CBSE Sample Papers for Class 10 Science SA2 with Solutions paper 1
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13. How did Chipko Andolan ultimately benefit the local population? Give three benefits
a) The local benefitted from forest produces
b) The wildlife and nature were conserved
c) The quality of air and soil was preserved
14. Assume brown eye color is recessive to black eye color. If a brown eyed man A has a blue
eyed mother then find
a) What are the possible genotypes of his father?
BB â€“as black eye is dominant.
b) What is the genotype of the man A and his mother?
Genotype of man A is Bb and he will be carrier of recessive gene.
Genotype of mother is bb as brown eye is recessive.
15. What is speciation? What factors could lead to speciation? How is it useful?
The process of formation of new species is called speciation. The factors that led to speciation
ïƒ˜ Geographical isolation
ïƒ˜ Action of environmental factors on the isolated population
ïƒ˜ Reproduction isolation for a long time
ïƒ˜ Genetic drift and natural selection
It aids evolution of new species.
16. Who explained the mechanism of origin of new species for the first time? How does new
species arise according to his theory? What was his second observation?
New species arise by the slow accumulation of advantageous variations over a period of time.
His second observation says that over population results in competition for food and
shelter, ultimately leading to a str uggle for existence among the me mbers of a species.
17. Answer the following
a) Why are the off springs of asexual reproduction called clones?
The off springs of asexual reproduction are called clones as they are genetically similar to
b) Explain spore formation.
Spore Formation â€“ Spores are asexual reproductive bodies enclosed in a thick- walled
structure called sporangium, under favourable conditions spores are released by breaking
sporangium. The spores germinate and develop into new individuals.
c) Name an organism that reproduces by this method
18. Answer the following:
a) Why is variation possible in progeny of sexually reproductive individuals?
Sexual reproduction results in new combinations of genes that are brought together during
gamete formation. This reshuffling of genes in the gametes increases the chances of