CBSE: Check CBSE Class 12 Biology Marking Scheme 2021 along with the latest CBSE Class 12 Biology Sample Paper 2021 is available here. Links to download these resources are given at the end of this article. These resources are essential for the preparation of the upcoming CBSE Class 12 Biology Board Exam 2021. With the help of the latest CBSE Sample Paper of Class 12 Biology, students can understand the new pattern of CBSE Class 12 Biology Board Exam 2021. Also, with the help of CBSE Class 12 Biology Marking Scheme 2021, students can easily understand the correct way of writing informative answers.
Also Check: New CBSE Syllabus 2020-21 (Revised & Reduced By 30%) - PDF: 9th, 10th, 11th, 12th!
CBSE Class 12 Biology Marking Scheme 2021:
Q. Why does endosperm development precedes embryo development?
A.
The cells of endosperm are filled with reserve food materials and are used for the nutrition of the developing embryo. [1]
Q. How many meiotic divisions are required to produce 76 seeds in a Guava fruit?
A.
95. [1]
Q. How does pollination take place in water hyacinth and water lily?
A.
In water hyacinth and water lily, the flowers emerge above the level of water and are pollinated by insects or wind as in most of the land plants. [1]
Q. Name the glands that contribute to human seminal plasma.
A.
Prostate, Seminal vesicle and Bulbourethral gland.
(any two)
Q. 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?
A.
The inheritance is incomplete dominance. In this, a new intermediate phenotype between the two original phenotypes is obtained. One allele for a specific trait is not completely expressed over the other allele for the same trait. [1]
Q. Differentiate between aneuploidy and polyploidy
A.
Aneuploidy is chromosomal abnormality in which one or more chromosomes are gained or lost. Polyploidy is when an entire extra set of chromosomes is added. (It may be triploid or tetraploid.) [1]
Q. 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
A.
A polypeptide of 24 amino acids will be formed as UAA is a stop codon which will prevent further translation. [1]
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For the rest of the questions and answers, download the CBSE Class 12 Biology Marking Scheme 2021 & the latest CBSE Class 12 Biology Sample Paper 2021 .
- Download CBSE Class 12 Biology Marking Scheme 2021
- Download CBSE Class 12 Biology Sample Paper 2021
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