Previous Year Paper year:2019 : ICSE-X-Biology

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ICSE-X-Biology

Previous Year Paper year:2019

with Solutions - page 7

#5-a-ii
Mention two characteristic features each for the two stages.
Ans : To prevent escape of water vapour from the pot.

#5-a-iii
Who proposed the theory of ‘Natural Selection’ ?
Ans :
Intensity of sunlight
Increase in temperature

#5-a-iv
Name the organism used as an example to explain ‘Industrial Melanisum’.
Ans :
Sunken stomata
Thick cuticle

#5-a-v
Give two examples of Vestigial organs in humans.
Ans :

#5-b
Given below are two stages in the evolution of man. study them and answer the questions that follow:
[5]

#5-b-i
Identify Australopithecus and Neanderthal man from the above pictures.
Ans : A - Neanderthal

B - Australopithecus

#5-b-ii
Mention two charcterstic feature each for the two stages.
Ans : A - Height 600 cm, cranial capacity 1450 cm³

B - Height 120 cm, cranial capacity 450 - 600 cm³

#5-b-iii
Who proposed the theory of ‘Natural Selection’?
Ans : Charles Darwin

#5-b-iv
Name the organism used as an example to ‘Industrial Melanisum’.
Ans : peppered moth (Biston bitularia)

#5-b-v
Give two examples of vestigial organs in humans.
Ans : Vermiform Appendix ; Wisdom tooth

#6

#6-a
In Mendel’s experiments, tall pea plants (T) are dominant over dwarf pea plants (t).
[5]

#6-a-i
What is the phenotype and genotype of the F₁generation if a homozygus tall plant is crossed with a homozygus dwarf plant?
Ans : Phenotype of F₁generation is all are tall plants.

Genotype of F₁generation is all plants are Tf.

#6-a-ii
Draw a Punnett square board to show the gametes and offspring when both the parents the heterozygus for tallness.
Ans : Punett square is as follows :

#6-a-iii
What is the Phenotypic ratio and genotypic ratio of the above cross in (ii)?
Ans : Phenotypic ratio = 3:1

Genotypic ratio = 1:2:1