Terminology for animal diversity

• Symmetry in animals can be of three types: asymmetry, radial symmetry, and bilateral symmetry.
• Asymmetry in animals means the absence of symmetry, where an organism can be cut in any plane and will not have equal halves.
• Radial symmetry in animals means that the organism can only be cut lengthwise in many planes and will get equal halves.
• Bilateral symmetry in animals means that the organism has a definite head and a tail and can only be cut in the center, resulting in equal halves.
• Diploplastic refers to an organism that has two body layers, while triploblastic refers to an organism that has three body layers.
• The outer body layer in diploblastic organisms is the ectoderm, while in triploblastic organisms, it is the ectoderm, mesoderm, and endoderm.
• An acelomate organism does not have a true body cavity, while a celomate organism does have a true body cavity.
• Cephalization, a term that occurs only in bilateral organisms, is the concentration of a nervous system or sense organs in the anterior or the front part of an organism.
• A blind gut is when an organism has one opening for ingestion, while a blind gut with two openings is when an organism has two openings for ingestion and egestion.
• An open blood system is where blood flows through the blood vessels and then blood flows into an open cavity called the haemocoel, while in a closed blood system, the blood remains in the blood vessels and does not come into contact with the cells.
• Invertebrates do not have backbones or spinal columns.
• Vertebrates are animals with backbones or spinal columns.
• The phylum Chordata includes vertebrates, which have a dorsal nerve cord.
• Vertebrates are animals with a vertebral column (backbone).
• Echinodermata includes starfish, sea lilies, sand dollars, brittle stars, sea urchins, and feather stars.
• Chondrichthyes (cartilaginous fish) include sharks, rays, skates, and chimaeras.
• Chordates have a dorsal nerve cord, a hollow dorsal tube called a notochord, and a post-anal tail.
• The phylum Chordata includes vertebrates and some invertebrates (tunicates).
• Phyla Porifera and Cnidaria include both invertebrates and nonchordates.
• Osteichthyes (bony fish) include bony fishes such as salmon, trout, catfish, bass, perch, and tuna.
• Fish are aquatic animals that breathe by gills and lay eggs.
• Amphibia are cold-blooded animals with moist skin, lungs or gills, and three distinct life stages: egg, tadpole/larvae, adult.
• Birds are warm-blooded animals with feathers and lungs.
• Reptiles are ectothermic animals with dry scales on their skin and lungs.