Arthropods 2 Flashcards
What is chitin?
Arthropod cuticle
Chitin is a key component of the exoskeleton in arthropods.
What role does protein play in the arthropod cuticle?
Provides strength; forms exoskeleton
What compounds contribute to the rigidity and strength of the arthropod cuticle?
Phenolic compounds, specifically phenoloxidase
What is the purpose of the waxy layer in insects?
Waterproofs; secreted to top of cuticle
What protects the wax layer in the arthropod cuticle?
Cement layer
What structure locks twisted microfibrils in the arthropod exoskeleton?
Exoskeleton
What are the key features of the arthropod exoskeleton?
Muscular jointed limbs, flight, jaws, claws
What process must arthropods undergo to grow?
Moulting
What is moulting also known as?
Ecdysis
What percentage of Anax imperator (dragonfly) fail to emerge during moulting?
5.5%
What hormones control moulting in arthropods?
20-hydroxyecdysone and Juvenile hormone
What is pupation and metamorphosis associated with in arthropods?
Endopterygotes
What does the radial reorganisation of body structure in arthropods allow?
Exploitation of different niches
How does arthropod respiration evolve?
Gills, book gills, lung books, lungs, tracheal network
How is oxygen delivered to muscle fibres in insects?
Via branching trachea and tracheoles
What is the role of spiracles in insect respiration?
Cause discontinuous gas exchange; valves on surface of insect’s body
What are the four main classes of arthropods?
- Crustacea
- Insecta
- Chelicerata
- Myriapoda
What is a characteristic of arthropods related to their exoskeleton?
Hard exoskeleton requires ecdysis to grow
What type of circulatory system do arthropods have?
Open circulatory system (haemocoel)
What is metameric segmentation in arthropods?
Adaptability of body plan
What is tagmosis in arthropods?
Segments grouped into structurally similar regions
What is the common ancestor of arthropods referred to as?
LUCA (Last Universal Common Ancestor)
What are the three body sections of Insecta?
- Head (1 pr antennae)
- Thorax (3 prs legs)
- Abdomen (no legs)
What are the three body sections of Crustacea?
- Head (2 prs antennae)
- Thorax (legs etc.)
- Abdomen (legs)
