Biology, asked by sarkarsubhojyoti345, 7 months ago

1. What is a gene? (1)
2. What is meant by analogous organs? Taking a suitable example, explain how they support the theory of Organic Evolution. (3)
3. The sex of the children is determined by what they inherit from their father and not their mother.” Justify. (3)
4. Distinguish between acquired and inherited traits by giving one example of each. Why are traits acquired during the lifetime of an individual not inherited? (3)
5. Explain the terms: (i) Speciation (ii) Natural selection (2)
6. A blue colour flower plant denoted by BB is cross bred with that of white colour flower plant denoted by bb.
(a) State the colour of flower you would expect in their F1  generation plants.
(b) What must be the percentage of white flower plants in F2  generation if flowers of F1 plants are self-pollinated?
(c) State the expected ratio of the genotypes BB and Bb in the F2 progeny. (5)
7. Define the term ‘evolution’. “Evolution cannot be equated with progress”. Justify this statement. (3)
8. If we cross pure-bred tall (dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea plants of F1 generation. If we now self-cross the pea plant of F2  generation, then we obtain pea plants of F2  generation.
(a) What do the plants of F2 generation look like?
(b) State the ratio of tall plants to dwarf plants in F2 generation.
(c) State the type of plants not found in F2 generation but appeared in F2 generation, mentioning the reason for the same. (5)
9. How are fossils formed? Describe, in brief, two methods of determining the age of fossils. (3)
10. What are homologous organs? Can the wing of a butterfly and the wing of a bat be regarded as homologous? Why? (5)

Answers

Answered by ankushsaini23

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