Question 3 - Case Based Questions (including MCQ) - Chapter 9 Class 10 - Heredity and Evolution

Read the passage and answer the following questions.

There were three animals: A, B and C. The animal A can fly but animal B can only run on ground or walls. However, the forelimbs of animal A and B, both have same basic design but they were used for different purposes such as flying and running respectively. The animal C became extinct a long time ago. The study of fossils of animal C tells us that it had some features like those of A and some like those of B. In fact, animal C is said to form a connecting link in the evolutionary chain of A and B.

(a) The animal C is

(i) Trilobite

(ii) Archaeopteryx

(iii) Peripatus

(iv) Lamprey

Answer:

Archaeopteryx had feathered wings like those of birds and tail like those of reptiles . Archaeopteryx is therefore a connecting link between birds and reptiles and hence suggest that birds have evolved from reptiles 

So, the correct answer is (ii) Archaeopteryx 

(b) A belongs to _______ and B belongs to _________ group respectively.

(i) Birds, Reptile

(ii) Fish, Amphibian

(iii) Birds, Mammals

(iv) Fish, Reptile

Answer:

Archaeopteryx had feathered wings like those of birds and tail like those of reptiles . 

So, the correct answer is (i) Birds, Reptile 

(c) _____________ name is given to the forelimbs like those of A and B, which have the same basic design but different functions?

(i) Analogous organs

(ii) Homologous organs

(iii) Vestigeal organs

(iv) None of these

Answer:

Homologous organs are the organs that have the same structural plan and origin but have different functions.

So, the correct answer is (ii) Homologous organs 

(d) Which is the correct evolutionary chain involving A, B and C.

(i) C → A → B

(ii) B → C → A

Answer:

Archaeopteryx is therefore a connecting link between birds and reptiles and hence suggest that archaeopteryx(C) evolved from reptiles(B) and birds(A) evolved from archaeopteryx(C).

The correct evolutionary chain will be (ii) B → C → A 

(e) Select the correct statement.

(i) Tendril of a pea plant and phylloclade of Opuntia are homologous

(ii) Tendril of a pea plant and phylloclade of Opuntia are analogous

(iii) Wings of birds and limbs of lizards are analogous

(iv) Wings of bird and wings of bat are homologous

Answer:

Homologous organs are the organs that have the same structural plan and origin but have different functions.

Tendril of a pea plant and phylloclade of Opuntia are homologous because they have similar design and origin.

So, the correct answer is (i) Tendril of a pea plant and phylloclade of  Opuntia are homologous