Class Tetrapod, Midsession quiz

Question 1

CLASS AMPHIBIA
What are the 3 orders of Amphibians?

Answer 1

1. Order Gymnophiona
2. Order Caudates
3. Order Anura

Question 2

GYMNOPHIONA
What are the Defining features of this order?

Micro and Macrohabitat?

Answer 2

Caecilians

Defining Features:
Burrowing Anuli
Internal Fertilisation
Limbless
Sensory tentacle

Eggs can be laid;
In Water: Gilled larvae, become terrestrial after metamorphing
Underground: Young hatch as small adults.

Microhabitat:
Moist, loose soil
Near Streams
tropical rainforests

Macrohabitat:
South America

Question 3

CAUDATA

What are the defining features of this order?

Answer 3

Salamanders & Newts

Defining features:
Limb regeneration
Internal/external fertilisation
Entirely terrestrial
PAEDOMORPHIC
Breed in water; Larvae
Merge to land until ready to breed again
Skin is a respiratory organ
Alternate undulations (limbs)

Microhabitat:
Damp/Wet areas

Macrohabitat:
Northern Hemisphere
America, Europe Asia, Japan

Question 4

Define Paedomorphic

Answer 4

Retaining juvenile characteristics as adults

Question 5

ANURA

What are the defining features of this order?

Answer 5

Frogs

Defining features;
Bulging eyes aid swallowing
Buccal pump
Specialised skeleton for jumping, swimming
Oviparous - require water
Aestivation - torpor
freezing frogs

Metamorphosis;
1. tadpole structure break down, chemical constituents rebuild to adult structure
2. loss of gills/lung development
3. Hormonally controlled

Microhabitat
Moist

Macrohabitat
Globally excluding antartica

Question 6

What are the 2 major groups of amniotes?

Answer 6

1. Synapsids
2. Sauraposids

Question 7

SYNAPSID

Answer 7

SYNAPSID
- mammals
- Synapsid skull
- evolved earlier
- forelimbs more developed than hind
- DIAPHRAM
- Better Olfaction, poor Vision
** Synapsids were once more successful than Sauropsids until the Permian Mass extinction ~245 mya, called the ‘Triassic takeover’**

Question 8

SAUROPSID

Answer 8

SAUROPSID
- Lizards, snakes, turtles, crocodiles, birds
- Diapsid Skull (NOT TURTLES)
- Better Vision, poor olfaction
- Hindlimbs are more developed than forelimbs
- GASTRALIA- rib-like structure on front of chest

Question 9

What is the most defining feature of all Amniotes?

Answer 9

Amniotic egg
Amniotic sac in placental mammals
Double circulation

Question 10

Name the important structures within the Amniotic egg

Answer 10

Allantois
Yolk
Chorion
Amnion

Question 11

What is the function of the Yolk in the amniotic egg?

Answer 11

Provides nutrients and water for embryo
Fuel
When embryo uses up nutrients, the yolk shrinks

Question 12

What is the function of the Allantois in the amniotic egg?

Answer 12

‘bladder’ storing nitrogenous waste
gas exchange

Question 13

What is the function of the Chorion in the amniotic egg?

Answer 13

Encloses yolk, embryo and allantois
Facilitates gas exchange w/ exterior

Question 14

What is the function of the Amnion in the amniotic egg?

Answer 14

Encloses embryo
provides cushion against mechanical shock

Question 15

How has the amniotic egg allowed life on land?

Answer 15

1. Doesn’t require a water source
2. Self-sustaining environment
3. Mammals, other than monotremes, develop the same amniotic layers but inside the womb
4. Less pool competition - dispersal on terrestrial land
5. Decreased predation
6. Higher chance of survival off offspring (fewer in numbers though)

Question 16

How do endotherms insulate themselves?

