general zoology- unit 1

taxonomy

the system of classifying and naming organisms

systematics

classifying based on evolutionary considerations

1700’s taxonomy

Linnaeus- regnum animale, vegetabile, lapideum

1860’s taxonomy

Haeckel- plantae, animalia, protista

1920’s taxonomy

Copeland- Addition of Prokaryota and Monera (bacteria)

1960’s taxonomy

Whittaker- plant, animal, protest, fungi and monera kingdoms

1990’s taxonomy

domains of archaea, bacteria, and eukarya are introduced

porifera

metazoans=no tissue organization (cell grade) ex sponges

eumetazoans

“true animals” tissue, organ, or organ system grade

Body Plans

Spherical- typically unicellular

Asymmetry

Radial- body parts radiate from center ex- sea star, jelly

Bilateral- mirror image, associated with cephalization (having a head)

no gut cavity

single germ layer, sponges

gastrulation

when the single germ layer turns into several layers

diploblastic

two germ layers- jellyfish, corals

triploblastic

3 germ layers- 30 animal phyla

triploblastic- protostome

1st opening that forms (blastophore) is the mouth. snails and earthworms

triploblastic- deuterostome

1st opening that forms is the anus. seastars, fish, mammals

acoelomate

flatworms, no body cavity between digestive system and outer body wall

psuedocoelomate

roundworms, false body cavity, mesoderm only partially surrounds cavity

eucoelomate

earthworm, true body cavity

protostome- lophotrochozoa

lophophore- horseshoe shaped whorl (a feeding device), trochophore larva, EX- segmented worms, snails, slugs, octopus

protostome- ecdysozoa

ecdysis (shedding/molting), insects, crabs, roundworms

segmentation/metamerism

repetition of similar body segments

somite

each body segment. muscles, nerves, etc. repeated

species (biologically)

a population whose members can interbreed and produce offsprings

species (morphological)

a population whose classification is the same based on physical features

species (ecological)

identifies species based on ecological niches and adaptations

species (phylogenic)

smallest group of individuals that share a common ancestor

speciation

the process where one species splits into two or more

origin of species (Charles Darwin)

study of fossils and transitional forms over time, similarities between different organisms, later homology and DNA sequencing

natural selection (non-random selection)

species that are better adapted to the environment (niche) are more likely to live to pass on their genes, weaker species die and their genetics are minimized

influences of natural selection

change in environment, heritable variations, mutations, overproduction of offspring (creates competition)

how do species stay seperate

different habitats, breeding during different times of the year, dif. breeding rituals, physical incompatibility, molecular incompatibility

endosymbiont theory

cells engulfed each other or started a symbiotic relationship that gave an advantage, thus multicellular life. from mitochondria and chloroplasts having their own DNA and 2 membranes.