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Free Download as PDF of the detailed solutions for class 12 Biology from NCERT or CBSE text book as per exam pattern, to help you in day to day learning. We provide all important questions and answers from chapter Strategies for Environment and Food Production of Biology.
31
In which crops is the method of mass selection applied
[1]
Self-pollinated
[2]
Cross-pollinated
[3]
Both self and cross-pollinated
[4]
Potato and sugarcane
32
A large proportion of cultivated plants are _______.
[1]
Aneuploids
[2]
Allopolyploids
[3]
Autopolyploids
[4]
Haploids
33
Mutations can be induced with
[1]
Infra Red radiations
[2]
Ethylene
[3]
Gamma radiations
[4]
None of these
34
Selection of homozygous plant is
[1]
Mixed selection
[2]
Mass selection
[3]
Pure line selection
[4]
none of these
Answer: Pure line selection
35
Breeding crops with higher levels of minerals, vitamins or higher protein and healthier fats is called
[1]
Micropropagation
[2]
Somatic hybridization
[3]
Biofortification
[4]
Biomagnification
36
In order to obtain disease-free plants through tissue culture techniques, the best method is
[1]
Protoplast culture
[2]
Anther culture
[3]
Embryo rescue
[4]
Meristem culture
37
When two unrelated individuals or lines are crossed, the performance of F1 hybrid is often superior to both its parents. This phenomenon is called
[1]
Metamorphosis
[2]
Heterosis
[3]
Transformation
[4]
none of these
38
The entire collections of plants/seeds having all diverse alleles for all the genes of a crop is called
[1]
Germplasm
[2]
Herbarium
[3]
Genome
[4]
Gene library
39
Which one of the following helps in absorption of phosphorus from soil by plants?
[1]
Anabaena
[2]
Glomus
[3]
Rhizobium
[4]
Frankia
40
The best way to obtain bacteria and viruses free plants through tissue culture
[1]
Seed germination after gamma-irradiation
[2]
Micropropagation
[3]
Shoot apex or meristem culture
[4]
Seed germination under aseptic conditions
Answer: Shoot apex or meristem culture
41
Pure line breeds refer to
[1]
Heterozygosity
[2]
Homozygosity only
[3]
Homozygosity and independent assortment
[4]
Heterozygosity and linkage
Answer: Homozygosity only
42
The dividing and undifferentiated cells are known as
[1]
Embryo
[2]
Proembryo
[3]
Callus
[4]
Primordium
43
The chances of contacting bird flu from a properly cooked (above 100°C) chicken and egg are:
[1]
very high
[2]
high
[3]
high
[4]
none
44
Micro-propagation is:
[1]
propagation of microbes in vitro
[2]
propagation of plants in vitro
[3]
propagation of cells in vitro
[4]
growing plants on smaller scale.
Answer: propagation of plants in vitro
45
More than 70 per cent of livestock population is in:
[1]
Denmark
[2]
India
[3]
China
[4]
India and China.
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