Animal biodiversity 6 - tetrapods

Question 1

what 3 things drove the movement out of the sea onto land?

Answer 1

1) drying conditions in the late devonian
2) prey on shore
3) escaping from predators

Question 2

what 2 adaptions to life in shallow swamps of the first tetrapods helped them move onto land?

Answer 2

1) strong bones in fin

2) lungs and nostrils

Question 3

describe the evolution of fingers in amphibians and what they resemble?

Answer 3

evolved fewer but stronger fingers closely resembling lobe finned fishes

Question 4

what 4 features of the Lobe-finned Actinistian ancestor are close to tetrapods?

Answer 4

1) fin structure
2) braincase
3) strong skeleton
4) teeth

Question 5

what 4 features of the Lungfish Dipnoi ancestor are close to tetrapods?

Answer 5

1) lungs
2) nostrils
3) egg and larval stages
4) mitochondrial DNA

Question 6

what period did the class amphibia dominate and why but also why did it end?

Answer 6

carboniferous because loads of food and no predators but the reptiles lead to decline

Question 7

what gives amphibia their name?

Answer 7

they have 2 stages in life = larval to adult

Question 8

name 6 challenges to adapting to life on land

Answer 8

1) UV light
2) physical support
3) sensory modification (sight and sound)
4) variable temp no longer buffered by ocean
5) loss of water through air and skin
6) drying out of sperm and eggs in external fertilisation

Question 9

what are the adaptations of amphibians epidermis and what do they help to protect against?

Answer 9

1) they have pigments (chromatophores) to protect against UV
2) keratin and mucus to prevent water loss

Question 10

what adaptation of amphibians controls gas exchange?

Answer 10

capillaries at the surface of the skin can permit gas exchange but limit the range

Question 11

what 4 adaptations to amphibians skeleton help to support them on land?

Answer 11

1) strong vertebrae that interlock to walk on land
2) pentadactyl limb
3) ribs attaching pelvic girdle to vertebrae
4) pectoral (shoulder) girdle held in place by muscles giving flexibility

Question 12

3 ways amphibians sensory modes adapted?

Answer 12

1) ear
2) change in eye shape with tear ducts
3) lateral line system lost in adults

Question 13

2 metabolic adaptations in amphibians?

Answer 13

1) divided intestine

2) 3 chambered heart

Question 14

what are 4 limits to amphibians life on land?

Answer 14

1) dehydrate quickly
2) require water for reproduction
3) aquatic larvae( tadpoles) require water
4) no internal temp so have to hibernate

Question 15

what is the significance of Labyrinthodonts?

Answer 15

the earliest semi aquatic amphibians which gave rise to reptiles

Question 16

what are the 3 orders of amphibians?

Answer 16

tailed ones
tailless
legless

Question 17

where do the order urodela live?

Answer 17

either aquatic or terrestrial

Question 18

where are the order anura suited to?

Answer 18

better adapted to terrestrial life with powerful hind legs for jumping

Question 19

where are the order apoda found?

Answer 19

underground

Question 20

name 6 reasons for decline in amphibian diversity?

Answer 20

1) invasive predators
2) climate change (drying out of ponds)
3) loss of habitat
4) disease
5) toxic substances
6) UV radiation

Question 21

describe the steps of a process starting with global warming leading to increased moralities and deformities in amphibians

Answer 21

1) global warming
2) reduced pond depths
3) increased UV on eggs
4) reduced disease resistance
5) high rates chytrid infection
= mortality and deformities