognitia? VIEW SOLUTION
- Question 19
"In a food-chain, a trophic level represents a functional level, not a species." Explain.
(a) Name any two places where it is essential to install electrostatic precipitators. Why it is required to do so?
(b) Mention one limitation of the electrostatic precipitator. VIEW SOLUTION
- Question 20
Prior to a sports event blood & urine samples of sports-persons are collected for drug tests.
(a) Why is there a need to conduct such tests?
(b) Name the drugs the authorities usually look for.
(c) Write the generic names of two plants from which these drugs are obtained. VIEW SOLUTION
- Question 21
Describe the experiment that helped demonstrate the semi-conservative mode of DNA replication. VIEW SOLUTION
- Question 22
Given below is a list of six micro-organisms. State their usefulness to humans.
(b) Saccharomyces cerevisiae
(c) Monascus purpureus
(d) Trichoderma polysporum
(e) Penicillium notatum
(f) Propionibacterium sharmanii VIEW SOLUTION
- Question 23
Reproductive and Child Healthcare (RCH) programmes are currently in operation. One of the major tasks of these programmes is to create awareness amongst people about the wide range of reproduction related aspects. As this is important and essential for building a reproductively healthy society.VIEW SOLUTION
(a) "Providing sex education in schools in one of the ways to meet this goal." Give four points in support of your opinion regarding this statement.
(b) List any two 'indicators' that indicate a reproductively healthy society.
- Question 24
(a) Explain the post-pollination events leading to seed production in angiosperms.
(b) List the different types of pollination depending upon the source of pollen gain.
Or(a) Briefly explain the events of fertilisation and implantation in an adult human female.VIEW SOLUTION
(b) Comment on the role of placenta as an endocrine gland.
- Question 25
(a) How are the following formed and involved in DNA packaging in a nucleus of a cell?(i) Histone octomer
(b) Differentiate between Euchromatin and Heterochromatin. VIEW SOLUTION
- Question 26
(a) Why should we conserve biodiversity ? How can we do it?
(b) Explain the importance of biodiversity hot-spots and sacred groves.
(a) Represent diagrammatically three kinds of age-pyramids for human populations.
(b) How does an age pyramid for human population at given point of time helps the policy-makers in planning for future. VIEW SOLUTION