T15

Question 1

what makes an organisms an animal?

Answer 1

all animals are heterotrophic - must eat something to gain energy

animals store carbohydrate energy as complex branched sugars called glycogen

are multicellular

no cell walls

have specialised cell junctions to allow for communication

nerve cells - specialised cell types to sense and respond to environment

muscle cells - cells that can convert chem energy to movement

undergo distinct development , coordinated cell to cell interaction

have germline- produce gametes

Question 2

early origins of life

Answer 2

first trace bacterial life - 3.7 bya

eukaryotes - 2bya

first ‘animals’ 700mya

most recognisable animals - 540mya

fairly recent the evolution of animals

Question 3

fossil records
lantian biota

Answer 3

600mya in china, possible animal fossil with tentacle like structures

Question 4

fossil records Burgess Shale

Answer 4

505mya showing fossil records from cambrian period, as potentially a collapsed marine

Question 5

Cambrian period

Answer 5

538mya
the time when many kinds of invertebrates and the first vertebrates—fishes—appeared in the fossil record.

Question 6

metazoa

Answer 6

animal grouping in phylogenetics

Question 7

major clades of metazoa

Answer 7

Porifera-sponges

placozoa

diploblasts - cnidaria and cteniphora - combo jellies and jellyfish

triploblasts - all other animals

Question 8

diploblasts

Answer 8

having a body developed from only two germ layers (ectoderm and endoderm)

Question 9

triploblasts

Answer 9

Triploblastic animals are the ones with three germ layers (a mesoderm as well as ectoderm and endoderm). The mesoderm allows them to develop true organs.

Question 10

evidence that suggests choanoflagellates are closely related to animals

Answer 10

1. morphologically choano and collar cells of sponges look very very similar
2. similar collar cells found in other animals
3. DNA sequences indicates they are sister groups

Question 11

superphyla of triploblasts

Answer 11

deuterostomia
ecdysozoa
lophotrochozoa

Question 12

deuterostomia

Answer 12

animals that form their mouth from a secondary opening during development

• echinodermata, chordata, hemichordate

all deutrosomes

Question 13

ecdysozoa

Answer 13

animals that moult their cuticles

arthropods, nematods, tardigrada, onychophora

all protostomes

Question 14

lophotrochozoa

Answer 14

animals with a lophophore feeding apparatus (cilitaed mouth) or a trochophore larva

annelida, mollusca, brachiopds

all protostomes

Question 15

deutrosomes

Answer 15

their anus forming before the mouth during embryonic development.

Question 16

protostomes

Answer 16

a mouth develops before the anus in embryos, true tissues, and are bilaterally symmetric.