Chapter 32: An Overview Of Animal Diversity

Question 1

Tissues

Answer 1

An integrated group of cells with a common structure, function, or both

Question 2

Cleavage

Answer 2

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

Question 3

Blastula

Answer 3

A hollow ball of cells that marks the end of the cleavage stage during early embryonic development in animals

Question 4

Gastrulation

Answer 4

In animal development, a series of cell and tissue movement in which the blastula-stage embryo folds inwards, producing a three-layered embryo, the gastrula

Question 5

Gastrula

Answer 5

An embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm, and endoderm

Question 6

Larva

Answer 6

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

Question 7

Metamorphosis

Answer 7

A developmental transformation that turns an animal larva into either an adult or an adult-like stage that is not yet sexually mature

Question 8

Ediacaran Biota

Answer 8

An early group of macroscopic, mostly soft-bodied, multicellular eukaryotes from fossils that range in age from 635 million to 541 million years old.

Question 9

Cambrian Explosion

Answer 9

A relatively brief time in geologic history when many present day phyla of animals first appeared in the fossil record. This burst of evolutionary change occurred about 535-525 million years ago and saw the emergence of the first large, hard bodied animals

Question 10

Bilaterian

Answer 10

A member of a clade of animals with bilateral symmetry and three germ layers

Question 11

Body plan

Answer 11

In multicellular eukaryotes, a set of morphological and developmental traits that are integrated into a functional whole, the living organism

Question 12

Ectoderm

Answer 12

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

Question 13

Endoderm

Answer 13

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 in species that have these structures

Question 14

Diploblastic

Answer 14

Having two germ layers

Question 15

Mesoderm

Answer 15

The middle primary layer in a triploblastic animal embryo; develops into the notochord, the lining of the coelom, muscles, kidneys, gonads, the skeleton and most of the circulatory system in species that have these structures

Question 16

Triploblastic

Answer 16

Possessing three germ layers: the endoderm, mesoderm, and ectoderm. All bilaterian animals are triploblastic

Question 17

Body Cavity

Answer 17

A fluid or air filled space between the digestive tract and the body wall

Question 18

Coelom

Answer 18

A body cavity lined by tissue derived only from the mesoderm

Question 19

Hemocoel

Answer 19

A body cavity lined by tissue derived from mesoderm and by tissue derived from endoderm

Question 20

Protostome Development

Answer 20

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

Question 21

Deuterostome development

Answer 21

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 22

Spiral Cleavage

Answer 22

A type of embryonic development in protostomes in which the planes of cell division that transform that zygote into a ball of cells are diagonal to the vertical axis of the embryo. As a result, the cells of each tier sit i the groves between cells of adjacent tiers.

Question 23

Determinate Cleavage

Answer 23

A type of embryonic development in protostomes that rigidly casts the developmental fate of each embryonic cell very early

Question 24

Radial Cleavage

Answer 24

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

Question 25

Indeterminate cleavage

Answer 25

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

Question 26

Archenteron

Answer 26

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

Question 27

Blastopore

Answer 27

In a gastrula, the opening of the archenteron that typically develops into the anus in Deuterostomes and the mouth in protostomes

Question 28

Deuterostomia

Answer 28

One of the three main lineages of bilaterian animals

Question 29

Lophotrochozoa

Answer 29

One of the three main lineages of bilaterian animals; includes organisms that have lophophores or trochohore larvae

Question 30

Lophophore

Answer 30

In some lophotrochozoan animals, including branchipods, a crown of ciliated tentacles that surrounds the mouth and functions in feeding

Question 31

Trochophore Larva

Answer 31

Distinctive larval stage observed in some lophotrochozoan animals, including some annelids and mollusks

Question 32

Ecdysozoa

Answer 32

One of the three main lineages of bilaterian animals; Many are molting animals