Mammals Part I

Question 1

How many species of mammals are there?

Answer 1

5000 species

Question 2

what the 3 unique features of mammals?

Answer 2

1. hair: insulation, camouflage, sensory and defence

Question 3

what the 3 unique features of mammals?

Answer 3

2. sweat glands

Question 4

what the 3 unique features of mammals?

Answer 4

3. mammary glands

Question 5

skull types of amniotes: anapsids

Answer 5

turtles

Question 6

skull types of amniotes: synapsids

Answer 6

terapsids and mammals

Question 7

skull types of amniotes: euryapsids

Answer 7

extinct marine reptiles

Question 8

skull types of amniotes: diapsids

Answer 8

dinosaurs and birds

Question 9

what is the key difference between skull size presence, size and number of temporal fenestrae:

Answer 9

holes that provide more surface area for muscle attachment

Question 10

when did true mammals evolve?

Answer 10

around 225 mya - Triassic

Question 11

Different morphological states of middle ear of mammals: MME

Answer 11

mandibular middle ear

Question 12

Different morphological states of middle ear of mammals: TMME

Answer 12

transitional mandibular middle ear

Question 13

Different morphological states of middle ear of mammals: DMME

Answer 13

definite mammalian middle ear

Question 14

what did the development of the middle ear allow?

Answer 14

mammals to hear at higher frequencies than reptiles

Question 15

mammals did not radiate until the extinction of??

Answer 15

dinosaurs

Question 16

the ambulocetus is the ancestor to

Answer 16

whales

Question 17

megatherium were

Answer 17

herbivourous and elephant sized

- giant ground sloth

Question 18

how did smilodons go extinct?

Answer 18

hunting of humans

Question 19

features of mammalia

Answer 19

endothermic

Question 20

features of mammalia

Answer 20

advanced nervous system

Question 21

features of mammalia

Answer 21

internal fertilization

Question 22

features of mammalia

Answer 22

unlike reptiles and fish, mammals also show heterodonty

Question 23

heterodonty

Answer 23

different teeth specilized for tasks

Question 24

features of mammalia

Answer 24

specilization in teeth among species = varied diets

Question 25

features of mammalia

Answer 25

4 chambered heart

Question 26

Prototherians

Answer 26

- monotremes - egg laying - egg incubation until hatching - have mammary glands - playtpus, echidna

Question 27

marsupials

Answer 27

- pouched | - early birth, fetus completes development in pouch

Question 28

Eutherians

Answer 28

- placental | - embryo retained in female reproductive tract

Question 29

where did platypus (PERRY THE PLATYPUS) originate from?

Answer 29

eastern australia

Question 30

what do platypus use their bill for?

Answer 30

use bill to dig for custaceans and worms

Question 31

how many eggs do playpus lay?

Answer 31

2-4 eggs

Question 32

the platypus bill acts like a

Answer 32

sonar system - similar to electric fish, bill of playtpus has a mechano- and electro receptors that allow organism to create a map with field lines that determine the location of prey

Question 33

Echidna are known as

Answer 33

"spiny anteaters"

Question 34

Marsupials do not

Answer 34

lay eggs

Question 35

marsupials have short ___ and long ___ ___

Answer 35

gestation; nursing periods

Question 36

what is the largest marsupial carnivore?

Answer 36

tasmanian devil

Question 37

why are Tasmanian devils extinct?

Answer 37

due to hunting and dingos

Question 38

94% of mammals are

Answer 38

eutherians

Question 39

eutherians have an

Answer 39

amniotic egg retained in the female reproductive tract

Question 40

Eutherians are often referred to as

Answer 40

placental animals - but some marsupials have placentas too

Question 41

placenta

Answer 41

organ formed by the embryo and mother after implantation

Question 42

how was the placenta formed?

Answer 42

by extra-embryonic membranes and uterus lining of the mother

Question 43

what occurs in the placenta?

Answer 43

gas, nutrient and waste exchange between the mother and the embryo

Question 44

how do substances pass between the mom and fetus?

Answer 44

by diffusion

Question 45

what moves across the placenta?

Answer 45

- small molecules - urea - nutrients - hormones - alcohol and drugs...