Ecdysozoa

Flashcards based on the key concepts and facts from the lecture notes on Ecdysozoa.

What is the defining characteristic of the clade Ecdysozoa?

Ecdysozoa is defined by molecular phylogeny and consists of 8 phyla.

Which two prominent phyla are part of Ecdysozoa?

Nematodes and Arthropods.

What is the function of the cuticle in ecdysozoans?

The cuticle acts as a barrier against desiccation and protects from mechanical injuries; it provides structural support as an exoskeleton.

What are the components of the ecdysozoan cuticle?

The cuticle is primarily composed of chitin in arthropods and collagen and glycoproteins in nematodes.

How many layers does the ecdysozoan cuticle have, and what are they called?

The cuticle consists of three layers: Endocuticle, Exocuticle, and Epicuticle.

What is sclerotization in relation to the arthropod cuticle?

Sclerotization involves cross-linking chitin polymers with proteins, resulting in a hardened and rigid cuticle.

What is the process of moulting in ecdysozoans?

Moulting involves shedding the old cuticle to allow for growth and can also facilitate regeneration of damaged tissue.

What are the steps of the moulting process?

The moulting process involves apolysis, secretion of moulting fluid, deposition of a new proto-epicuticle, activation of enzymes, deposition of a new procuticle, reabsorption of the moulting fluid, and finally shedding the old cuticle.

What is the ecological significance of free-living nematodes?

They play crucial roles in decomposition and nutrient cycling by feeding on microorganisms and decaying organic matter.

What diseases can nematodes cause in humans?

Nematodes can infect humans causing diseases like Trichinosis, filariasis, and Guinea worm disease.