3.
4 marks each.
There is no over all choice in this question paper. Although internal
choices has been provided in some questions.
SECTION-A
1.
Wnte the formula used to calculate the total surface area of a
hemisphencal solid of radius Y.
If each side of a Inanagle is doubled then how many times the area of
triangle increased?
2.
Answers
Answer:
Here is a sample paper of CBSE Class 12 Biology 2019:
Time allowed: 3hrs.
Maximum Marks: 70
General Instructions:
1. There are a total of 26 questions and five sections in the question paper. All questions are compulsory.
2. Section A contains question number 1 to 5, Very Short Answer type questions of one mark each.
3. Section B contains question number 6 to 10, Short Answer type I questions of two marks each.
4. Section C contains question number 11 to 22, Short Answer type II questions of three marks each.
5. Section D contains question number 23, Value Based Question of four marks.
6. Section E contains question number 24 to 26, Long Answer type questions of five marks each.
7. 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.
Section - A
1. A tissue, of a tobacco plant, infected with TMV was used to obtain a new plant. Identify the technique used and reason out the possibility of obtaining a new healthy plant. 1
2. State a method of cellular defense which works in all eukaryotic organisms 1
3. In case of an infertile couple, the male partner can inseminate normally but the mobility of sperms is below 40 percent. Which kind of ART is suitable in this situation to form an embryo in the laboratory conditions, without involving a donor? 1
4. Write the two components of the first artificial recombinant DNA molecule constructed by Cohen and Boyer. 1
5. A cross was carried out between two pea plants showing the contrasting traits of height of the plant. The result of the cross showed 50% of parental characters. Name the type of cross. 1
Section B
6. The alarming population growth is leading to scarcity of basic requirements. Suggest with reasons, any two population control measures other than contraception to address the situation. 2
7. During a cytological study conducted on the chromosomes of the insects, it was observed that only 50% of the sperms had a specific structure after spermatogenesis. Name the structure and write its significance in sex determination of insects. 2
8. medium. 3
13. (a) Name the different gases contained in the flask used as an experimental setup by SL Miller.
(b) On the basis of composition of gases in this experiment, what was the condition in the flask?
(c) Write the conclusion drawn from this experiment. 3
14. When a snapdragon plant bearing pink colour flower was selfed, it was found that, 69 plants were having red coloured flowers. What would be the number of plants bearing pink flower and white flower. Show with the help of Punnett square. Identity the principle of inheritance involved in this experiment. 3
15. Refer to the figure given below and answer the questions that follow:
(a) Explain the process by which Tasmanian wolf evolved.
(b) Name the process that has resulted in evolution of wolf and Tasmanian wolf.
(c) Compare and contrast the two animals shown? 1+1+1
(a) Mention the positive and negative terminals.
(b) What is the charge carried by DNA molecule and how does it help in its separation?
(c) How are the separated DNA fragments finally isolated? 1+1+1
OR
CryI Abis introduced in a plant to prevent infestation by corn borer.
(a) What is the resultant plant referred as?
(b) Summarize the action of the gene introduced ½ +2½
Section D
23. A son persuades his father to replace his old mobile phone with the latest model launched in the market. He also shares the latest features it has and explains how it can be of a help to him in the modern technological world. Father is reluctant in buying a new one and tries to explain about its envir