Invertebrates

Question 1

How many roundworms are there thought to be?

Answer 1

1 million but 25000 known

Question 2

What are the features of roundworms?

Answer 2

Bilateral symmetry

Cylindrical body with tapered end

Question 3

Are internal organs in round worm surrounded by mesoderm?

Answer 3

No so they are psedocoelomate

Question 4

What is the purpose of multi layered cuticle?

Answer 4

Helps maintain high pressure

Question 5

Are the muscles in the round worm antagonistic?

Answer 5

No

Question 6

How do muscles in the round worm work?

Answer 6

They twitch side to side and the hydrostatic skeleton pills them into shape

Question 7

What is the scientific name for round work?

Answer 7

Nematoda

Question 8

What is the lifestyle like for free living round worm?

Answer 8

Marine freshwater terrestrial
All habitats dessert to polar region
Feed on bacteria
Microscopic organisms

Question 9

What is an important of free living round worms in the soil?

Answer 9

Important in soil nutrient cycling

Question 10

What are the two lifestyles of roundworms?

Answer 10

Free living

Parasites of animals

Question 11

What is elephantiasis caused by?

Answer 11

Infection with filariasis type nematodes which infects lymphatic system

Question 12

How do roundworm reproduce?

Answer 12

Sexual reproduction- internal fertilisation

Question 13

Are roundworm mainly dioecious (mainly male or female)?

Answer 13

Yes

Question 14

What was the first multicellular organisms to have its genome sequenced?

Answer 14

Caenorhabditis elegans

Question 15

What are examples of the phylum Echinodermata?

Answer 15

Sea lilies
Sea urchins
Star fish
Sea cucumbers

Question 16

What are features of Echinodermata?

Answer 16

All marine, bilateral symmetry in larvae but 5 fold radial symmetry in adults, coelomates

Question 17

What is the body plan of Echinodermata?

Answer 17

Water vascular system and thin epidermis covering a endoskeleton and external spines

Question 18

How to Echinodermata reproduce?

Answer 18

Sexual reproduction with separate sexes

Question 19

How many species are Echinodermata?

Answer 19

7000

Question 20

What are the features of the phylum Mollusca?

Answer 20

Eg snails, clams, octopuses
Bilateral symmetry
Muscular foot
Well developed head

Question 21

What are features of the class Bivalvia?

Answer 21

Aquatic animals with two shell valves
Sedentary or burrowing
Expanded gills for filter feeding
Separate sexes

Question 22

What is torsion?

Answer 22

Twisting of the body in relation to head and foot brings anus above the head

Question 23

What is a Ctenidia?

Answer 23

Gill

Question 24

What are features of the class Gastropoda?

Answer 24

Well developed head
Assymmetrical body
Herbivorous or carnivorous
Separate sexes or hermaphrodite

Question 25

Do snails have both both genitalia?

Answer 25

Yes

Question 26

How do snails mate?

Answer 26

Slow ritual where sperm and a love dart (mucus covered calcareous dart) is exchanged

Question 27

Are love darts a secondary sexual characteristic?

Answer 27

Yes

Question 28

What are features of the class Cephalopoda?

Answer 28

``` Marine predator Interanal shell Eg squid Brain in braincase Courtship between separate sexes ```

Question 29

What are features of the phylum Annelida?

Answer 29

Eg fan worms, earthworm Bilateral symmetry Body covered in chaetae (bristles used for movement)

Question 30

What are advantages of coelomate body plan?

Answer 30

Hydrostatic skeleton | Transport of excretory and sexual products

Question 31

What are advantages of Metameric segmentation?

Answer 31

Allow independent movement of different of muscles

Question 32

What are advantages of a body covered with chaetae?

Answer 32

Bristles help with movement

Question 33

What are features of errantia?

Answer 33

On sea floor Well defined jaw and eyes Body segment with prominent parapodia sexual reproduction

Question 34

What are features of sedentaria?

Answer 34

Earthworms are burrowers Leeches are ectoparasites or predators Hermaphrodites Regeneration