Animals Flashcards
Animals are grouped into different ____ according to their ________
Phyla
Body plans
4 key feature of body plans
Body symmetry & cephalisation
Tissue layers
Number of openings in gut
Coelom
Name, explain & give an example of the 3 different body symmetry
Asymmetry - have no mirrored halves eg. sponges
Radial - body parts arranged around a central axis & can therefore be cut in any way to make mirrored halves eg: jellyfish
Bilateral - can cut it lengthwise to make mirrored halves eg: lobster
Cephalisation?
Nerve tissue is centralised in the anterior of the body
- makes them more aware of enviroment
Name 2 tissue layers & explain
Diploblastic - ectoderm & endoderm
Triploblastic - ectoderm, endoderm & mesoderm
What does the mesoderm allow?
Allows organism to develop organs
Name & explain 2 guts
Single - taking in food & excreting waste from same opening
Through gut - food taken in through mouth, digested and waste released from other opening
What does the through gut allow?
Specialization of parts along the tube
Name & explain 2 coelom types
Acoelomate - no body cavity ; body filled with cells
Coelomate - has a body cavity
Advantages of coelomate
Allows space for organs & organ systems
Allows peristalsis to occur
Name & give examples of the 6 different phyla
Porifera - sponges Cnidaria - jellyfish Platyhelminthes - flat worms Annelida - worms Arthropoda - insects Chordata - vertebrates
Body plan of Phylum Porifera
Asymmetrical Acoelomate No tissue layers Body supported by skeleton of minute spicules Digestion takes place intracellularly Excretion& respiration by diffusion
Body plan of Phylum Cnidaria
Radial symmetry Diploblastic tissue layers - with mesogloea between layers Digestive cavity with single opening - catch food with aid of tentacles with cniodcytes
Name & give examples of the 2 basic body forms of Phylum Cnidaria
Medusae - jellyfish
Polyps - sea anemone
Body plan of Phylum Platyhelminthes
Acoelomate Single gut opening Bilateral symmetry Cephalisation Triploblastic tissue layers
Body plan of Phylum Annelida
Bilateral symmetry Triploblastic Cephalisation Coelomate Two openings in gut
Body plan of Phylum Arthropoda
Bilateral symmetry Coelomate - replaced by a blood filled space called a haemocel; therefore have a open blood system Triploblastic Cephalisation Through-gut
Body plan of Phylum Chordata
same as arthropoda PLUS: Notochord Hollow, dorsal, tubular nerve chord Pharyngeal slits
