Practical 8: KINGDOM ANIMALIA (INVERTEBRATES, CHORDATES and VERTEBRATES).
• To recognize representatives of invertebrates, chordates and vertebrates.
• To explain the basic body plan of invertebrates, chordates and vertebrates.
• To identify the structures found in the animal groups and their function.
Animals are multicellular, oxygen-consuming, heterotrophic organism that exhibits considerable motility. Animals are divided into two which are vertebrates and invertebrates. Phylum Chordata consists of a majority of species that are vertebrates (with a backbone) and minority are invertebrate. Most animal are diploid and reproduce sexually, although asexual reproduction is common. The animal life cycle includes a period of embryonic development. During this stage, three primary germ layers which are ectoderm, mesoderm and endoderm form and give rises to adult tissues.
Invertebrates lack an internal skeleton made of bone. Many invertebrates have a fluid-filled, hydrostatic skeleton such as jelly fish or worm. Besides that, some of them have a hard outer shell, like insects and crustacean. Chordates are deuterostome coelomates with bilateral symmetry. All chordates have the following features at some point in their life, a notochord and gut and function as their nervous system. Besides that a pharynx that has gill slits that functions in feeding, respiration or both and a post anal tail that exists near the anus.
The vertebrates take over as it goes higher in animal category. The vertebrates can be distinguished from other chordates by having backbones or vertebral column. Fish, reptiles, amphibians, birds and mammals are the member of vertebral column. The vertebrates can be distinguished from other chordates b having backbones or vertebral column.
8.1.1 Phylum porifera
Preserved specimen of sponge
1. The sponge is observed.