Taxonomy and Asymmetrical animals

The Linnaean system

Binomial (genus and species)

Hierarchical (Kingdoms, phyla etc.)

Phylogeny

Evolutionary history of a species

Systematics

study of biology in evolutionary context

Cladistics

an examination of the prder in which organisms evolved - it draws phylogenetic trees called cladograms

Monophylogeny

a single common ancestor and all of its decendents

Paraphylogeny

single common ancestor and some of its decendents

Techniques for studying evolution

fossil examiation

Nucleic acid sequencing

Developmental biology

Genetic change

What did animals most likely evlove from?

Choanoflagellates

Parazoa

Porifera - sponges

Placozoa - flat animals

No tissue differentiation

Ectoderms (outer layer) contains

Cells of epidermis

Neuron of brain

Neuron of peripheral nervous system

Mesoderm (middle layer) contains

Cells of the notochord

Skeletal muscle cells

Kidney tube cells

Red blood cells

Endoderm (inner layer) contains

Pancreatic acinar cells

thyroid follicular cells

Lung alveolar cells

Difference between Protostomes and Deuterostomes

In protostomes, the blastopore becomes the mouth

In deuterostomes, the blastopore becomes the anus

Lophotrochozoa

lophophorates, annelids, molluscs

Ecdysozoa

All secrete a non-living cuticle e.g. arthropoda

Choanocytes

Collar cells that line the body cavity and have flagella that circulate water in sponges

Asconoid body plan of sponges

simplest radial form, tubular shape, small

Syconoid

Sponges have more elaborate foldings of the body wall

Leuconoid

sponges are highly folded, possesses flagellated chambers