Bio Lab 3

Question 1

phylum platyhelminthes

Answer 1

flatworms

Question 2

phylum nematoda

Answer 2

round worms

Question 3

Platyhelminthes and nematoda

Answer 3

• both are freshwater
• have a cellular mesoderm with an ectoderm and endoderm
• bilaterally symmetrical

Question 4

acoelomate

Answer 4

mesoderm is a solid mass of tissue with no cavity and no cavity for internal organs

Question 5

pseudocoelomates

Answer 5

have a body cavity called a pseudocoelom with a fluid space and a digestive tract

Question 6

flatworms are

Answer 6

acoelomate

Question 7

nematodes are

Answer 7

pseudocoelomates

Question 8

coelomate

Answer 8

have major organs suspended in a coelomic cavity completely surrounded by mesoderm

Question 9

triploblastic

Answer 9

have three embryological germ layers

Question 10

flatworms and roundworms have germ layers…

Answer 10

triploblastic

Question 11

flatworms and roundworms have ___ symmetry

Answer 11

bilateral symmetry with a distinct anterior and posterior end

Question 12

draw the body plants for flatworms and roundworms

Answer 12

there is a diagram

Question 13

Platyhelminthes

Answer 13

• have a gastrovascular cavity that is both mouth and anus (one opening)
• ladder like 2 spinal chords advanced nervous system
• are flat
• free living ones have ocelli called eyespots
• monoecious??

Question 14

class turbellaria

Answer 14

are hemaphroditic (have both fem and male organs) and are scavengers
- have eyespots that can sense light
- have a ciliated ventral surface
- mouth and anus are at the end of pharynx with intestinal diverticuli
(Platyhelminthes)

Question 15

species planaria (dugesia)

Answer 15

• free living

has sensory organs called eyespots and feed by sucking through a tubular pharynx that protrudes

Question 16

class trematoda

Answer 16

• parasites (both end and ecto)
• called flukes
• lack an epidermis but have a epicuticle made of protein and lipids to stop digestion
• ventral surface has an oral sucker
• often require intermediate hosts to distribute
  Platyhelminthes

Question 17

species opisthorchis

Answer 17

from Trematoda

• found in fish and snails
• more clear inside

Question 18

species fasciola

Answer 18

sucks blood (liver fluke)
- from trematoda
- uterus is near mouth, has a weird line through the middle
NOT LEECHES

Question 19

species shistosoma

Answer 19

FROM TREMATODA
(blood fluke)
causes disease schistosomiasis
- inhabits veins
- is hermaphrodic THE FEMALE FITS INSIDE THE CAVITY TO LAY THE EGGs

Question 20

intermediate host

Answer 20

harbours immature stages of parasite

Question 21

definitive host

Answer 21

harbours mature parasite

Question 22

class cestoda

Answer 22

Platyhelminthes

• anterior end called scolex, then neck then proglottids
• don’t have a gastrovascular cavity as nutrients come from host
• endoparasite
• mature packets called proglottids will detach and make larvae

Question 23

NEMATODA

Answer 23

• very diverse
  are slender with pseudocoelom and complete digestive tract
• use hydrostatic pressure to move
• complete GI tract with a mouth an anus
• can be free living and parasitic
• cause disease in humans like elephantiasis
• don’t require multiple hosts to survive

Question 24

species ascaris

Answer 24

nematoda

• have a hooked posterior end (anus)
• males are smaller
• to survive, they must pass through GI tract and have thick cuticle

Question 25

how did these organisms evolve?

Answer 25

Syncytial Theory AND Colonial Theory:

Question 26

Colonial Theory:

Answer 26

Evolved from flagellated protists; daughter cells failed to separate and were held together by an extracellular matrix. Evidenced by an extant colonial form of choanoflagellata (collared flagellates).

Question 27

SYNCYTIAL theory

Answer 27

Evolved from a multinucleated, unicellular slim mold or ciliated protist; evidenced by insect embryology.

Question 28

how evolved are they compared to others?

Answer 28

have three germ layers which is more evolved than cnidaria and porifera
- first group that has organs

Question 29

SA to Volume ratio

Answer 29

as you get bigger, SA ratio gets smaller

• they are long and slender or thin and flat
• must have a metabolism

Question 30

Platyhelminthes that are free living have eyespots called

Answer 30

ocelli

Question 31

increased body size means

Answer 31

more surface area

- must be thing and plat. long and slender

Question 32

diverticuli

Answer 32

inside the tubellaria, there are blind-ended branches in the gastrovascular cavity,

Question 33

trichinella

Answer 33

causes trichinosis (Nematoda)

females of Trichinella live in the intestine of their host and release lar- vae. These larvae migrate through the body to striated muscles, The larvae remain encysted until the muscle tissue is eaten by another host, where the larvae mature. Humans infect themselves by eating pork

Question 34

planaria movement

Answer 34

away from light due to eyespots

Question 35

mature proglottid

Answer 35

contains ovaries and testes

Question 36

gravid proglottid

Answer 36

contains eggs

Question 37

do mature or gravid proglottids occur closest to the scolex?

Answer 37

mature

Question 38

how do proglottis go in size as they near the end?

Answer 38

posterior end is larger

Question 39

nematode movement

Answer 39

only have longitudinal muscles (no circular or diagonal ones) so it moves by flipping and end.