2. Animal Diversity

Question 1

Diplontic life cycle

Answer 1

refers to the life cycle of organisms which is dominated by the diploid stage

Question 2

asymmetry

Answer 2

the lack or absences of symmetry

Question 3

radial symmetry

Answer 3

symmetry in which the body is shaped like a pie or barrel (lacking a left side & right side) and can be divided into mirror imaged halves

Question 4

oral-aboral axis

Answer 4

the establishment. maintenance and elaboration of a line that delineates the mouth and the anus of an embryo

Question 5

bilateral symmetry

Answer 5

body symmetry in which a central longitudinal plane divides the body into two equal but opposite halves

Question 6

cephalization

Answer 6

an evolutionary trend toward the

[ ] of sensory equipment at the anterior end of the body

Question 7

anterior

Answer 7

the front/head of a bilaterally symmetrical animal

Question 8

posterior axis

Answer 8

the rear/tail end of a bilaterally symmetrical animal

Question 9

dorsal axis

Answer 9

the top of an animal with radial or bilateral symmetry

Question 10

ventral axis

Answer 10

the underside/bottom of an animal with radial or bilateral symmetry

Question 11

diploblastic

Answer 11

having 2 germ layers

Question 12

triploblastic

Answer 12

having 3 germ layers

1. the endoderm
2. mesoderm
3. ectoderm

Question 13

endoderm

Answer 13

the innermost of the 3 primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs and the lining of the digestive tract

Question 14

mesoderm

Answer 14

the middle primary germ layer in a triploblastic animal embryo; develops into the notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most circulatory system

Question 15

ectoderm

Answer 15

the outermost of the 3 primary germ layers in animal embryos; gives rise to the outer covering and in so phyla the nervous system, inner ear and lens of the eye

Question 16

coelom

Answer 16

a body cavity lined by tissue derived only from mesoderm

Question 17

protostome

Answer 17

a developmental mode distinguished by the development of the mouth from the blastopore; often characterized by spiral cleavage and by the body cavity forming when solid masses of mesoderm split

Question 18

spiral cleavage

Answer 18

a type of embryonic development in protostomes where the planes of cell division that transform the zygote into a ball of cells are diagonal to the vertical axis of the embryo

Question 19

Deuterostome

Answer 19

in animals a developmental node distinguished by the development of the anus from the blastopore;

Question 20

radial cleavage

Answer 20

a type of embryonic development in deuterostomes where the planes of cell division that transform the zygote into a ball of cells are either parallel/perpendicular to the vertical axis of the embryo

Question 21

invertebrates

Answer 21

an animals without a backbone

Question 22

vertebrates

Answer 22

animal with a backbone

Question 23

mesohyl

Answer 23

a gelatinous region between the two layers of cells of a sponge

Question 24

totipotent

Answer 24

describing a cell that can give rise to all parts of the embryo and adult as well as extra-embryonic membranes in species that have them

Question 25

pluripotent

Answer 25

describing a cell that can give rise to many but not all parts of an organism

Question 26

gastrovascular cavity

Answer 26

a central cavity with a single opening in the body of certain animals (cnidarians, flatowrms) that functions in both the digestion and distribution of nutrients

Question 27

epidermis

Answer 27

the outermost layer of cells in an animal

Question 28

polyp

Answer 28

the sessile variant of the cnidarian body plan; the alternate form is the medusa

Question 29

medusa

Answer 29

the floating, flattened, mouth-down version of the cnidarian body plan; alternate form is the polyp

Question 30

cnidocyte

Answer 30

a specialized cell unique to the phylum Cnidaria; contains a capsule-like organelle housing a coiled threat that when discharged explodes outward and functions in prey capture/defence

Question 31

blastopore

Answer 31

in the gastrula, the opening of the archenteron that typically develops into anus = deuterostomes; mouth=protostomes

Question 32

water vascular system

Answer 32

a network of hydraulic canals unique to echinoderms that branches into extensions called tube feet which function in locomotion and feeding

Question 33

notochord

Answer 33

a longitudinal, flexible rod made of tightly packed mesodermal cells that runs along the anterior-posterior axis of a chordate in the dorsal part of the body

Question 34

mammary gland

Answer 34

an exocrine gland that secretes milk to nourish the young; and is a characteristic of mammals

Question 35

trochophore

Answer 35

distinctive larval stage observed in some lophotrochozoan animals

Question 36

visceral mass

Answer 36

one of three main part of a mollusc containing most of the internal organs

Question 37

mantle

Answer 37

one of the three main parts of a mollusc; a fold of tissue that drapes over the mollusc’s visceral mass and may secrete a shell

Question 38

mantle cavity

Answer 38

a water filled chamber that houses gills, anus and excretory pores of a mollusc

Question 39

radula

Answer 39

a strap-like scraping organ used by many molluscs during feeding

Question 40

cuticle

Answer 40

the exoskeleton of an arthropod, consisting of layers of protein and chitin that are variously modified for different functions

Question 41

exoskeleton

Answer 41

a hard encasement on the surface of an animal (i.e shell of a mollusc, cuticle of an arthropod) that provides protection and points of attachment for muscles

Question 42

moulting

Answer 42

a process in ecdysozoans in which the exoskeleton i shed at intervals, allowing growth by the production of a larger exoskeleton

Question 43

chelicera

Answer 43

one of pair of clawlike feeding appendages character of chelicerates

Question 44

complete metamorphisis

Answer 44

the transformation of a larva into an adult that looks very different and often functions very differently in its environment than the larva

Question 45

incomplete metamorphisis

Answer 45

a type of development in certain insects (grasshoppers) in which the young resemble adults but are smaller and have different body proportions and go through a series of moults; each time looking more like an adult until it reaches full size