Chapter 32, and Sponges/Cnidarians

Question 1

Give a few characteristics of animals (11 possible)

Answer 1

Heterotrophic, nervous and muscle tissue, multicellular, tissues developed from embryoic tissues, eukaryotes, no cell walls, sexual reproduction, at least one larval stage, developmental (Hox) genes, all animals share a common ancestor

Question 2

Define bilaterally symmetric and give the unique traits, movement, and number of embryonic tissues

Answer 2

Have a dorsal/ventral side, a right/left side, and anterior/posterior ends

Most have nervous system located in the “head”
Can move faster than a radial organism
All are triploblastic

Question 3

Define radially symmetric and give the movement style

Answer 3

Have a top and bottom, but no front/back or left/right

Often sessile or planktonic

Question 4

Define ectoderm

Answer 4

Ectoderm covers the embryo’s surface

Question 5

Define endoderm

Answer 5

Endoderm lines the developing digestive tube

Question 6

Define diploblastic

Answer 6

Diploblastic animals have only ectoderm and endoderm

Question 7

Define triploblastic

Answer 7

Triploblastic animals have mesoderm as well as ecto/endoderm

Question 8

Define coelom. Which animals do not have a coelom?

Answer 8

a true body cavity derived from mesoderm

Include everything except roundworms, rotifers, and flatworms

Question 9

Define acoelomates. What group do they contain?

Answer 9

lack a body cavity

Include flatworms

Question 10

Define pseudocoelomates. What groups do they contain?

Answer 10

have a body cavity that is not lined with mesoderm (still functional)

includes roundworms and rotifers

Question 11

What is the function (3) of a body cavity?

Answer 11

Fluid that cushions the suspended organs and provides a ‘skeleton’ for muscles
Enables internal organs to grow and move independently of the outer body wall

Question 12

Protostome or Deuterostome?

Spiral and determinate cleavage

Answer 12

P

Question 13

Protostome or Deuterostome?

mouth develops from blastopore

Answer 13

P

Question 14

Protostome or Deuterostome?

anus develops from blastopore

Answer 14

D

Question 15

Protostome or Deuterostome?

solid masses of mesoderm split and form coelom

Answer 15

P

Question 16

Protostome or Deuterostome?

folds of archenteron form coelom

Answer 16

D

Question 17

Protostome or Deuterostome?

radial and indeterminate cleavage

Answer 17

D

Question 18

What animals are protostomes?

Answer 18

Flatworms (platyhelminthes), Rotifera, nematodes, most mollusca, most annelids, a few arthropods

Question 19

What animals are deuterostomes?

Answer 19

Echinodermata, Chordata, Most arthropods, a few molluscs and annelids

Question 20

What defines the eumetazoa clade?

Answer 20

having tissues

Question 21

What three major groups make up the eumetazoa clade?

Answer 21

deuterostomia, ecdysozoa, and lophotrochozoa

Question 22

What are the members of the deuterostomia clade?

Answer 22

Hemichordates (acorn worms), Echinoderms (sea stars), and Chordates

Question 23

What defines the ecdysozoa clade?

Answer 23

Secrete external skeletons, which are shed through ecdysis

Question 24

What defines the lophotrochozoa clade?

Answer 24

Feeding structures called lophophore
(horseshoe-shaped and ciliated)
and/or Distinct developmental stage of a trochophore larva (Short-lived)

Resemble corals

Question 25

What is the tissue type and symmetry of porifera?

Answer 25

Lack tissues and organs, asymmetrical

Question 26

Where are porifera in the phylogeny of animals?

Answer 26

They are the basal animals and the sister group to all other animals

Question 27

Describe the sexual traits of porifera.

Answer 27

Most are hermaphrodites

Question 28

What makes up the 'skeleton' of porifera (two types)?

Answer 28

Structural protein is collegen, a specialized form is spongin spicules are made of caco3 or si, and are used to classify sponges

Question 29

What is the ecological significance of porifera?

Answer 29

Symbiotic relationships with algae, bacteria, fish, and invertebrates Important members of shallow reefs, form deepwater reefs Boring sponges can injure coral

Question 30

What drugs come from porifera?

Answer 30

A chemotherapeutic drug for leukemia, Ara-C/cytarabine is derived from spongothymidine

Question 31

Define spongocoel

Answer 31

the central cavity of sponges

Question 32

Define osculum

Answer 32

the large opening where food exits in sponges

Question 33

Define choanocytes

Answer 33

the flagellated collar cells in sponges that make water currents and ingest food

Question 34

Define mesohyl

Answer 34

the gelatinous noncellular layer found between two cell layers in sponges

Question 35

Define amoebocytes

Answer 35

found in the mesohyl, move around and phagasitize food

Question 36

Describe the symmetry and tissue type of cnidarians

Answer 36

diploblastic, radial

Question 37

Where are cnidarians in the phylogeny of animals?

Answer 37

They are one of the oldest groups in the eumetazoa clade

Question 38

Describe the movement and forms of cnidarians

Answer 38

Sessile (polyps are stationary) Both polyp and medusa forms Advantages-> good at doing different things Jellyfish are only medusa

Question 39

What are the two major clades of cnidarians?

Answer 39

medusozoa and anthozoa

Question 40

What are the three clades of medusozoa?

Answer 40

hydrozoans, scyphozoans, and cubozoans

Question 41

What are the characteristics of medusozoans?

Answer 41

Dominant medusa stage

Question 42

What are the characteristics of hydrozoans? What are some examples?

Answer 42

Most alternate between polyp and medusa forms Hydra exists only in polyp form Portuguese Man-of-War looks like a jelly

Question 43

What are the characteristics of cubozoans? What are some examples?

Answer 43

Sea wasp | Highly toxic cnidocytes

Question 44

What are the characteristics of anthozoans? What are some examples?

Answer 44

include sea anemones and corals Only have polyp stage Symbiont with algae/dinoflagellates and secrete a hard CaCO3 exoskeleton

Question 45

Give some threats to coral reefs

Answer 45

Coral reefs are under threat from excess nutrients, siltation, overfishing, toxic chemicals, ocean acidification, and global warming

Question 46

Define gastrovascular cavity

Answer 46

central digestive compartment in cnidarians

Question 47

Define cnidocytes

Answer 47

cells that function in defense and capture of prey

Question 48

Define nematocysts

Answer 48

specialized organelles within cnidocytes that eject a stinging thread

Question 49

What are some characteristics of scyphozoans?

Answer 49

Coastal have a brief polyp stage, open ocean has none