Topic 20- Amniote Evolution

Question 1

What are amniotes?

Answer 1

tetrapods who have gained an extra feature that allows them to disassociate the need for water for fertilization & allows them to emerge on land

Question 2

The amniote clade is ___ and ____

- the key unifying feature is an ____ ___ (ancestral condition)

Answer 2

mammals and reptiles

amniotic egg

Question 3

Amniotes use internal/ external fertilization.

Answer 3

internal

-They use copulation

Question 4

What does the amniotic egg provide?

Answer 4

• protects from desiccation (shell, chorion, amnion)
• gas exchange (allantois, chorion)
• nutrients (yolk)

Question 5

4 extraembryonic membranes form the ___ in mammals. List the 4

Answer 5

placenta

• amnion
• allantois
• chorion
• yolk sac

Question 6

Amniotes have waterproof skin (with ___). What does that do?

Answer 6

keratin

• reduces water lost to atmosphere
• less permeable- better protection
• must solely rely on lungs for gas exchange

Question 7

The buccal pump becomes replaced with ___

- there are muscles associated with the ____ __ to ventilate lungs

Answer 7

lungs

- rib-cage

Question 8

2 major clades of amniotes

Answer 8

1. reptilia (including birds)

2. Synapsida (includes mammals and numerous extinct taxa)

Question 9

of holes in skull used to classify amniotes. List the 3 skull types .

Answer 9

1. Anapsid: no holes (eg turtles)
2. Synapsid: 1 hole per side (eg mammals)
3. Diapsid: 2 holes per side behind eye socket: removes weight (eg. replilia, birds)

Question 10

The holes in skulls allow ____ to pass through to the jaw to control ___ ____

Answer 10

muscles

jaw movement

Question 11

Non-avian reptiles include/ exclude

Answer 11

includes turtles, crocodiles, lizards, snakes 
excludes birds (they're avian reptiles)

Question 12

the skin of non-avian reptiles is protected by thick, dry, ____ made of ___
- they ___the outer part

Answer 12

scales, keratin

shed

Question 13

describe the eggshell of non-avian reptiles

Answer 13

it is leathery to protect from desiccation

- a few species are viviparous, with extra-embryonic membranes acting as a placenta

Question 14

Reptiles are ___(ecto/endotherms) meaning they rely on ______ to maintain ________(___)

Answer 14

ectotherms

rely on environmental heat to maintain appropriate temperature (homeostasis)

Question 15

how do reptiles control body temp?

Answer 15

behaviorally.

they don’t expend metabolic energy on heating, meaning they need much fewer calories than say mammals !

Question 16

Reptiles care for their young ____ (except in ___)

Answer 16

little

crocodilians

Question 17

Order Testudines (___and __) have a ____(bony dorsal and ventral shield)

Answer 17

Turtles and tortoises

shell

Question 18

What kind of skull do turtles have? How many holes?

Answer 18

Anapsid (no holes other than the eye sockets)

Question 19

Male testudines have an intromittent organ, which : _________

Answer 19

is a genitalic structure to transfer sperm to female

Question 20

Why do turtles nest on land?

What do they eat?

Answer 20

• because their amniotic egg needs oxygen

- they are herbivores and carnivores, so they eat fish, jellyfish, etc

Question 21

Tuataras have teeth ____ to ___ ___

- do they copulate?

Answer 21

teeth fused to jaw bones

- yes, but they lack an intromittent organ

Question 22

order squamate includes ___ and ____

Answer 22

snakes, lizards

Question 23

squamates are characterized by: (list 2)

Answer 23

1. loosely jointed jaws and skull

2. paired hemipenes in male

Question 24

what do lizards have that snakes do not? (2)

Answer 24

external ear openings

well developed limbs

Question 25

What is responsible for no limbs in snakes?

Answer 25

snake enhancer

Question 26

compare how snakes and lizards eat their prey

Answer 26

snakes: they kill by suffocation (constriction) or venom lizards: bite and swallow prey (no not chew). a few are poisonous

Question 27

Like lizards, crocs do not ____

Answer 27

chew | they swallow prey whole or spin it to rip off chunks

Question 28

Male crocs have a single ____ ____ (like turtles)

Answer 28

intromittent organ

Question 29

explain how crocs care for their young

Answer 29

maternal care: - lay eggs in nest - guard nest - carry young in mouth, communicate with sound

Question 30

Which of the 6 challenges of terrestrial life have reptiles solved?

Answer 30

- gravity - desiccation: keratinized scales keep moisture in - respiration: lungs are ventilated with rib muscles and a 4-chambered heart - locomotion - They have NOT solved temp regulation (they're ectotherms)

Question 31

birds likely evolved from _______

Answer 31

theropods (small, fast dinos)

Question 32

are birds the first with feathers?

Answer 32

no, fossils suggest some dinos had feathers. Not used for flying, but display for mates

Question 33

Archaeopteryx shared a common ancestor with ___

Answer 33

modern birds

Question 34

What did Archaeopteryx have that modern birds do not? (3)

Answer 34

- teeth - bony tail - claws

Question 35

Considering theropods and birds, scales are ___(homo/analogous) with feathers

Answer 35

homologous

Question 36

similarities between theropods and birds (6)

Answer 36

- many theropods had feathers - hollow, thin-walled bones - similar respiratory systems - brain/ heart/ other organs similar - build nests - incubate eggs

Question 37

Class Aves is ___

Answer 37

birds

Question 38

Birds are ___(ecto/endothermic) | describe

Answer 38

endothermic - they use metabolic energy to maintain body temp - high rate of metabolism - feather & layer of fat help retain body heat

Question 39

disadvantage of ectotherms?

Answer 39

in a cold environment they may not be able to digest food; b/c they can't use metabolic energy to maintain body temp! They rely on the environment

Question 40

What are the 6 derived characters of birds? What do all of these adaptations do?

Answer 40

1. feathers 2. hollow bones 3. reduced # of forelimb digits 4. horny beaks that lack teeth 5. gizzard 6. reduced organs (poop and pee @ same time) reduce body weight! (enhances flight)

Question 41

what is a gizzard?

Answer 41

muscular part of stomach that grins hard food; an organ only found in birds

Question 42

How do birds reproduce?

Answer 42

Internal fertilization (copulation) but most do not have intromittent organ (except ostriches, waterfowl)

Question 43

What is the Cloaca?

Answer 43

a common opening for digestive, urinary, and reproductive tract - in birds, reptiles, amphibians - male and female birds press cloacas together to transfer sperm

Question 44

young birds are cared for by mother or both parents. Define: 1. precocial: 2. altricial:

Answer 44

1. young may be able to feed themselves | 2. born helpless and featherless

Question 45

flightlessness has evolved _____many times in birds

Answer 45

secondarily

Question 46

what challenges of terrestrial life have birds solved?

Answer 46

``` gravity desiccation respiration reproduction locomotion temp regulation (ALL OF THEM!) ```