question_answer

(i) ?Planaria, insects, octopus and vertebrates all have eyes. Can we group eyes of these animals together to establish a common evolutionary origin? Justify your answer.

(ii) ?Birds have evolved from reptiles?. State evidence to prove the statement.

Answer:

(i) The eyes seen in each of these organisms vary differently in their structure but all of them    perform the same function of vision. Thus a common evolutionary origin can be established on the basis of eyes.

(ii) ?Birds have evolved from reptile" this can be justified as follows:

(a) Fossils of certain dinosaurs or reptiles shows imprints of feather along with their bones but they could not fly presumably using the feathers for insulation.

(b) Later, they developed and adapted feathers for flight, thus becoming the ancestors of present day birds. During fever, taste buds do not work properly and as a result, taste of the food eaten is not felt properly thus enzyme secretion is also affected.

When a person is suffering from a cold, the nostrils are filled with mucus.