Flashcards in The Exoskeleton And Metamorphis Deck (14)
What do you say the cuticle is when it’s brown in colour?
What is the exoskeleton made of?
Chitin, which is linked to a protein matrix giving tensile strength
Give an example of a ‘rubber-like’ cuticle and when it might be used
Resilin: it is like a mechanical spring when bent so is good after a large fluid intake (arthrodial membrane)
When does size gain occur in an insect?
At the moult
Give the four layers of cuticle secreted by the epidermal cells
Give the stages of the moult cycle:
1. Apolysis (cuticle still present but not attached)
2. New epicuticle forms
3. New exocuticle forms
4. Ecdysis (cuticle is moulted)
What are holometabolous insects?
Endopterygotes where they have immature stages called larvae and have a pupal stage
What are hemimetabolous insects?
Extopterygote where they have immature stages called nymphs e.g locusts
What are ametabolous insects?
Apterygotes where they undergo gradual or no metamorphosis e.g silverfish
What part of the cuticle is sclerotized?
What are the two hormones that determine whether an insect develops a larval, pupal or adult cuticle?
What hormone does an adult not have?
What does the ecdysis triggering hormone cause the insect to do?
Causes the insect to perform a stereotyped behaviour to shed the old cuticle