Ch.32

Question 1

Heterotroph

Answer 1

-ingest own food

Question 2

animals

Answer 2

-heterotrophs
-cells lack cell walls
-bodies held together by structural proteins (collagen)
-unique muscle and nervous tissue
-at least one larval stage
-made impact on land by 460 million years ago

Question 3

Tissues

Answer 3

group of cells that have a common structure, functon or both

Question 4

Blastula

Answer 4

-undergoes gastrulation (forms gastrula w/ different layers of embryonic tissues)

Question 5

advantage of sexual reproduction

Answer 5

increase genetic variation

Question 6

larva

Answer 6

sexually immature and morphologically distinct from adult
-undergoes metamorphosis

Question 7

ediacaran biota

Answer 7

period classification that consists of all life forms there present on Earth during ediacaran period
-included in early animal fossil record
-dates from 565 to 550 million years ago

Question 8

mesozoic era`

Answer 8

coral reefs emerged
-ancestors of plesiosaurs returned to water
-dinosaurs were dominant vertebrates
-first mammals emerged
-flowering plants and insects diversified

Question 9

Cenozoic era

Answer 9

-followed mass extinction of terrestrial/marine animals (large, nonflying dinosaurs)
-mammals increased in size and explored vacated ecological niches
-global climate cooled

Question 10

radial symmetry

Answer 10

some animals have no front/back or left/right
-often sessile or planktonic (drift/weak swimming)

Question 11

bilateral symmetry

Answer 11

two-sided symmetry
-move more actively
-have central nervous system

Question 12

cephalization

Answer 12

many sensory organs forming at the front end of body, forming a head

Question 13

ectoderm

Answer 13

germ layer covering embryos surface

Question 14

endoderm

Answer 14

innermost germ layer
-lines digestive tube (archenteron)

Question 15

diploblastic

Answer 15

-animal has both ectoderm and endoderm (cnidarians/comb jellies)

Question 16

triploblastic

Answer 16

-animal that also have an intervening mesoderm layer (include bilaterians)
-flatworms, arthropods, vertebrates, others
-most have body cavity (coelom)

Question 17

mesoderm

Answer 17

-formed through gastrulation
-middle layer between endoderm and ectoderm

Question 18

coelom

Answer 18

true body cavity
-derived from mesoderm

Question 19

coelomates

Answer 19

-animal that possess a true coelom

Question 20

pseudocoelomates

Answer 20

-triptoblastic animal that possess a pseudocoelum (body cavity derived from endo/ectoderm
-fluid filled body cavity not lined by mesoderm

Question 21

acoelomates

Answer 21

-triploblastic animals that lack body cavity

Question 22

protostome development

Answer 22

-cleavage is spiral and determinate
-blastopore becomes the mouth

Question 23

deuterosome development

Answer 23

-cleavage is radial and indeterminate
-mesoderm buds from wall of the archenteron to form coelom
-blastopore becomes anus

Question 24

blastopore

Answer 24

-forms during gastrulation and connects the archenteron to the exterior of gastrula
-makes digestive track

Question 25

Points in agreement

Answer 25

-all animals have common ancestor -sponages are basal animals -Eumetazoa is a clade of animals w/ true tissues -bilaterians (most animal phyla belong to clade Bilateria) -chordates and some other phyla belong to clade Deuterstomia

Question 26

ecdysozoans

Answer 26

-shed their exoskeletons through process called ecdysis

Question 27

lophotrochozoans

Answer 27

-lophophore -trochozoan larval stage

Question 28

lophophore

Answer 28

horse shaped structure with ciliated tentacles around mouth in certain marine invertebrates -feeding structure

Question 29

trochophore larva

Answer 29

distinct developmental stage in lophotrochozoans

Question 30

Phylogentic studies

Answer 30

-will likely provide further insights into animal evolutionary history

Question 31

vertebrates

Answer 31

-made transition to land around 360 million years ago

Question 32

body plan

Answer 32

set of morphological and developmental traits

Question 33

indeterminate cleavage

Answer 33

each cell in the early stages of cleavage retains the capacity to develop complete embryo -makes possible identical twins, and embryonic stem cells

Question 34

determinate cleavage

Answer 34

-mostly seen in arthropods, annelids, and mollusks (in most protosomes) -cell division in fertilized/unfertilized egg resulting in daughter cells that are no longer able to produce a complete embryo by themselves

Question 35

2 clades for morphology-based tree for bilaterians

Answer 35

-deuterostomes -protostomes

Question 36

recent molecular studies (contrasting 2 clades for bilaterians)

Answer 36

-indicate 3 bilaterians clades -deuterstomia -ecdysozoa -lophotrochozoa