Protostomes pt.1

Question 1

All remaining organisms are apart of what group?

Answer 1

Bilateria

Question 2

What are the 4 types of bilateral symmetry?

Answer 2

1. Anterior
2. Posterior
3. Dorsal
4. Ventral

Question 3

What are some characteristics of acoel flatworms?

Answer 3

1. They lack a coelom
2. Lack a permanent digestive system
3. Thought to be related to Platyhelminthes but recent evidence shows that they are not as close as we once though.

Question 4

What are 4 characteristics of lophotrochozoa?

Answer 4

1. They grow by gradually adding body mass
2. Spiral cleavage
3. Many have free-living larva called trochophore.
4. Some have a feeding structure called lophophore.

Question 5

What are two characteristics of Ecdysozoa?

Answer 5

1. Animals that molt
2. Step-wise growth

Question 6

Platyhelminthes include?

Answer 6

Flatworms

Question 7

Mollusca include?

Answer 7

Snails, mussels, octopi, etc.

Question 8

Annelida include?

Answer 8

Segmented worms (earth worms)

Question 9

What are five characteristics of flatworms?

Answer 9

1. Dorsoventrally flattened
2. Incomplete gut, only one opening (Digestive system completely gone in tapeworms)
3. Mouth midventral
4. Acoelomate
5. Most are hermaphroditic

Question 10

What are the three parts of a flatworms body plan?

Answer 10

1. Simple nervous system
2. Complex reproductive system
3. Excretory system

Question 11

What are the 2 groups of flatworms?

Answer 11

1. Free living (Tubellaria-marine, freshwater, and land planarians)
2. Parasitic(Neodermata-flukes and tapeworms)

Question 12

What are five characteristics of Mollusca?

Answer 12

1. Coelomate, coelom reduced
2. Complete gut
3. Microscopic to huge
4. Mostly marine
5. Economically important

Question 13

What are the four parts of a mollusk body plan?

Answer 13

1. Mantel-thick epidermis layer which secretes shell
2. Foot-muscular, used for swimming, digging, modified into tentacles or arms in some
   3.Radula-chitinous teeth form rasping, tongue-like structure, lost in some
3. Shell-secreted by mantle, lost or reduced in some

Question 14

What are the 4 characteristics of Mollusca-Polyplacophora?

Answer 14

1. Marine mollusks with oval bodies
2. 8 overlapping dorsal calcareous plates (shell)
3. Mostly herbivores
4. Muscular foot for attaching to rocks

Question 15

What are five characteristics of Mollusca-Gastropoda?

Answer 15

1. Primarily marine, some freshwater, only terrestrial mollusks
2. Most with single shell, lost or reduced in some
3. Pairs of tentacles with eyes
4. Foot modified for locomotion/crawling
5. Torsion-unique among animals (twisting of viscera during development)

Question 16

What are some characteristics of Mollusca- Bivalvia?

Answer 16

1. Clams, scallops, mussels, oysters, and more
2. Mostly marine, some freshwater
3. Freshwater mussels (Specialized parasitic larva-glochidia)
4. Filter feeders
5. Have two shells (valves) hinged together
6. Laterally compressed
7. Muscular foot for burrowing

Question 17

What are some characteristics of Mollusca-Cephalopoda?

Answer 17

1. Octopuses, squid, nautilus, cuttlefish
2. Strictly marine
3. Active predators
4. Highly developed nervous system(eyes similar to ours developed, separately)
5. Foot highly modified
6. Radula inside beak-like jaws
7. External shell lost in most (present in chambered nautilus, internal in squid and cuttlefish)
8. Chromatophores-change skin color for camouflage and communication
9. Ink sac-ink release as a defense