Chapter 33

Question 1

gastrulation

Answer 1

the process by which some cells on the outside of an embryo move to the interior of the embryo, resulting in the three distinct germ layers

Question 2

corona

Answer 2

Any crown-like appendage of a plant or animal

Question 3

direct development

Answer 3

The newborn is born or emerges from its egg as a miniature version of the adult. It looks like the adults of its species, and it also feeds like an adult of its species.

Question 4

definitive host

Answer 4

a host in which the parasite reaches maturity and, if possible, reproduces sexually.

Question 5

intermediate host

Answer 5

an organism that supports the immature or nonreproductive forms of a parasite.

Question 6

Clitellata

Answer 6

thickened glandular and non-segmented section of the body wall near the head in earthworms and leeches, that secretes a viscid sac in which the eggs are deposited.

Question 7

Chaetae

Answer 7

A bristle, made of chitin, occurring in annelid worms. In the earthworm they occur in small groups projecting from the skin in each segment and function in locomotion.

Question 8

parapodia

Answer 8

paired, lateral appendages extending from the body segments.

Question 9

veliger

Answer 9

characteristic larva of the gastropod, bivalve and scaphopod taxonomic classes

Question 10

radula

Answer 10

anatomical structure that is used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus.

Question 11

spermatophore

Answer 11

a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female’s ovipore during reproduction.

Question 12

coelom

Answer 12

an internal usually fluid filled body cavity that is lined with mesoderm

Question 13

chelicera

Answer 13

The first pair of appendages on the head of arachnids and other arthropods of the phylum Chelicerata. These appendages take the form of pincers or claws and are used for grasping or tearing food.

Question 14

visceral mass

Answer 14

one of the three main parts of the mollusk body; contains most of the internal organs and the external gills

Question 15

cuticle

Answer 15

a protective coating secreted by the outermost layer of cells an animal or plant

Question 16

exoskeleton

Answer 16

a hard covering secreted on the outside of the body, used for body support, protection, and muscle attachment Example-shell of mollusk

Question 17

molting

Answer 17

a method of body growth, used by ecdyszoans, that involves the shedding of an external protective cuticle or skeleton, expansion of the soft body, and growth of a new external layer

Question 18

triploblastic

Answer 18

an animal whose body develops from three basic embryonic germ layers (endoderm, mesoderm, ectoderm)

Question 19

compound eye

Answer 19

The quality of vision of these eyes is lower in resolution than that of vertebrates, but compound eyes can pick up the smallest movements that others miss. made up of many repeating units called ommatidia.

Question 20

simple eye

Answer 20

a basic type of eye consisting of a collection of cells that are sensitive to light, or having only one lens, as found in some insects. a small eye of an insect or other arthropod which has only one lens, typically present in one or more pairs

Question 21

chelicera

Answer 21

The first pair of appendages on the head of arachnids and other arthropods of the phylum Chelicerata. These appendages take the form of pincers or claws and are used for grasping or tearing food.

Question 22

carapace

Answer 22

a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises.

Question 23

mandible

Answer 23

The lower jaw of a vertebrate animal. 2. Either the upper or lower part of the beak in birds. 3. Any of various mouth organs of invertebrates used for seizing and biting food, especially either of a pair of such organs in insects and other arthropods.

Question 24

nauplius

Answer 24

in many crustaceans a larval form with three pairs of appendages and a single median eye, occurring usually as the first stage of development after leaving the egg. The young barnacle in no way resembles the adult.

Question 25

hydrostatic skeleton

Answer 25

a system of body support involving fluid filled compartments that can change in shape but cannot easily be compressed

Question 26

thorax

Answer 26

a region of the body in insects; one of the three prominent body regions called tagmata

Question 27

tagmata

Answer 27

three regions of the insect: head thorax abdomen

Question 28

chitin

Answer 28

a structural polysaccharide composed of N-acetylglucosamine monomers joined end to end by B-1, 4-glycosidic lineages. Found in cell walls of fungus and algae and in external skeletons of insects and crustaceans

Question 29

hemocoel

Answer 29

a body cavity, present in arthropods and some mollusks, containing a pool of circulatory fluid(hemolymph) bathing the internal organs

Question 30

mantle

Answer 30

one of the three main parts of the mollusk body; the thick outer tissue that protects the visceral mass and may secrete a calcium carbonate shell

Question 31

proboscis

Answer 31

a long narrow feeding appendage through which food can be obtained

Question 32

siphon

Answer 32

a tubelike appendage of many mollusks that is often used for feeding or propulsion

Question 33

parthenogenesis

Answer 33

development of offspring from unfertilized eggs; a type of asexual reproduction

Question 34

lophotrochozoans

Answer 34

a major lineage of protostomes that grow by extending the size of their skeletons rather than molting