Exam 1 review

Why protist are not metazoans

Protist are primarily unicellular organism

Challenges animals face in marine habitats

Climate change, pollution, and habitat loss

Challenges animals face in freshwater habitats

Unstable, changes occur often, smaller so influenced by extrinsic environmental factors

Challenges animals face in terrestrial habitats

Extreme temperature and water balance

What is used to construct phylogenetic trees

morphological (body shape), biochemical, behavioral, or molecular features of species or other groups. Then grouped by relationships among them

Protostomia

Have mouth forming first

Deuterostomia

Anus forming first

Spiralia

Undergo spiral cleavage

Ecdysozoa

All capable of molting

Echinodermata

5 radial symmetry

Hemichordata

Worm-like body, bilaterally symmetry and triploblastic in nature

Chordata

notochord and post anal tail

Saxitoxins

neurotoxins that cause paralytic shellfish poisoning

ribotoxins

fungal ribonuclease

Cephalization

Concentration of nerve tissue and sensory organs at the anterior end of an animal, creating a head region. ( encounter head first) Bilateral symmetry.

ex: Birds, snakes, lobsters, ants

Radial cleavage

Simple pattern of cell division that occurs in early embryonic development

Spiral cleavage

pattern of cell division that occur in flat and earthworm, snail

Acoelomate

organisms that have no true body cavities between the layers of their tissues

Pseudocoelomate

they have a body cavity, but it is not lined with mesoderm.

Eucoelomate

true body cavity