Lecture 26 Vertebrates - Mammals

Question 1

Three subclasses of Mammals

Answer 1

-Eutheria
-Prototheria
-Metatheria

Question 2

5 orders of the subclass Eutheria are

Answer 2

-Carnivora
-Cetacea
-Chiroptera
-Rodentia
-Sirenia

Question 3

One order of the subclass Prototheria is

Answer 3

Monotremata (platypus and short-beaked echidna)

Question 4

Two orders of the subclass Metatheria (Marsupialia)

Answer 4

-Diprotodontia
-Polyprotodontia

Question 5

The subclass Metatheria of Mammals is also called

Answer 5

Marsupialia

Question 6

All subclasses of mammals evolved from a

Answer 6

Common reptilian ancestor

Question 7

Monotremes evolved in

Answer 7

The Southern Hemisphere

Question 8

Monotremes retained four reptilian characteristics:

Answer 8

-oviparity
-meroblastic cleavage of embryo
-production of venom
-electroreception

Question 9

There are __ species of monotremes

Answer 9

5

Question 10

Which monotremes are found in Australia

Answer 10

-platypus
-short-beaked echidna

Question 11

The echidna has the

Answer 11

Widest environment range of any Australian mammal

Question 12

The platypus exists in

Answer 12

Freshwater habitats of eastern Australia

Question 13

Defining characteristics of monotremes (7)

Answer 13

-absence of calcified teeth (have a keratinised dental pad)
-electroreception used to detect prey
-reptile-like stance (limbs held off to side rather than under body)
-cloaca
-oviparity
-no teats (females produce milk through modified sweat glands)
-venom

Question 14

Crural glands are (4)

Answer 14

-venom glands found on the ankle of male platypus
-can move independently
-evolved independently of reptile venom
-used for defence of territories

Question 15

Electroreceptors are located

Answer 15

within the skin of bill/beak in platypus and echidnas

Question 16

The pectoral girdle of monotremes has

Answer 16

Reptilian features: coracoids, epicoracoids, and interclavicle

Question 17

Monotremes have multiple

Answer 17

X and Y chromosomes

Question 18

In marsupials and eutherian, sex is determined by ___

Answer 18

SRY on Y chromosome

Question 19

Monotremes lack

Answer 19

SRY on chromosome Y (ie. determines sex)

Question 20

The monotremes sex system is a

Answer 20

Link between birds and therians

Question 21

In the platypus, only the ___ is functional

Answer 21

Left ovary

Question 22

Monotremes have ___ but no ___

Answer 22

Mammary glands; teats

Question 23

The eggs of monotremes are (2)

Answer 23

-a porous, leathery shell
-developed in the uterus for ~20 days absorbing embryotrophe

Question 24

Echidnas incubate in ___ while platypus incubate in ____

Answer 24

Transient pouch; nest

Question 25

Not all marsupials posses

Answer 25

A pouch

Question 26

How many species of Marsupials

Answer 26

270

Question 27

Marsupials and eutherian diverged from

Answer 27

A common ancestor

Question 28

Marsupial young are born in an

Answer 28

Altricial state (ie. not developed yet)

Question 29

Marsupial young depend on ___ rather than ____

Answer 29

Lactation; gestation

Question 30

XX chromosome of marsupials results in (2)

Answer 30

-female reproductive tract -pouch

Question 31

XO chromosome in Marsupials results in (2)

Answer 31

-female reproductive tract -scrotum

Question 32

XY chromosome in Marsupials results in (2)

Answer 32

-male reproductive tract -scrotum

Question 33

XXY chromosome in marsupials results in (2)

Answer 33

-male reproductive tract -pouch

Question 34

Pouch OR scrotum development of marsupials depends on ___ and not___

Answer 34

X chromosome; hormonal control

Question 35

In marsupials, the ureters pass

Answer 35

Medially to Müllerian ducts

Question 36

Marsupials posses ___ from Müllerian ducts and ___ of connective tissues

Answer 36

Two lateral vaginae; median vagina

Question 37

Birth of marsupials occurs in the ___ vagina

Answer 37

Median

Question 38

In eutherian, ureters pass

Answer 38

Laterally to Mullerian ducts

Question 39

The Müllerian ducts is ___ in eutherian

Answer 39

Fused at the distal end to form the vagina

Question 40

The Müllerian ducts in marsupials is

Answer 40

Not fused

Question 41

The median vagina of marsupials is

Answer 41

Formed from connective tissue

Question 42

Marsupials replaced the role of ____ with ____

Answer 42

Gestation; lactation

Question 43

Marsupial young are born with (4)

Answer 43

-well developed forelimbs and claws -well developed mouth, tongue, nostrils, and lungs -no hair -periderm covering eyes and ears