flatworms

Question 1

what are platyhelminthes

Answer 1

small, short bodied worms

Question 2

what germ layer do flatworms have

Answer 2

tripoblastic 3 germ layer, causes organic system but with no coelum

Question 3

why is size and volume limited in a flatworm

Answer 3

because they are dependant on diffusion for water and gas exchange

Question 4

what type of symmetry do flatworms have

Answer 4

bilateral symmetry

Question 5

how many species of flatworm are there

Answer 5

30 000

Question 6

how many major classes and what are their names

Answer 6

4 major classes,
Turbellaria (5000sp), Trematoda (18 000sp), Monogenea (~6000sp), and Cestoda (6000sp)

Question 7

how does the epidermis in flatworms range

Answer 7

from multinucleated cells to syncytial

Question 8

how to most free moving flatworms move

Answer 8

by cilia beating in self-secreted mucus, and by muscular contractions

Question 9

how does Turbellaria get their name

Answer 9

by the whirling motion of cilia in mucus

Question 10

what does the very glandular epidermis secrete

Answer 10

specialised rhabdites (rod shaped), swell into mucous sheet in contact with water

Question 11

what happens when the anterior secretory cells are aggrivated

Answer 11

production of ‘glue’ to stick to surfaces

Question 12

how are flatworms bodies flattened

Answer 12

through the dorsoventral muscularate contracting and relaxing

Question 13

roles of epidermal pigmentation in flatworms

Answer 13

uv protection, camouflage, conspecific ID, possible warning mimicry

Question 14

what type of digestion system does flatworms have

Answer 14

incomplete, where the gut has numerous lateral branches

Question 15

how is undigested material excreted

Answer 15

through the pharynx

Question 16

what is the pharynx in flatworms

Answer 16

mid ventral, simple tube

Question 16

how does excretion and osmoregulation occur in flatworms

Answer 16

through cutaneous diffusion and via specialised functional units called protonephridia

Question 17

what are some types of asexual reproduction that flatworms do

Answer 17

fission and cloning

Question 18

how do most flatworms reproduce

Answer 18

clonally at some point by dividing and regenerating missing parts from neoblasts

Question 19

what is paratomy in flatworms

Answer 19

parent differentiates into chain of zooids before fission

Question 20

what is architomy

Answer 20

differentiation after fission

Question 21

what type of hemaphroditism does flatworms have

Answer 21

simultaneous, have both male and female parts at the same time

Question 22

what is internal fertilisation in flatworms

Answer 22

where the male gametes is inserted, is the norm

Question 23

what type of competitions do flatworms do to assume male role

Answer 23

penis fencing and hypodermic inpregnation

Question 24

what are the 2 types of eggs that can be laid

Answer 24

summer eggs that have thinner capsules, and resting eggs that have thick capsules. can resist freezing, drying and stay dormant