All birds have

Which one of the followings in birds indicates their reptilian ancestry?

Consider the following four statements (a - d) about certain desert animals such as kangaroo rat.
(a) They have dark colour and high rate of reproduction and excrete solid urine
(b) They do not drink water, breathe at a slow rate to conserve water and have their body covered with thick hairs
(c) They feed on dry seeds and do not require drinking water
(d) They excrete very concentrated urine and do not use water to regulate body temperature.
Which two of the above statements for such animals are true?

Ornithorhynchus is an example of :

Silk thread is obtained from silk moth during

Radial symmetry occurs in which set?

Column I contains larval stages and Column II contains the group to which it belongs. Match them correctly and choose the right answer from the options given below:

Which one of the following statements is correct?

The figure shows four animals (a), (b), (c) and (d). Select the correct answer with respect to a common characteristic of two of these animals.
(a) (b) (c) (d)

The cross section of the body of an invertebrate is given below. Identify the animal which has this body plan.