Question

1. The Big Picture: Identify the defining characteristics of the groups below, the names of the phyla, and 2-3 examples in each phylum.

• non-bilateral group - Sponges
• radially symmetrical:- Sea Jellies
• protostomes - lophotrochozoa, (focus on flatworms, mollusks, segmented worms)
• protostomes - ecdysozoa, (focus on roundworms and arthropods)
• deuterostomes: (focus on echinoderms and chordates)

Answer 1

1. Non bilateral group sponges-

phylum -Porifera

charactersitics -No body symmetry

as a larva they are motile and able to swim but as an adult they are sessile

no true tissue organization

Most of them reproduce sexually but some can reproduce by budding and regenration of fragment

they are majorly filter feeder but some can be carnivorus

Example - Clathrina clathrus , Hexactinellida

2 .Radially symmetrical-

Phylum-Cnidaria

charactersitics- radial symmetry

body multicellular , tissue grade organization , few organelles

both kind of reproduction is known asexual as well as sexual

Has simple net like nervous system

mostly carnivorus otherwise filter feeder examples-Hydra , sea wipes

3.Protostomes (lophotrochozoa )- it is a clade of protostome animals .

this consists of 2 groups trochozoans and lophophorata

trochozoans - the mouth develops before the anal  in the young embryo and they are mostly worms

the largest group in it are mollusca and annelida eg. earthworm

4. Ecdysozoa - it is one of the largest subdivision within the protostomia

it derived its name from the character of regularly shedding of its cuticle

most group of insects undergo partial or complete metamorphosis before reaching the adult stage and the larva look very different than their adult form and even live in completelly different environment

5.Echinoderms -

they have radial symmetry , many arms

The body actually consist of 5 equal segments each segment containing duplicate set of internal organs

they have no brain , heart,eyes but some brittle stars seems to have some light sensitive parts on their arms

they have tentacle like structure called tube feet with suction pads situated at their extremities

eg . Fromia monilis