Question

1. Provide 2 examples and 2 characteristics of ecdysozoans.

typed answer please.

thank you.

Answer 1

1. Ecdysozoan is defined in 1997 on the basis of phylogenetic tree based on 18S ribisomal genes,"as group of protostome animals which includes Anthropoda, Nematoda, and phyla." but later in 2008 it is defined as clade i.e a group which consists of common ancestors and descendents given by Dunn et al.

2. Charatcters

- Ecdysozoan is a three layered cuticle composed of organic material, which is molted as animal grows this process is known as ecdysis.

- Ecdysozoan lack locomotary cilia, they produce amoeboid sperms.

- As we observed in most protostome, embryose undergo spiral cleavage but in ecdysozoan does not undergo spiral cleavage.

3. Examples

- Nematods comes under anthropoda group. These are tubular in shape and they do not posses true coelom. Nematods do not have well developed excretory system but have complete digestive system. Nematods have ability to shade their cuticle.

- Anthropods have segmented body divided into regions called tagma. Anthropods have open circulatory system.