Exam 2 Vocab 2

Question 1

Benthic

Answer 1

Living at the bottom of aquatic environments

Question 2

Sessile

Answer 2

Permanently attached substrate

Question 3

Diploblasts

Answer 3

Animals whose embryos have two germ layers (ecto and endoderm)

Question 4

Triploblasts

Answer 4

Animals whose embryos have 3 germ layers (end, ectoderm and mesoderm)

Question 5

Chephalization

Answer 5

Evolution of a head where structures for feeding, sensing the environment and processing info are concentrated

Question 6

Coelom

Answer 6

enclosed fliud-filled body cavity between the tubes

Question 7

Segmentation

Answer 7

presence of repeated body structures

Question 8

Visceral mass

Answer 8

One of the 3 main parts of the mollusk body; contains most of the internal organs and external gills

Question 9

trochophore

Answer 9

a larva with a ring of cilia around its middle that is found in some lopotrochozoans

Question 10

Worm

Answer 10

an animal with a long, thin, tubelike body lacking limbs

Question 11

Roundworms

Answer 11

members of the nematoda. Distinguished by an unsegmented body with a pseudocoelom and no appendages. Ecdysozoan

Question 12

Rotifer

Answer 12

Rotifera. Distinguished by a cluster of cilia,called corona, used in suspension feeding in marine and freshwater environments. lophotrochozoan

Question 13

Molting

Answer 13

Method of body growth by ecdysozons, that involves the shedding of an external protective cuticle or skeleton, expansion of the soft body, and growth of a new external layer.

Question 14

Lophophore

Answer 14

a specialized feeding structure found in some lophotrochozoans and used in suspension (filter) feeding

Question 15

Flatworms

Answer 15

members of the phylum Playhelminthes. Distinguished by a broad, flat, unsegmented body that lacks a coelom. Flatworms belong to the lophotrochozoan branch of protostomes.

Question 16

Arthropods

Answer 16

members of phylum Arthropoda. Distinguished by a segmented body; a hard, jointed exoskeleton; paired, jointed appendages; and an extensive body cavity called a hemocoel. Arthropods belong to the ecdysozoan branch of the protostomes

Question 17

Annelids

Answer 17

members of the phylum Annelia (segmented worms). Distinguished by a segmented body and a coelom that functions as a hydrostatic skeleton. Annelids belong to the lophotrochozoan branch of the protostomes

Question 18

Bilateral symmetry

Answer 18

an animal body pattern in which one plane of symmetry divides the body into a left side and a right side. Typically, the body is a long and narrow, with a distinct head end and tail end.

Question 19

Brain

Answer 19

a large mass of neurons, located in the head region of an animal, that is involved in information processing; may also be called the cerebral ganglion

Question 20

Acoelomate

Answer 20

a bilaterian animal that lacks an internal body cavity (coelom).

Question 21

CNS

Answer 21

large numbers of neurons aggregated into clusters called ganglia in bilaterian animals. In vertebrates, the central nervous system consists of the brain and spinal cord.

Question 22

Choanocyte

Answer 22

a specialized, flagellated feeding cell found in choanoflagellates (protists that are the closest living relatives of animals) and sponges (the most ancient animal phylum)

Question 23

Cnidocyte

Answer 23

a specialized stinging cell found in cnidarians (jellyfish, corals, anemones) and used in capturing prey

Question 24

Coelomate

Answer 24

an animal that has a true coelom, completely lined with mesoderm

Question 25

Colony

Answer 25

an assemblage of individuals

Question 26

Deposit feeder

Answer 26

an animal that eats its way through a food containing substrate

Question 27

Detritivore

Answer 27

an organism whose diet consists mainly of dead organic matter (detritus). Varous bacteria, fungi, protists, and animals are detrivores. Also called decomposer

Question 28

Deuterostomes

Answer 28

major lineage of bilaterian animals that share a pattern of embryological development, including formation of the anus earlier that the mouth, and formation of the coelom by pinching off of layers of mesoderm from the gut. Includes echinoderms and chordates

Question 29

Ectoderm

Answer 29

the outermost of the three basic cell layers in most animal embryos: gives rise to the outer covering and nervous system

Question 30

Endoderm

Answer 30

the innermost of the three basic cell layers (germ layers) in most animal embryos; gives rise to the digestive tract and organs that connect to it