2- Platyhelminthes and Annelids

Question 1

flatworms; consists of free-living and parasitic organisms

Answer 1

platyhelminthes

Question 2

characteristics of platyhelminthes

Answer 2

• bilateral symmetry
• definite polarity of anterior and posterior ends
• dorsoventrally flattened body
• highly organized nervous system

Question 3

platyhelminth class: mostly free-living w a ciliated epidermis

Answer 3

turbellaria

Question 4

platyhelminth class:
- monogenetic parasitic flukes
- attach to host w hooks

Answer 4

monogenea

Question 5

platyhelminth class:
- digenetic flukes
- lacks hooks
- parasitic in all vertebrate classes

Answer 5

trematoda

Question 6

platyhelminth class:
- tapeworms
- scolex w suckers or hooks
- no digestive organs
- digestive tract parasite in all vertebrate classes

Answer 6

cestoda

Question 7

segmented worms

Answer 7

annelida

Question 8

characteristics of annelida

Answer 8

• bilaterally symmetrical
• tubular body is divided into annuli
• exhibit metamerism or true segmentation

Question 9

ringlike segments in tubular body of annelids

Answer 9

annuli

Question 10

annelid class:
- marine segmented worms
- most are dioecious

Answer 10

polychaeta

Question 11

annelid class:
- freshwater and earthworms
- hermaphroditic
- less developed heads and setae

Answer 11

oligochaeta

Question 12

annelid class:
- leeches
- most are bloodsucking parasites of vertebrates
- lack setae

Answer 12

hirudinea