13
How many times do nymphs moult to reach the adult form of cockroach?
Explanation
The nymph grows by moulting about 13 times to reach. In cockroach, the development is indirect and paurometabous adult form and has three stages. i.e., egg, nymph and adult. The nymph resembles adult except for undeveloped wings and genitalia.
14
Identify the sex of a frog in which sound producing vocal sacs are present.
Explanation
In amphibians, sex of frogs can be distinguished with the presence of sound producing vocal sacs. These organs are present in males which make them crock lauder, than females, so as to attract females for mating.
15
Name the process by which a tadpole develops into an adult frog.
Explanation
Tadpole undergoes metamorphosis to form adult.
16
What is the scientific term given to earthworm's body segments?
Explanation
Metamers is the scientific term given to earthworm's body segments.
17
A muscle fibre tapers at both ends and does not show striations. Name the muscle fibre.
Explanation
Smooth muscle fibres taper at both the ends (fusiform) and do not show striations. They are also called involuntary muscles.