Answer 16

High MR
Insulation

Question 17

Endothermy

Answer 17

Mammals and birds
internally thermoregulate

Question 18

Ectothermy

Answer 18

Reptiles and Crocs
Rely on external heat sources

Question 19

Evolution of Endothermy

Answer 19

Erect Gait, bipedal (upright posture) BIRDS
Jaw structure
Palate
Turbinates (humidity and breathing)

Question 20

Why are amphibians vulnerable during metamorphosis?

Answer 20

Low immune competence due to the reorganising of essential molecular pathways (limbs)
High energetic cost of tissue reorganisation
Low nutrition - Don’t feed themselves during

*Tadpole structure breaks down, chemical constituents rebuild into adult structure *

Question 21

What are the 5 abiotic challenges that tetrapods face?

Answer 21

1. UV
2. Gravity
3. Desiccation
4. Reproduction
5. Temperature

Question 22

Solutions to Abiotic factors:

1. UV radiation

Answer 22

Behavioural avoidance
Protecting exposed surfaces
Scales, feathers, Fur
Skin pigmentation

Question 23

Solutions to Abiotic factors:

2. Gravity

Answer 23

Structural support & musculature
Endoskeleton
favours terrestrial locomotion
Joints and muscles

Question 24

Solutions to Abiotic factors:

3. Desiccation

Answer 24

Reptiles and birds can repackage ammonia
Concentrates urine in mammals
Rectal recovery of excretory fluids (dry faeces)
Salt excreting glands

Question 25

Solutions to Abiotic factors:

4. Reproduction

Answer 25

Amniotic Egg

Question 26

Solutions to Abiotic factors:

5. Temperature

Answer 26

Thermoregulation
Endo/Ectothermy
Behavioural Strategies
- Hibernation
- Torpor
- aestivation
Cold hardiness + freezing in frogs

Question 27

What are the circulatory and respiratory adaptations of amphibians?

Answer 27

RESPIRATION
Buccal pump in frogs
Breathing through skin

Consequences:
Breathing through the skin can result in the inhalation of harmful chemicals in the air

CIRCULATION
3 cambers
Mixing
WHY?
Lower MR, don’t require much oxygen to be delivered to the body

Question 28

What are the circulatory and respiratory adaptations of birds?

Answer 28

RESPIRATION
most efficient in the animal kingdom
Unidirectional (racetrack)
Negative pressure breathing
Rib + pelvic movements to inhale
9 air sacs in birds
Continuous flow of air through lungs, expells extra heat from the body
Makes flying possible

CIRCULATION
4 Chambers
Single aorta
High MR
Complete separation of Left and right heart

Question 29

What are the circulatory and respiratory adaptations of crocodiles?

Answer 29

RESPIRATION
Unidirectional (racetrack)
Negative pressure breathing
Rib + pelvic movements to inhale
Fewer but still some air sacs in crocs
(posterior is main air sac)

CIRCULATION
4 Chambers
Crocs: cog tooth valve (diving) restricts blood flow to lungs
COG TOOTH lowers MR allowing for longer diving times
some mixing
2 aortas
Ectotherms, due to slight mixing and their sit-and-wait behaviour when hunting, does not require them to be warm-blooded.

Question 30

What are the circulatory and respiratory adaptations of Mammals?

Answer 30

RESPIRATION
Bi-directional (waves at a beach)
Negative pressure breathing
Diaphram
Bi-pedal, erect gaits
Highly efficient

CIRCULATION
Same as Avian
1 Aorta
4 chambers
Complete separation of chambers
No mixing
Double circulation

Question 31

What mechanisms have birds developed to fly?

Answer 31

LIFT: BERNOULLI PRINCIPLE
Side of wing with fast flow (above) has a lower pressure

The side of wing with slower airflow (below) has a higher pressure

Results in an uplifting force
Pressure is generally always higher below wings
pressure difference drives birds off the ground

THRUST:
Sweep air providing a forward motion
High powered downstroke
Low powered Upstroke

Question 32

Defining features of Amphibians

Answer 32

Skin must always be wet to allow for skin respiration

Aquatic/require moist environments

Start off as larvae

Anapsid skull