Answer The Following question.

Question 13 Marks

How many and which are the stages of evolution of animals?

Answer

There are two stages of evolution of animals. They are:

Invertebrates: These are animals without a backbone.
Vertebrates: Animals which have a backbone are vertebrates. Aquatic animals, amphibians, birds, reptiles and mammals are all vertebrates.

Question 23 Marks

How did birds form from dinosaurs?

Answer

Dinosaurs became extinct because of some sudden natural disaster or environmental change
Fossils of dinosaurs with wings have been discovered
It is thus believed that some species of two legged and winged dinosaurs evolved into birds.

Question 33 Marks

How did various classes of plants and animals come into being?

Answer

Life on earth began with unicellular organisms known as protozoa.
These unicellular organisms gave rise to multicellular living things.
Multicellular organisms evolved gradually and thus various classes of plants and animals came into being

Question 43 Marks

Give the characteristics of mammals.

Answer

The characteristics of most of the mammals are as follows:

EVS Answer The Following question.