2/5/20

Question 1

Phylum known for flatworms

Answer 1

Phylum Platyhelminthes

Question 2

characters shared by Phylum Platyhelminthes

Answer 2

30000 species, no circulatory or respiratory tissue, acoelomate, nervous system concentrated in head area, most have a blind gut, most are parasitic

Question 3

four key classes in Phylum Platyhelminthes

Answer 3

Trematoda, Monogenea, Cestoda, and Turbellaria

Question 4

a single grouping that doesn’t include all descendants of an ancestor

Answer 4

Paraphyletic grouping

Question 5

____ is paraphyletic to the rest of Platyhelminthes

Answer 5

Turbellaria

Question 6

class of Platyhelminthes known as true flatworms

Answer 6

class Turbellaria

Question 7

characters of class Turbellaria

Answer 7

4500 species, generally small, mostly aquatic (can be terrestrial in the tropics), epidermis covered in cilia

Question 8

organs present in Turbellaria

Answer 8

muscular pharynx, intestines, flame cells

Question 9

purpose and function of flame cells

Answer 9

osmoregulate the body; flagella beat, drawing body fluids into a tubule where salts are added/removed as needed

Question 10

method(s) of reproduction in Turbellaria

Answer 10

fission or sexual reproduction (where hermaphrodite pairs fight to see who inseminates who)

Question 11

class of Platyhelminthes known as flukes

Answer 11

class Trematoda

Question 12

characters of class Trematoda

Answer 12

18000+ species, parasitic, at least two hosts during life cycle, produce glycoproteins to protect from host immune system, oral suckers attach to organs, ventral suckers attach to tissue

Question 13

class Trematoda does/doesn’t have a digestive system (why?)

Answer 13

does. Trematoda often lives in non-digestive tissue (i.e. pancreas, lungs, liver), so digestion must occur in the parasite

Question 14

Trematoda (general) lifecycle

Answer 14

adult parasites reproduce in definite host (often a vertebrate), then release miracidium through the host excretory system, which reproduce asexually once in the intermediate host (often a mollusk). miracidium develop into cercariae, which once in definitive host mature into adults.

Question 15

miracidium

Answer 15

ciliated larvae produced by Trematoda

Question 16

class of Platyhelminthes known as monogenetic flukes

Answer 16

class Monogenea

Question 17

characters of class Monogenea

Answer 17

1100 species, all parasites (often ectoparasites on fish), only one host during life cycle, uses opisthaptor to attach to host

Question 18

opisthaptor

Answer 18

posterior adhesive organ of Monogenea

Question 19

class Monogenea does/doesn’t have a digestive system (why?)

Answer 19

does. Monogenea often lives on outside of fish body, so the parasite must be able to perform digestion within its body

Question 20

class of Platyhelminthes known as tapeworms

Answer 20

class Cestoda

Question 21

characters of class Cestoda

Answer 21

6000 species, all endoparasites, typically use vertebrates as definitive host, several meters long, skin is a syncytium to protect from host immune system, hermaphroditic

Question 22

class Cestoda does/doesn’t have a digestive system (why?)

Answer 22

doesn’t. Cestoda live in host intestines, so food has already been broken down into useful nutrients.

Question 23

how Cestoda grow/develop

Answer 23

proglottids are produced at the scolex and mature as they develop, with oldest proglottids at the end of the tapeworm and youngest closest to the scolex

Question 24

proglottids

Answer 24

segments in Cestoda

Question 25

scolex

Answer 25

head of Cestoda covered in barbs and suckers to attach itself to host’s intestine

Question 26

Phylum known as segmented worms

Answer 26

Phylum Annelida

Question 27

characters of Annelida

Answer 27

22000 species, mostly marine (can be freshwater or terrestrial), mostly free-living, body formed by metamerisms, major developmental advances

Question 28

metamerism

Answer 28

segmentation

Question 29

developmental advances seen in Annelida

Answer 29

closed circulatory system (uses hemoglobin to transport oxygen and other nutrients), nervous system (nerve chord on ventral side), true coelom (internal space highly compartmentalized), longitudinal and circular muscles (increased mobility), and advances excretory system

Question 30

function of excretory system of Annelida

Answer 30

each segment has pair of nephridia to remove waste from bloodstream and coelom, nephostrome draws fluid into nephridia which then empties out through nephridiopore

Question 31

three important classes of Annelida

Answer 31

Clitellata, Sedentary polychaetes, and Polychaete worms

Question 32

characters of class Clitellata

Answer 32

all hermaphrodites, mutual sperm transfer and reproduction, 4 setae per segment that allow for locomotion

Question 33

characters of Sedentary polychaetes

Answer 33

tubeworms, have large crown of ciliated tentacles used for feeding, primarily filter-feeders

Question 34

characters of polychaete worms

Answer 34

2/3 of all Annelids, mostly marine, found at all ocean depths, predatory