We dissect all sorts at this club, and today it was the turn of the Locust, a fairly large representative of the class Insecta.
Insects are Arthropods with jointed legs, segmented bodies and an exoskeleton made of chitin.
They have three body regions; the head, thorax and abdomen.
The main reason for dissecting insects for A level Biologists is to observe the Gas Exchange system. Locusts cannot get enough oxygen to their cells by diffusion alone. (Only fairly small organisms with a relatively large surface area to volume ratio can get enough oxygen through their surface) .
Insects have a simple tubular system in which oxygen can enter the body through holes called Spiracles, and can move down a concentration gradient through tubules called tracheoles to the respiring tissues.
Compression of the body brought about by the movements of the legs can aid gas exchange.
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