bio L quiz 6

Question 1

why are sponges the most primitive animals

Answer 1

They lack true tissues, symmetry, and a coelomic plan.

Question 2

how do sponges obtain food

Answer 2

nutrients in the water are trapped in a sticky mucus at the base of the flagellum of a collared cell. They’re digested in the vacuoles of the collared cells and passed into other cells.

Question 3

3 advances cnidarians have over sponges

Answer 3

True tissue, radial symmetry, 2 distinct tissue layers

Question 4

what phylum has radial symmetry

Answer 4

cnidaria

Question 5

obelia life cycle

Answer 5

Life cycle alternates between polyp and medusa stages. Polyps reproduce asexually by budding and medusae produce gametes that form a zygote which then develops into a planula.

Question 6

symbiotic relationship in corals

Answer 6

They live in symbiosis with algae and photosynthetic protists. Photosynthetic organisms provide coral with nutrients during the day.

Question 7

3 advances flatworms have over cnidarians

Answer 7

3 distinct tissues: ectoderm, mesoderm, endoderm; cephalization, and bilateral symmetry

Question 8

how does bilateral symmetry allow cephalization

Answer 8

it allows the development of a distinct head region where sensory organs and nerve tissue can concentrate

Question 9

hydra vs planarian gastrovascular cavities

Answer 9

Planarians have a more advanced gastrovascular cavity because branching allows greater surface area for absorption of nutrients. Hydra has an unbranched gastrovascular cavity.

Question 10

How does a tapeworm attach to a host

Answer 10

using hooks and suckers on the scolex

Question 11

how do tapeworms feed and grow

Answer 11

They absorb nutrients through their body surface. Proglottid develops male and female organs.

Question 12

what are the 3 phylums in the last lab

Answer 12

porifera, cnidaria, platyhelminthes

Question 13

pseudocolemate

Answer 13

body cavity partly lined by mesodermal tissue and partly by endodermal tissue

Question 14

4 phylums in next lab

Answer 14

nematoda, mollusca, annelida, arthropoda

Question 15

are the animals in the next lab protostomes or dueterostomes

Answer 15

protostomes

Question 16

what kind of coelom do nematodes have

Answer 16

psuedocoelom

Question 17

what kind of coelom do molluscs, annelids, arthropods have

Answer 17

true coelom

Question 18

what advantage does a pseudocoelomate body have over an acoelomate

Answer 18

it provides a space where organs can lie

Question 19

osculum

Answer 19

central cavity in sponges where water exits

Question 20

ephyra

Answer 20

juvenile jellyfish

Question 21

cnidocytes

Answer 21

stinging cells in cnidarians