NEET SHORT NOTES & TRICKS:
❇️PHYLUM - CTENOPHORA❇️👉They are commonly known as "Sea-gooseberries" or "Comb-jellies" or "Sea-walnuts
👉Bioluminescence (The property of a living organism to emit light) is well marked
👉 They are radially symmetrial,
Diploblastic organism with tissue grade body organisation
👉They are exclusively marine
👉Digestion is both extracellular and intracelluar
👉Locomotion takes place by the presence of 8 ciliary comb plates on the body surface.
👉Sexes are not separate. Reproduction takes place only by sexual means. Fertilization is external.
👉Development is of indirect type. Life cycle involves a free living Cydippid larval stage.
e.g. 1. Pleurobrachia
2. Ctenoplana
❇️PHYLUM - PLATYHELMINTHES❇️
👉They have dorsoventrally flattened body hence are called flat worms.
👉These are mostly endoparasites found in animals including human being but some are Free living (aquatic).
👉Excretion occurs through specialised cells called flame cells or Solenocytes(Protonephridia).
👉They also help in osmoregulation
👉Locomotary organs are absent in these animals but adhesive organs like suckers, hooks etc are present in
parasitic form.
👉Body is Bilaterally symmetrical and body organisation is of organ /organ system grade.
👉Body is Triploblastic
👉They are Bisexual.
👉Reproductive system is complex and well developed. Fertilization is internal.
👉Development indirect through many larva stages
👉Some members like Planaria possess high regeneration capacity
