How many ova does a female frog lay at a time?

In which of these structures is collagen fibers present in rows between parallel bundles of fibers?

Which of these describes the skin of frog?

What is the shape of the seventh sternum of the female cockroach?

Which of the following structures represent the nervous system of an earthworm?

What is the main role of setae in earthworm?

Where are the calciferous glands of the earthworm present?

How many ganglia lie in the thorax and abdomen respectively in cockroach?