Question

5A. How are the pterygots different from the jumping bristletails and silverfish?

5B. Describe three ways in which insects are different from other hexapods.

Answer 1

ANS. 5A. Pterygots are different from jumping bristletails and silverfish in the way of presence or absence of wings. pterygots are the insects of the subclass "Pterygota" that have wings and also includes other order of insecta that lost their wings as a result of evolution but their ancestors were winged.

Bristletails comes in the order "Archaeognatha" and silverfish is of the order "Zygentoma". these two orders are wingless from their ancient times and never had wings. therefore, in this context they are different from Pterygota.

ANS. 5B. Three ways in which insects are different from other hexapods -

• insects are a diverse group of organisms under the phylum Arthropoda. it constitues the largest class in arthropoda - comprises of exoskelton, wings and paired appendages. hexapoda is a large sub-phylum which includes insects or non-insects having six legs (hexa = six).
• hexapods in general is the term given to any organism bearing 6 legs or appendages. they are different from insects in a way that not all insects have 6 appendages but all hexapods will definitely have 6 feet.
• body of insects is divided into three parts - head, thorax, and abdomen. while it is not there in the case of hexapods.