(Download) CBSE Class-12 Sample Paper 2020-21:Biology
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(Download) CBSE Class-12 Sample Paper 2020-21 :Biology
Sample Question Paper 2020-21
Class XII Maximum Marks: 70
Biology (044) Theory
Time: 3 Hours
(i) All questions are compulsory.
(ii) The question paper has four sections: Section A, Section B, Section C and Section D. There are 33 questions in the question paper.
(iii) Section–A has 14 questions of 1 mark each and 02 case-based questions. Section–B has 9 questions of 2 marks each. Section–C has 5 questions of 3 marks each and Section–D has 3 questions of 5 marks each.
(iv) There is no overall choice. However, internal choices have been provided in some
questions. A student has to attempt only one of the alternatives in such questions. (v) Wherever necessary, neat and properly labeled diagrams should be drawn.
SECTION A Questions Marks 1. Why does endosperm development precede embryo development? 1
2. How many meiotic divisions are required to produce 76 seeds in a Guava fruit? 1
3. How does pollination take place in water hyacinth and water lily? 1
4. Name the glands that contribute to human seminal plasma. 1
5. A snapdragon plant with violet flowers was crossed with another such plant with white flowers. The F1 progeny obtained had pink flowers. Explain, in brief, the inheritance pattern seen in offsprings of F1 generation? 1
6. Differentiate between aneuploidy and polyploidy. 1
7. Predict the effect if, the codon UAU coding for an amino acid at the 25th position of a polypeptide of 50 amino acids, is mutated to UAA. 1
8. Differentiate between pro-insulin and mature insulin. 1
9. Name the commonly used vector for cloning genes into higher organisms. 1
10. Which of the three forests- Temperate, Mangroves and Tropical Evergreen is more vulnerable to invasion by outside animals and plants? 1