CBSE Class 12th board Biology Exam previous papers

[Harsh Pandit]

I am searching here question paper for CBSE board of education class 12th biology subject examination ?

Here I am giving you question paper for CBSE board of education class 12th biology subject examination in a PDF file attached with it .

SECTION - A
1. Cite an example of an inverted ecological pyramid. What kind of pyramid of energy would it have? 1
2. When is the structure and composition of a community expected to remain unchanged? 1
3. At what stage of life is oogenesis initiated in a human female? When does the oocyte complete oogenesis? 1
4. After a successful in-vitro fertilisation, the fertilised egg begins to divide. Where is this egg transferred before it
reaches the 8-cell stage and what is this technique named? 1
5. AaBb was crossed with aabb. What would be the phenotypic ratio of the progeny? Mention the term to denote
this kind of cross. 1
6. In F.Griffith’s experiment, how did the nonvirulent strain of Streptococcus Pneumoniae become virulent?
7. State the use of :
(i) Trichoderma with respect to organ transplant, and
(ii) Nucleopolyhedrovirus with respect to pest management 1
8. Bacteria that convert milk into curd play two other beneficial roles. What are they?

SECTION B
9. Given below is a graph depicting organismic response to changing external conditions. According to their response
the organisms are grouped into two types. Name the type which will show (i) pattern A and
(ii) pattern B. 2
(34)
10. Given below is an incomplete flow chart showing influence of hormones on gametogenesis in males. Observe the
flow chart carefully and fill in the blanks A, B, C, and D, 2
2
11. Read the sequence of the nucleotides in the given segment of mRNA and the respective amino acid sequence in
the polypeptide chain.
Polypeptide : met-phe-met-proline-valine-serine
(i) Provide the triplet of bases (codon) for (a) valine (b) proline
(ii) Write the nucleotide sequence of the DNA strand from which this mRNA was transcribed 2
(iii) What does the last codon of this RNA stand for?


CBSE Class 12th board Biology Exam papers








CBSE Class 12th board Biology Exam papers