Zoology Final d

Question 1

common mammal characteristics

Answer 1

• mammary glands
• sweat glands
• hair
• 3 middle ear bones
• neocortex in the brain
• diaphragm

Question 2

skin

Answer 2

• hair follicles located in dermis of skin

- as new cells are produced they are carried away from their source of nourishment and die, turning into keratin

Question 3

two kinds of hair

Answer 3

• underhair

- guard hair

Question 4

underhair

Answer 4

• for insulation

- so dense in aquatic mammals that i keeps them from getting wet

Question 5

guard hair

Answer 5

for protection and coloration

Question 6

skin glands

Answer 6

• sebaceous glands that produce sebum

- scent glands used for communication; located on head, penis, anal region, back of head, legs, armpits

Question 7

two types of sweat glands

Answer 7

• eccrine glands

- apocrine glands

Question 8

eccrine glands

Answer 8

for evaporative cooling

Question 9

apocrine glands

Answer 9

• associated with reproductive cycle

- types: mammary gland

Question 10

mammary gland

Answer 10

occur on all female mammals and in rudimentary form on males

Question 11

horns and antlers

Answer 11

• horns have core of bone and are permanent

- antlers develo in spring beneath velvet and are shed each year

Question 12

What animal has been pushed to brink of extinction by demand for its horns?

Answer 12

white rhinoceros from Asia Africa

Question 13

teeth

Answer 13

• sets mammals apart and reveals life habits

- mammals have heterodont (different) dentition, where reptiles have homodont (same) dentition

Question 14

dentition

Answer 14

teeth

Question 15

animals with homodont dentition

Answer 15

american crocodile

Question 16

animals with heterodont dentition

Answer 16

fox

tiger

Question 17

what are different types of teeth in mammals

Answer 17

• incisors
• canines
• premolars
• molars

Question 18

incisors

Answer 18

used to nip, seize food

Question 19

canines

Answer 19

used to kill, stab prey

Question 20

premolars

Answer 20

used for slicing and crushing

Question 21

molars

Answer 21

used for crushing

Question 22

diphyodont dentition

Answer 22

having two sets of teeth:

• temporary set (baby teeth)
• permanent set

Question 23

deciduous teeth are what?

Answer 23

• baby teeth

- milk teeth

Question 24

different feeding types in mammals

Answer 24

• insectivores
• carnivores
• omnivores
• herbivores
• variations have occurred such as filter feeding in whales

Question 25

characteristics of insectivores

Answer 25

- short intestine, no cecum | - little fibrous vegetable matter that requires prolonged fermentation

Question 26

characteristics of nonruminant herbivores

Answer 26

- elephants, rodents, horses rabbits - cecum serves as fermentation chamber harboring microorganisms that can break chemical bonds of cellulose - simple stomach, large cecum

Question 27

characteristics of ruminant herbivores

Answer 27

- cattle, bison, goats, antelopes - four-chambered stomach with large rumen - cud formed in rumen returned to mouth for chewing, then back to rumen - relatively long intestines

Question 28

rumen

Answer 28

chamber to help in digesting cellulose

Question 29

what are the three different types of herbivores?

Answer 29

- nonruminant herbivores - ruminant herbivores - herbivores that exhibit coprophagy

Question 30

herbivores that exhibit coprophagy

Answer 30

- hares, rabbits, some rodents | - eat own feces to give food second pass through cecum

Question 31

characteristics of carnivores

Answer 31

- short intestine and colon, small cecum - no need to feed continuously as herbivores do - get enough our of what we they do eat

Question 32

characteristics of omnivores

Answer 32

- small or no cecum | - relatively long intestine

Question 33

respiration in mammal

Answer 33

possess diaphragm for creating negative pressure to suck air into lungs

Question 34

pinnae

Answer 34

- adaptation of head - external ears - used to catch sound, thermoregulation

Question 35

ears in mammals

Answer 35

- more complex inner ear | - 3 middle ear bones: malleus, incus and stapes

Question 36

hearing in mammals

Answer 36

- very well-developed especially in bats - echolocation enables bats to navigate in total darkness - toothed whale and dolphins use echolocation too

Question 37

earliest synapsids reptiles

Answer 37

- pelycosaurs - neural spines of vertebrae supported large sail-like structure, possibly for thermoregulation - teeth show beginnings of heterdont dentition

Question 38

synapsids

Answer 38

refers to shape of skull, holes in head for attachment of jaw muscles

Question 39

After synapsids, came therapsids....

Answer 39

had efficient erect gait with upright limbs positioned beneath the body

Question 40

after therapsids, came cynodants....

Answer 40

- high metabolic rate - increased jaw musculature - mammal-like, heterodont dentition

Question 41

skull characteristics

Answer 41

secondary cony palate enabling animal to suckle and breathe at same time, also to eat and breathe at same time - separates nasal cavity from oral cavity

Question 42

what is the most primitive group of mammals?

Answer 42

- prototherians - internal fertilization, egg-laying mammals - duck-billed platypus and spiny anteater - other names: echidna and monotherians

Question 43

what is the second major group of mammals?

Answer 43

- metatherians | - young nourished via primitive placenta in a pouch called marsupium

Question 44

types of marsupials

Answer 44

- kangaroo - koala - tasmanian devil - wombat - opossum

Question 45

what is the most advanced major group of mammals?

Answer 45

- eutherians | - true placental mammals

Question 46

types of eutherians

Answer 46

- dolphins - humans - cows

Question 47

endangered mammals

Answer 47

reasons for endangerment: - habitat loss - poaching - pesticides and other toxins - global warming