Amphibians

Question 1

How do amphibians differ from reptiles?

Answer 1

Moist, thin and permeable skin.
Lay eggs in water.
2 stage life cycle.

Question 2

What is the subclass lissamphibia?

Answer 2

The subclass containing all extant amphibians.

Question 3

What are the 3 surviving orders of amphibian?

Answer 3

Anura, Candata/Urodela and Gymnophonia/Apoda.

Question 4

What organisms are included in the order Anura?

Answer 4

Frogs and toads.

Question 5

What organisms are included in the order Urodela?

Answer 5

Salamander and newts.

Question 6

What organisms are included in the order Apoda?

Answer 6

Caecilians.

Question 7

Describe breathing in amphibians.

Answer 7

The presence of gills and lungs varies widely. Almost all species utilise cutaneous gas exchange - all 3 orders and all life stages.

Question 8

What are the advantages of permeable skin?

Answer 8

Allows for transcutaneous rehydration and cutaneous gas exchange with no energetic cost to ventilation.

Question 9

How do amphibians survive in desert environments?

Answer 9

Cocoon construction, water storage and urea accumulation - there are many others.

Question 10

Why are there so few British amphibians?

Answer 10

During the ice age 20,000 years ago there was a land bridge connecting Britain to Europe so they moved to the Mediterranean to avoid cold weather.

Question 11

How are frogs/toads “explosive breeders”? How does this contrast with newts/salamanders?

Answer 11

All adults migrate at once or within a short space of time in order to mate. Newts and salamanders have a prolonged breeding season.

Question 12

How do frogs, toads and newts differ in there egg laying strategies?

Answer 12

Toads swim, slowly releasing a chain of eggs.
Frogs rapidly eject all eggs in a few seconds.
Newts wrap their individual eggs in leaves close to water.

Question 13

What are the roles of amphibians in ecosystems?

Answer 13

Invertebrate population control nutrient cycling - transfer from aquatic to terrestrial.

Question 14

What are the main reasons for the global amphibian decline?

Answer 14

Habitat loss/alteration/fragmentation. 
Invasive species.
Climate change.
Chemical contaminants.
Disease.

Question 15

What are the main reasons for the global amphibian decline?

Answer 15

Habitat loss/alteration/fragmentation. 
Invasive species.
Climate change.
UV-B radiation. 
Chemical contaminants.
Disease.

Question 16

Why are amphibians particularly vulnerable to climate change?

Answer 16

They are very sensitive to changes in temperature and moisture.

Question 17

What does excessive UV-B radiation lead to in amphibians?

Answer 17

Immune disfunction and reduced growth.

Question 18

Why are amphibians medically important?

Answer 18

Some can regrow limbs and possess proteins that inhibit cancer growth.