The Origin of Life & Evidences of Evolution

1 Mark Questions

1. Why are analogous structures a result of convergent evolution? [All India 2014]

Ans. When two species have structures that are similar in function but differ in origin and anatomy are called analogous structures. This is because both move from different areas to a habitat where they adapt themselves accordingly, therefore it is called convergent evolution.

2. Name the type of evolution that, has resulted in the development of structures like wings of butterfly and bird. What are such'structures Called? [Delhi 2014 C]

Ans. Convergent evolution has resulted in the development of structures like wings of butterfly and bird and such structures are called analogous organs.

3.State the significance of the study of fossils in evolution. [Delhi 2012]

Ans. Fossils help us to know the morphological details of the organisms in the past and relate them to the organisms in the present for understanding the process of evolution. We can also trace the time at which the organism existed.

4. State the significance of biochemical similarities among diverse organisms in evolution. [Delhi 2012]

Ans. Similarities in biochemicals such as DNA, helps in deriving the line of evolution. Organisms with more similar DNA sequences are considered close relatives or have evolved from the same ancestor,

1. Write the similarity between the wing of a butterfly and the w*ng of a bat. What do you infer

from the above, with reference to evolution? [Delhi 2012] or Comment on the similarity between the wings of a cockroach and the wings of a bird. What do you infer from the above, with reference to evolution? [All India 2012] or

Comment on the similarity between the flippers of dolphin and penguins, with reference to evolution. [Foreign 2012,2009]

Ans. Similarity between the wings of both the organisms is that they perform similar functions. They are thus, analogous organs. With reference to evolution, it can be inferred that these are result of convergent evolution

6.Name the scientist who disproved spontaneous generation theory. [Delhi 2010]

Ans.Louis Pasteur disproved the spontaneous generation theory.

7. Why are wings of butterfly and wings of bat called analogous? [Delhi 2009]

Ans. They are called analogous because they perform similar functions, but are dissimilar in their development and basic structure.

8. Mention the type of evolution that has brought the similarity as seen in potato tuber and sweet potato.[Delhi 2009]

Ans. Convergent evolution has bought the similarity as seen in potato tuber and sweet potato.

1. Are the thorn of Bougainvillea and tendrils of Cucurbita homologous or analogous? What

type of evolution has brought such a similarity in them? [HOTS; Delhi 2009] or

Are the wing of a bird and the forelimb of a horse homologous or analogous? Name the type of evolution that explains the development of such structures.[Foreign 2009]

Ans. They are homologous. Divergent evolution has brought this similarity in them

1. Name any two vertebrate body parts that are homologous to human forelimbs. [All India 2008]

Ans. Wings of birds and forelimbs of horses are homologous to human forelimb.

1. Name the placental mammals corresponding to the Australian spotted Cuscus and

Tasmanian tiger cat, which have evolved as a result of convergent evolution.[All India 2008 C]

Ans. Australian spotted cuscus – Lemur Tasmanian tiger cat – Bob cat.

2 Marks Questions

12.Identify the following pairs as homologous of analogous organs:

(i)Sweet potato and potato.