Ch 30 Animals 1

Question 1

• Eukaryotic
• Multicellular
• all are heterotrophic
– ingest food then digest
• locomotion at some time during life cycle • most have a nervous system and muscles
• multicellular diploid stage and a unicellular haploid stage (gametes)

Answer 1

Animals

Question 2

Have diverse body plans

Answer 2

Animals

Question 3

– basic structure and functional design of body

Answer 3

Body plan

Question 4

Biologists have traditionally used structural characters (variations in body symmetry, number of tissue layers, type of body cavity) and early development patterns to

Answer 4

infer relationships among animal phyla.

Question 5

Sponges are not symmetrical

Answer 5

Asymmetry

Question 6

– many possible sections can divide the body into equal halves
– shared by cnidarians and ctenophores
• example: jellyfish (cnidarian)

Answer 6

Radial Symmetry

Question 7

– only one section divides the body into equal halves
– directional movement
– led to cephalization: development of head

Answer 7

Bilateral Symmetry

Question 8

Separate tissue layers during early development

Answer 8

Germ layers

Question 9

– gives rise to body covering, nervous system

Answer 9

Outer layer (ectoderm)

Question 10

– lines the gut and other digestive organs

Answer 10

Inner layer (endoderm)

Question 11

– gives rise to most other body structures

Answer 11

Middle layer (mesoderm)

Question 12

Not organized into tissues

Answer 12

Sponges

Question 13

Cnidarians and ctenophores have only 2 layers

Answer 13

Diploblastic

Question 14

Other animals have all 3 layers

Answer 14

Triploblastic

Question 15

First opening from embryonic gut to outside

Answer 15

Blastopore

Question 16

Means “first the mouth”

– develops into the mouth

Answer 16

Protostomes

Question 17

means “second the mouth”

– becomes the anus

Answer 17

Deuterostomes

Question 18

– no body cavity

Answer 18

Acoelomate

Question 19

– body cavity not completely lined with mesoderm

Answer 19

Pseudocoelomate

Question 20

– body cavity completely lined with mesoderm

Answer 20

Coelomate, (animal with true coelom)

Question 21

Fossils and comparisons based on molecular evidence suggest that the first animals inhabited

Answer 21

Shallow marine environments

Question 22

Evolutionary modification that improves an organism’s chance of survival and reproduction

Answer 22

Adaptation

Question 23

Members of most major clades of animals still inhabit

Answer 23

Marine environments

Question 24

– relatively stable temperatures
– buoyancy
– readily available food

Answer 24

Marine Environments Provide

Question 25

– more easily maintained than in fresh water or air

Answer 25

Fluid and salt balance

Question 26

- strong swimming, attachment to sea floor | - some small and move with water (plankton)

Answer 26

Marine Environments adaptations

Question 27

– limited water – much less constant conditions – no buoyancy

Answer 27

Terrestrial Animals Challenges

Question 28

– protection from drying out • impermeable coverings, internal respiratory surface, internal fertilization – protect them from temperature changes • insulating coverings, behavior changes – strong support structures (skeletons)

Answer 28

Terrestrial Animals Adaptations