Bilateral Invertebrates

Question 1

This group includes phyla with diverse body plans such as flatworms, moluscs, and segmented worms

Answer 1

Lophotrochozoa

Question 2

-Flatworms that have bilateral symmetry and a central nervous system
-They do not have a body cavity or circulatory organs
-Tapeworms, planarians, and flukes belong to this phylum

Answer 2

Platyhelminthes

Question 3

Includes two former phyla
- Rotifers
- Acanthocephalans

Answer 3

Syndermata

Question 4

• Part of the Phylum Synderata
• Microscopic and have complex organ systems

Answer 4

Rotifers

Question 5

• Part of the Phylum Synderata
• Highly modified parasites of vertebrates

Answer 5

Acanthocephalans

Question 6

• (Bryozoans) live as sessile colonies covered by a tough exoskeleton

Answer 6

Ectoprocta

Question 7

• (Lamp shells) superficially resemble clams and other molluscs
• Most have a unique stalk anchoring them to the substrate, and a crown of cilia called a lophophore

Answer 7

Brachiopoda

Question 8

• (Hairy bellies) are tiny worms that have cilia covering their ventral surface
• Most species live at the bottoms of lakes or oceans

Answer 8

Gastrotricha

Question 9

• Symbion pandora, the only known species in this phylum lives on the bodies of lobsters
• Males impregnate females that are still developing within their mother’s bodies

Answer 9

Cycliophora

Question 10

• (Ribbon worms) swim or burrow in sand
• They have a unique proboscis for capturing prey, an alimentary canal, and a closed circulatory system
• The coelom is reduced and the body is solid

Answer 10

Nemertea

Question 11

• Most of these segmented worms live in marine or freshwater habitats
• The most familiar group, earthworms, live in soil

Answer 11

Annelida

Question 12

-Have a soft body, protected by a hard shell in many species
-This phylum includes snails, clams, squids, and octopuses

Answer 12

Mollusca

Question 13

The phyla in this group include more species than all other eukaryotic groups combined

Answer 13

Ecdysozoa

Question 14

-Tiny and live in marine sediments
-The lorica, a pocket formed by six plates, surrounds the abdomen
-The head, neck, and thorax telescope in and out of the lorica

Answer 14

Loricifera

Question 15

• These worms have a large, rounded proboscis at their anterior end
• They range from 0.5 mm to 20 cm in length
• Most species burrow in seafloor sediments
• Priapulans were major predators during the Cambrian period

Answer 15

Priapula

Question 16

• (Velvet worms) originated during the Cambrian explosion
  Originally marine, today they live in humid forests
• They have fleshy antennae and several dozen pairs of saclike legs

Answer 16

Onychophora

Question 17

• (Roundworms) are abundant in soil and aquatic habitats
• Many species parasitize plants and animals
• A tough cuticle coats their body

Answer 17

Nematoda

Question 17

• (Water bears) have a bearlike shape and gait, though most are less than 0.5 m m long
• They live in aquatic habitats, or on plants or animals
• In the dormant state, they can survive for days at temperatures as low as -200 C

Answer 17

Tardigrada

Question 18

• The majority of known animal species, including insects, crustaceans, and arachnids, are arthropods
• All have a segmented exoskeleton with jointed appendages

Answer 18

Arthropoda

Question 19

This group includes both invertebrate and vertebrate species

Answer 19

Deuterstomia

Question 20

• Share some traits with chordates, such as gill slits and a dorsal nerve cord
• The largest group is the acorn worms, marine animals that live in mud or under rocks
• They can grow to more than 2 m in length

Answer 20

Hemichordata

Question 21

• More than 90% are vertebrates
• There are also two groups of invertebrates: lancelets and tunicates

Answer 21

Chordata

Question 22

• Marine animals that are bilaterally symmetrical as larvae, but not as adults
• They move and feed by pumping water through a network of internal canals
• Sand dollars, sea stars, and sea urchins are echinoderms

Answer 22

Echinodermata