Chapter 33

Question 1

What percent of animals are invertebrates?

Answer 1

95%

Question 2

Porifera

Answer 2

Phylum with mostly sponges. They are sessile animals that lack true tissues they live as filter feeders

Question 3

Cnidarians

Answer 3

Include corals jellies and hydras. They have a diploblastic radially symmetrical body plan that includes a gastrovascular cavity with a single opening that serves as both mouth and anus

Question 4

Acoela

Answer 4

Flatworms that have a simple nervous system and a saclike gut. It is a separate lineage that diverged before the three main bilaterian clades

Question 5

Placozoa

Answer 5

One species that doesn’t even look like an animal. Consists of a simple bilayer of a few thousand cells thought to be basil animals but it is not yet known how they are related to other early diverging animal groups. Reproduce by dividing into two individuals or by budding off of mini multicellular individuals.

Question 6

Ctenophora

Answer 6

Comb jellies that are diploblastic and radially symmetrical like cnidarians. This suggests that both Philo diverged from other animals very early. Comb jellies make up much of the ocean is plankton. They have eight combs of cilia the pro pal the animals through the water

Question 7

Platyhelminthes

Answer 7

Flatworms including tapeworms planarians and flukes which of bilateral symmetry and a CNS that processes information from sensory structures. These have nobody cavities or specialized organs for circulation. Part of locotrophozoa

Question 8

Ectoprocta

Answer 8

Bryozoans, Live as sessile colonies and are covered by a tough XO skeleton. Part of locotrophozoa

Question 9

Rotifera

Answer 9

Have specialized organ systems including an ailmentary canal(A digestive tract with both a mouth and an anus). They feed on microorganisms suspended in water. Part of locotrophozoa

Question 10

Brachiopoda

Answer 10

Lampshells may be easily mistaken for clams or other mollusks however most brachiopods, have a unique stock that anchors them to their substrate as well as a crown of cilia called a lophophore. Part of locotrophozoa

Question 11

Acanthocephala

Answer 11

Spiny headed worms because of the curved hooks on the probiscs at the interior end of their body. All species are parasites. Part of locotrophozoa

Question 12

Cycliophora

Answer 12

Tiny vase shaped creature has a unique body plan in a particularly bizarre lifecycle. Males impregnate females that are still developing in their mothers bodies. Fertilize females that escaped settle elsewhere on the lobster and release their offspring the offspring apparently leave that lobster and search for another one which they attach. Part of locotrophozoa

Question 13

Nemertea

Answer 13

Also called probiscis worms or ribbon worms. They swim through the water or borrow and sand extending a unique probiscis to capture prey. Like flatworms they lack a true Coelom. Part of locotrophozoa

Question 14

Annelida

Answer 14

Segmented worms. Distinguished from other worms by their body segmentation. Earthworms are the most familiar annelids but the phylum consist primarily of marine and freshwater species. Part of locotrophozoa

Question 15

Mollusca

Answer 15

Snails clams squids and octopuses. Have a soft body that many species is protected by a hard shell. Part of locotrophozoa

Question 16

Loricifera

Answer 16

Tiny animals that inhabit sediments on the seafloor. Can telescope its head neck and thorax in and out of the Lorica, A pocket formed by six plates surrounding the abdomen. Part of the group ecdysozoa

Question 17

Priapula

Answer 17

Worms with a large rounded probiscis at the anterior end. Most species borough through the seafloor sediments. Fossils evidence suggests that priapulans where are among the major predators during the Cambrian period. Part of the ecdysozoa group

Question 18

Onychophora

Answer 18

Also called velvet worms originated during the Cambrian explosion. Originally they thrived in the ocean but at some point they succeeded into colonizing Land. Today they only live in humid forests. Part of ecdysozoa

Question 19

Tardigrada

Answer 19

Water bears. Rounded shape stubby appendages and lumbering. Some live in oceans or freshwater well others live on plants or animals as many as 2 million tardigrade’s can be found on a square meter of moss. Harsh conditions may cause tardigrade’s to enter a state of dormancy while dormant they can survive for days at temperatures as low as -200°C. Part of ecdysozoa

Question 20

Nematoda

Answer 20

Also called roundworms nematodes are very abundant and diverse in the soil and an aquatic habitats many species parasitize plants and animals. You’re most distinctive feature is a tough cuticle that coats the body. Part of ecdysozoa

Question 21

Anthropoda

Answer 21

Vast majority of known animal species including insects crustaceans and arachnids are anthropoids. They all have segmented XO skeleton and jointed appendages. Part of ecdysozoa.

Question 22

Hemichordata

Answer 22

Members of the deuterostome clade. Share some trades with chordates such as gill slits and dorsal nerve cord. Enteropneusts are the largest group of hemichordates. Part of dueterostomia

Question 23

Chordata

Answer 23

More than 90% of all known cordate species have backbones however the phylum Chordata also includes three groups of invertebrates; Lancelets tunicates and hagfishes. Part of dueterostomia

Question 24

Echinodermata

Answer 24

Such as Sandollar’s sea stars and see urchins are marine animals in the deuterostome clade that are bilaterally symmetrical as larvae but not as adults. They move and feed by using a network of internal canals to pump water to different parts of their body. Part of dueterostomia.