Class 12 · Biology · CBSE Board · 2020

Class 12 Biology 2020 Board Exam

152 questions from the 2020 Class 12 exam, combined from all 6 question paper sets (Set 1–6) with duplicates removed.

152questions
6exam sets
13chapters covered
1 / 2 / 3 / 5mark values
Note: The 2020 board exams were held in early 2020, just before the nationwide COVID-19 lockdown.

Questions from the 2020 exam first 10 of 152 — free

Q1MCQ20201 mark
  1. Cleistogamous flowers are self-pollinated because
    [Max Marks: 1 | Sets: 57/1/2, 57/2/1]
(A)Penicillium
(B)Hydra
(C)Sponge
(D)Chlamydomonas
Q220201 mark
  1. Name the type of cross that would help to find the genotype of a pea plant bearing violet flowers.
    [Max Marks: 1 | Set: 57/1/1]
Q3MCQ20201 mark
  1. Meselson and Stahl carried out centrifugation in CsCl2 density gradient to separate :
    [Max Marks: 1 | Set: 57/1/1]
(A)DNA from RNA
(B)DNA from protein
(C)The normal DNA from 15N-DNA
(D)DNA from tRNA
Q420201 mark
  1. How do cytokine barriers provide innate immunity in humans ?
    [Max Marks: 1 | Set: 57/1/3]
Q5MCQ20201 mark
  1. ' 'Cry' protein' coded by gene Cry IAb controls
    [Max Marks: 1 | Set: 57/1/2]
(A)Cotton bollworm
(B)Corn borer
(C)Tobacco budworm
(D)Mosquito
Q620201 mark
  1. Mention the chemical change that proinsulin undergoes, to be able to act as mature insulin.
    [Max Marks: 1 | Set: 57/2/1]
Q7MCQ20201 mark
  1. Which one of the following is not the product of transgenic experiments ?
    [Max Marks: 1 | Set: 57/2/3]
(A)Pest-resistant crop variety
(B)High nutritional value in grains
(C)Production of insulin by rDNA technique
(D)Drought-resistant crops
Q8MCQ20201 mark
  1. Meselson and Stahl carried out centrifugation in CsCl2 density gradient to separate :
    [Max Marks: 1 | Set: 57/1/2]
(A)DNA from RNA
(B)DNA from protein
(C)The normal DNA from 15N-DNA
(D)DNA from tRNA
Q9MCQ20201 mark
  1. Micropropagation can be achieved by
    [Max Marks: 1 | Set: 57/1/3]
(A)Lactobacillus and Yeast
(B)Penicillium and Yeast
(C)Microspora and E. coli
(D)Rhizopus and Lactobacillus
Q1020201 mark
  1. State two postulates of Oparin and Haldane with reference to origin of life.
    [Max Marks: 1 | Set: 57/1/1]

Chapters covered in the 2020 exam

About the 2020 Class 12 Biology paper

CBSE conducted the 2020 Class 12 Biology board exam in 6 question paper sets — students in different regions received different sets of the same exam. This page combines every set and removes repeated questions, giving you all 152 unique questions actually asked that year. The 2020 questions drew from 13 chapters of the syllabus.

Other Class 12 Biology papers

Class 12 Biology 2020 Question Paper — PYQs | Padhify