Phylum Platyhelminthes

Question 1

bilateral symmetry

Answer 1

having two well-formed sides

Question 2

scavengers

Answer 2

to feed off dead animals

Question 3

hermaphrodites

Answer 3

having both male and female reproductive organs

Question 4

flukes

Answer 4

class Trematoda

Question 5

Platyhelminthes

Answer 5

flatworm

Question 6

fission

Answer 6

reproduction by splitting in half

Question 7

cephalization

Answer 7

having a head

Question 8

pharynx

Answer 8

muscular tube for drawing in food near the mouth

Question 9

proglottids

Answer 9

segment of tapeworms body

Question 10

acoelomates

Answer 10

lacking a body cavity, without coelom, digestive cavity is lined with endoderm.

Question 11

class Cestoda

Answer 11

tapeworm

Question 12

diffusion

Answer 12

mechanisms for respiration, exception and circulation

Question 13

flatworm

Answer 13

soft bodied, few millimetres thick, have tissues and internal organs, three embryonic germ layers. bilateral symmetry.

Question 14

feeding

Answer 14

single opening for mouth and anus. near the mouth is a muscular tube called the pharynx, pharynx extends out of the mouth to pump into digestive cavity. digestion and absorption takes place in the gut. nutrients diffuse to other parts of the body.

Question 15

carnivores

Answer 15

preying on aquatic animals

Question 16

parasitic worms

Answer 16

feed on blood, tissue fluids or pieces of cells. feed on already a digested food, simple digestive system.

Question 17

respiration, exception and circulation

Answer 17

rely on diffusion to transport oxygen and nutrients throughout. rely on diffusion to remove waste products and Co2, lacks gills or other respiratory organs. lack heart, blood vessels and blood. flames cells are found in flat worms. for excretion of excess water. they are joined in a. network of tubes that empties to outside environment through pores in skin.

Question 18

response

Answer 18

head encloses several ganglia which controls nervous system. has two longitudinal nerve cords along length of body connected by several shorter longitudinal Neve cords across the body. many flatworms have eyespots that detect changes in amount of light. also have specialized cells for detecting other external stimuli scattered throughout body located food and find dark hiding places.

Question 19

movement

Answer 19

movement via cilia on epidermal cells facilitating gliding through waters and over surfaces. muscle cells enable turning and twisting.

Question 20

reproduction

Answer 20

most free living flatworms are hermaphrodites meaning they have both male and female sex organs. during reproduction, two worms join to exchange sperm with one another. asexual reproduction occurs with fission, splitting in two. some species of worms “fall in pieces” with each smaller piece regenerating to become new individuals.

Question 21

group of flatworms, three groups include:

Answer 21

turbellarians, flukes and tapeworms.

Question 22

turbellarians

Answer 22

free-living flatworms, live in marine or freshwater, bottom dwellers in sand or mud under stones or shells. most familiar are planarians -> cross-eyed freshwater flatworm

Question 23

flukes

Answer 23

class Trematoda, parasitic flatworm found in any internal organs or blood of host. some are may be external parasites found on skin, mouth, gills or other outside body parts.

Question 24

tapeworms

Answer 24

class Cestoda, long, flat. parasitic worm found in intestines of host. digested food of host is absorbed directly into body of tapeworm.

Question 25

structure of a tapeworm

Answer 25

head has scolex which contains suckers or suckers for anchoring onto hosts intestinal walls. behind scolex is a narrow region that divides into proglottids segments of the tapeworms body. tapeworms can fertilize their own eggs or other individuals eggs.

Question 26

planaria

Answer 26

class turbelleria

Question 27

ganglia

Answer 27

collection of nerve cells

Question 28

cyst

Answer 28

dormant larval stage of tapeworm

Question 29

parasite

Answer 29

obtaining nutrients from a host