Q13 of 61 Page 1

(a) Give the evidence that the birds have evolved from reptiles.

(b) Insects, octopus, planaria and vertebrates possess eyes. Can we group these animals together on the basis of eyes that they possess? Justify your answer giving reason.

(a) Birds have evolved from reptiles. This is evident by a fossil bird named Archaeopteryx which has looks like a bird but the features have similarities with the reptiles such as it has feathers wings like birds but the teeth of Archaeopteryx look like those of reptiles. Thus Archaeopteryx connects reptiles and birds and it seems that birds have been evolved from the reptiles.


(b) No, we can’t group Insects, octopus, planaria and vertebrates on the basis of eyes because the eye structure is different in different organisms and thus suggests their separate origin of evolution.


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11

Draw diagrams to explain the regeneration that takes place in each of the body parts of planaria when its body is cut into three pieces. Name any other organism in which a similar process can be observed.

 12

List any four methods of contraception used by humans. How does their use have a direct effect on the health and prosperity of a family?

 14

A cross was made between pure breeding pea plants, one with round and green seeds and the other with wrinkled and yellow seeds.

(a) Write the phenotype of F1 progeny. Give reason for your answer.


(b) Write the different types of F2 progeny obtained along with their ratio when F1progeny was selfed.

 15

A spherical mirror produces an image of magnification -1 on a screen placed at a distance of 50 cm from the mirror.

(a) Write the type of mirror.


(b) Find the distance of the image from the object.


(c) Whatis the focal length of the mirror?


(d) Draw the ray diagram to show the image formation in this case.