Bio 1011 Chapter 32

Question 1

Dorsal

Answer 1

Pertaining to the top of an animal with radial or bilateral symmetry

Question 2

Determinate cleavage

Answer 2

future differentiation pathways are determined at an early developmental stage resulting in specialization.

Question 3

Coelomate

Answer 3

the body cavity of higher metazoans, between the body wall and intestine, lined with a mesodermal epithelium.

Question 4

Radial symmetry

Answer 4

When an object has many lines of symmetry that all go through a central point.

Question 5

Bilateral Symmetry

Answer 5

When there is just one line that divides it into halves that are mirror images.

Question 6

Indeterminate cleavage

Answer 6

A type of embryonic development in deuterostomes, in which each cell produced by early cleavage divisions retains the capacity to develop into a complete embryo.

Question 7

deuterostome development

Answer 7

In animals, a developmental mode distinguished by the development of the anus from the blastopore; often also characterized by radial cleavage and by the body cavity forming as outpockets of mesodermal tissue.

Question 8

bilateral symmetry

Answer 8

Characterizing a body form with a central longitudinal plane that divides the body into two equal but opposite halves.

Question 9

triploblastic

Answer 9

Possessing three germ layers: the endoderm, mesoderm, and ectoderm. Most eumetazoa are triploblastic.

Question 10

blastula

Answer 10

The hollow ball of cells marking the end stage of cleavage during early embryonic development.

Question 11

body plan

Answer 11

A particular set of morphological and developmental traits, integrated into a functional whole- the living animal.

Question 12

ventral

Answer 12

Pertaining to the underside, or bottom, of a bilaterally symmetrical animal.

Question 13

ectoderm

Answer 13

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

Question 14

coelom

Answer 14

A body cavity completely lined with mesoderm.

Question 15

protostome development

Answer 15

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

Question 16

archenteron

Answer 16

The endoderm-lined cavity, formed during the gastrulation process, that develops into the digestive tract of an animal.

Question 17

tissues

Answer 17

Groups of cells that have a common structure, function, or both.

Question 18

gastrula

Answer 18

The two-layered, cup-shaped embryonic stage.

Question 19

body cavity

Answer 19

A fluid-containing space between the digestive tract and the body wall.

Question 20

spiral cleavage

Answer 20

A type of embryonic development in protostomes, in which the planes of cell division that transform the zygote into a ball of cells occur obliquely to the polar axis, resulting in cells of each tier sitting in the grooves between cells of adjacent tiers.

Question 21

blastopore

Answer 21

The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes.

Question 22

pseudocoelomates

Answer 22

An animal whose body cavity is lined by tissue derived from mesoderm and endoderm.

Question 23

radial cleavage

Answer 23

A type of embryonic development in deuterostomes in that the planes of cell division that transform the zygote into a ball of cells are either parallel or perpendicular to the polar axis, thereby aligning tiers of cells one above the other.

Question 24

anterior

Answer 24

Referring to the head end of a bilaterally symmetrical animal.

Question 25

acoelomate

Answer 25

A solid-bodied animal lacking a cavity between the gut and outer body wall.

Question 26

larva

Answer 26

A free-living, sexually immature form in some animal life cycles that may differ from the adult in morphology, nutrition, and habitat.

Question 27

metamorphosis

Answer 27

The resurgence of development in an animal larva that transforms it into a sexually mature adult.

Question 28

gastrulation

Answer 28

The formation of a gastrula from a blastula.

Question 29

endoderm

Answer 29

The innermost of the three 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 30

cleavage

Answer 30

The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane; specifically, the succession of rapid cell divisions without growth during early embryonic development that converts the zygote into a ball of cells.

Question 31

mesoderm

Answer 31

The middle primary germ layer of an early embryo that develops into the notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most of the circulatory system.

Question 32

diploblastic

Answer 32

Having two germ layers.