Chapter 23

Question 1

amniotic egg

Answer 1

an egg with a hard outer casing and an inner series of membranes and fluids that provide protection, nutrients, and waste disposal for a growing embryo. The evolution of the amniotic egg, in reptiles, freed them from the constraint of having to reproduce near water

Question 2

bilateral symmetry

Answer 2

a bodily symmetry in which opposite sides of a sagittal plane are mirror images of one another. Animals generally are bilaterally symmetrical

Question 3

body segmentation

Answer 3

a repetition of body parts in an animal. An example can be found in the vertebrae that make up the human vertebral column or backbone

Question 4

Example of body segmentation

Answer 4

vertebrae that make up the human vertebral column or backbone

Question 5

bud

Answer 5

an undeveloped plant shoot, composed mostly of meristematic tissue

Question 6

closed circulation system

Answer 6

a type of circulatory system, found in all vertebrates and in some invertebrates, in which blood stays within vessels

Question 7

coelom

Answer 7

a central body cavity, found in most animal phyla

Question 8

copulation

Answer 8

the release of sperm within a female by a male reproductive organ

Question 9

exoskeleton

Answer 9

an external material covering the animal body, providing support and protection

Question 10

hermaphrodite

Answer 10

a state in which one animal possesses both male and female sex organs

Question 11

hydrostatic skeleton

Answer 11

a skeleton in which the force of muscular contraction is applied through a fluid

Question 12

invertebrate

Answer 12

an animal without a vertebral column

Question 13

molting

Answer 13

a periodic sheding of an old exoskeleton followed by the growth of a new one; practiced by animals in the phyla Nematoda and Arthropoda

Question 14

organ

Answer 14

a highly organized unit within an organism, performing one or more function, that is formed of several kinds of tissue

Question 15

Examples of organs

Answer 15

kidneys, heart, lungs, and liver

Question 16

open circulation

Answer 16

a type of circulation, found in many invertebrates, in which arteries carry blood into open spaces called sinuses. The blood then bathes surrounding tissues and is channeled into veins, through which it flows back to the heart

Question 17

oviparous

Answer 17

a condition, seen in all birds and many reptiles, in which fertilized eggs are laid outside the mother’s body and then develop there

Question 18

parasite

Answer 18

organisms that feed off their prey but do not kill them, at least not immediately and perhaps not ever

Question 19

parthenogenesis

Answer 19

a form of asexual reproduction in which an unfertilized egg develops into an adult organism

Question 20

radial symmetry

Answer 20

a type of animal symmetry in which body parts are distributed evenly about a central axis

Question 21

examples of radially symmetrical animals

Answer 21

jellyfish

Question 22

symmetry

Answer 22

an equivalence of size, shape, and relative position of parts across a dividing line or around a central point

Question 23

tissue

Answer 23

an organized assemblage of similar cells that serves a common function

Question 24

Examples of tissue

Answer 24

nervous, epithelial, and muscle tissue

Question 25

vertebral column

Answer 25

a flexible column of bones extending from the anterior to posterior end of an animal. Also known as a backbone, the vertebral column distinguishes vertebrates from other chordates

Question 26

viviparous

Answer 26

a condition in animals in which fertilized eggs develop inside a mother’s body