Question

The development in Periplaneta americana is:
A. Holometabolous
B. Paurometabolous
C. Ametabolous
D. Hemimetabolous

Answer 1

Hint: Periplaneta americana is the scientific name for cockroach. The cockroach develops through gradual metamorphosis passing through the nymphal stage.

Complete answer:
To solve the question, we must know how the development of cockroaches occurs.
Periplaneta americana, commonly known as the cockroach belongs to Phylum Arthropoda and Class Insecta. It has a segmented body which is majorly divided into head, thorax and abdomen. Its developmental process is quite unique.

The nymphal stage develops into an adult by a process known as ecdysis or moulting. Ecdysis is the phenomenon where the insect continuously sheds its exoskeleton. It is a periodic phenomenon. The cockroach nymph undergoes ecdysis almost 13 times to metamorphose into an adult. This type of development is known as paurometabolous development.

Therefore, the correct answer to this question is paurometabolous.

Paurometabolous development is nothing but gradual metamorphosis. In this type of development the nymphs look similar to the adults. Their habitat and food habits are also similar to adults.

Additional Information: In ametabolous development, there is no metamorphosis and the young ones bear similarity with the adults. But they do not have genitalia.
Complete metamorphosis is also known as holometabolous development. This type of metamorphosis is found in butterflies.
Hemimetabolous development is the one in which the incomplete metamorphosis takes place.

Note:
The paurometabolous development should not be confused with the ametabolous and the hemimetabolous development. Although in all these developments the nymph shows resemblance to the adult.