Worms

Question 1

what type of larvae do annelids have?

Answer 1

Trochophores

Question 2

What type of symmetry do worms have?

Answer 2

bilateral

Question 3

What are characteristics of platyhelminthes?

Answer 3

Bilateral symmetry
– Three tissue layers
– Central nervous system with brain (ganglia)
(cluster of nerve tissue in head)
– Incomplete digestive tract: gut without anus
– Many are marine: free-living flatworms,
parasitic flukes, and tapeworms.
– No body cavity
– Hermaphroditic

Question 4

What are characteristics of Class Turbellaria?

Answer 4

Free living flatworms
Mostly non-parasitic

Question 5

What are characteristics of Class Monogenea?

Answer 5

fresh and marine parasites
external parasites of fish
simple life cycle

Question 6

What are characteristics of Class Trematoda?

Answer 6

Internal parasites of molluscs and vertebrates
- 1 or more suckers
- Complex life cycle with two hosts
- Mollusc host first – miracidium enter host
- Vertebrate host second - cercaria dispersed and
penetrate second host

Question 7

What are characteristics of Class cestoda?

Answer 7

tape worms
mostly hermophrodites

Question 8

What are Nemertea?

Answer 8

Ribbon worms

Question 9

What are plathelminthes?

Answer 9

flatworms

Question 10

What are characteristics of Nemertea?

Answer 10

Proboscis – capture prey with venom
- Rhynchocoel – surrounds proboscis
- Reduced body cavity
-** Circulatory** system
- Many are poisonous/taste bad
- Separate mouth and anus

Question 11

Why is being flat an advantage to some worms?

Answer 11

– **no circulatory system; **
diffuse oxygen &
nutrients directly into the cell

Question 12

What is a proboscis?

Answer 12

structure in ribbon worms.
they compress their bodies to push out the **proboscis

Question 13

What are nematoda?

Answer 13

roundworms

Question 14

What are characteristics of nematoda?

Answer 14

Free living and Parasitic
- Only longitudinal muscles
- Pseudocoelom
- Circular
- Cuticle – outer case (molts case to grow)

Question 15

What is the life cycle of nematoda?

Answer 15

Larval stages are found in fish and can be** passed** to humans if raw (or undercooked) fish is consumed

Question 16

What is Spinucula?

Answer 16

Peanut worm

Question 17

What is chaetognatha?

Answer 17

arrow worms

Question 18

What are characteristics of chaetognatha?

Answer 18

No retractable anterior
* Caudal fin
* Ciliary fans
* Grasping spines (mouth)

Question 19

What are the characteristics of Spiuncula?

Answer 19

Retractable anterior
* Introvert with tentacles – protrusible organ for
feeding
* Live in sediment, among rocks (benthic)
* Brain, central nerve cord with branches

Question 20

How many plathyelminetes are there?

Answer 20

12,000 species

Question 21

How many species of nemertea?

Answer 21

1,000 + species

Question 22

How many species are in nematoda?

Answer 22

12,000 species

Question 23

How many chaetognatha are there?

Answer 23

120 species

Question 24

How many species are in sipuluca?

Answer 24

300

Question 25

What are annelids?

Answer 25

segmented worms

Question 26

What are the characteristics of annelida?

Answer 26

Metamerism (**segmented**) * **Coelom** – fluid **filled body cavity** * **Locomotion** via **longitudinal **and **circular muscles**

Question 27

What is metamerism?

Answer 27

* Repeating digestive glands, reproduction organs, locomotory appendages (serial homology) * Localized **contraction** for **movement**

Question 28

What is the Prostomium of a head segment?

Answer 28

(**front **of mouth) – head

Question 29

What is Peristomium?

Answer 29

(**surrounds** mouth) – 1st “segment

Question 30

What is a Pygidium

Answer 30

the **terminal** part or hind segment of the body

Question 31

What is a coelom?

Answer 31

body cavity** between** the **intestinal** canal and the **body** wall.

Question 32

What is a pseudocoelom?

Answer 32

the body cavity filled with fluid.

Question 33

What are polychaeta?

Answer 33

sandworms, tube worms, clam worms

Question 34

What are mobile and sedentary annelids?

Answer 34

**Err**antia (mobile/swimming) **Sed**entaria (tube dwelling)

Question 35

What are Clitellata

Answer 35

earth worms

Question 36

What are the subclass of earthworms and leeches?

Answer 36

* Subclass: **Oli**gochaeta – earthworms * Subclass: **Hir**udinoidea - leeches

Question 37

What are the types of sedentary feeders?

Answer 37

Suspension feeders Filter Feeders Deposit Feeders

Question 38

How does the feather worm filter feed?

Answer 38

● **Cilia** on the tentacles **direct** small** food** particles ● Small plankton swept into tubes ● If tentacles are disturbed, they will move into tube

Question 39

how does the lungworm deposit feed?

Answer 39

● thin-walled, jawless **proboscis** o used to draw sand into the gut o where organic matter is removed ● It continually eats the sand to create a burrow. ● This draws water into the burrow ● Filters particles from the current

Question 40

What are characteristics of earthworms?

Answer 40

Clitellum – “collar” that forms a reproductive cocoon during part of life cycle. * Located near “head” * ~8,000 species * Hermaphrodites

Question 41

What are the characteristics of leeches

Answer 41

Parasitic * Anterior circumoral sucker * Posterior ventral sucker * ~100 marine species

Question 42

What type of circulatory system do annelids have?

Answer 42

closed circulatory system

Question 43

What are the 2 major blood vessels of annelids

Answer 43

dorsal and ventral: Connected by capillaries which run through all parts of the body

Question 44

How many "hearts" do annelids have and how do they function?

Answer 44

5: In the head region – Connect the ventral and dorsal blood vessels – Rhythmically contract

Question 45

How do annelids reproduce asexually?

Answer 45

- can regenderate - transverse fission: posterior half attaches itself to substrate while anterior half continues to move forward until two halves pull apart

Question 46

Polychaeta Sexual Reproduction

Answer 46

Most male or female (dioecious) * No specific reproductive organs, * **Conversion** of several **posterior segments** into specialized **reproductive** segments * Swim to surface to release gametes * External fertilization

Question 47

What is epitoky?

Answer 47

sexually immature worm is modified or transformed into a sexually mature worm

Question 48

How do earthworms produce sexually?

Answer 48

Hermaphroditic * **Citellum** secrete **cocoon** * **Clitellums** lined up with** game**t-producing sexual **organs** * **External** feralization * No larva stage

Question 49

How do leeches reproduce sexually?

Answer 49

Hermaphroditic * Sperm fertilizes egg still in body * Internal feralization * No larva stage