Animal kingdom is classified into two subkingdoms.
- 1.It is made of only one cell.
2.have one or more nuclei in cytoplasm.
3.the metabolic activities like digestion,respiration,excretion ,reproduction performed by single cell.
4.Respiration & excretion by diffusion.
Ex; Amoeba,euglena etc..
B)Multicellular animals :
Phylum Porifera : Term Porifera coined by Robert grant& animal nature established.
1.sponges found in marine water have pores in their body wall called Ostia.These pores are numerous into a central cavity spongocoel & opens out through osculum.
2.Sponges used as sound absorber.
3.Skeletomade up of calcareous or silicon spicules.
4,Fresh water sponges- spongilla
5. Radially symmetrical or Asymmetrical.
6. Food is stored in thesocytes.
Ex: Sycon,sponge etc..
4.sea anemones are biradially symmetrical.
5.tissues appeared for the first time.
6.Around the mouth some thread like structures called tentacles help in holding the food.
7.cnidoblasts useful for Anchorage,defence & capture of prey.
8.coral forming cnidarians have exoskeleton made of CaCO3.
9.neurons are non- polarised.
10.mouth serve both ingestion& egestion..no anus.
Ex: 1.hydra ,Adamsia(polyp)sessile& cylindrical form.
2. Medusa is umbrella shaped & free swimming form(ex: Aurelia).
Phylum cnidaria classified into threee classes - a)Hydrozoa b)Scyphozoa.C)Anthozoa.
D)Phylum Ctenophora :1.commonly know as sea walnuts,or comb jellies.
3.diploblastic& tissue level.
4.biradial is a type of radial symmetry.
5.ciliated comb plates in locomotion.
6.lasso cells help in food capture.
This phylum classified into two classes-a)Tentacles- ex .pleurobranchia& hormiphora. b)Nuda- ex.beroe- tentacles absent.
E)Phylum Platyhelminthes :
- first bilaterally symmetrical.
- mesoderm first appeared in platy helminthes.
- body cavity is absent.
- dorsoventrally flattend animal .hence flatworms.
- Alimentary canal single opening no anus.
- moderate cephalization (first time).
- body is not segmented.
- Tapeworms - pseudo metamerism.
- excretion by flame cells.
- protonephridia helps in osmoregulation & excretion.
- fertilization is internal
- Development is indirect - miracidium,sporocyst,redia, cercaria .
phyium platyhelminthes is classified into 3 classes