unit 3 - AOS 1

Question 1

what is meant by the continental drift theory?

Answer 1

it is believed that all the continents once fit together like a puzzle, there is fossils of fauna that are unable to migrate found in multiple different continents.

Question 2

200mya

Answer 2

Australia was apart of the super continent, Pangea

Question 3

150mya

Answer 3

Pangea separated into Laurasia and Gondwana

Question 4

50 mya

Answer 4

Australia and Antartica begin to seperate form Gondwana

Question 5

present

Answer 5

finished separating, continue drifting northwards

Question 6

what is referred to by the term “megafauna”

Answer 6

large animal, was believed they existed prior to human habitation

Question 7

what are some theories of extinction?

Answer 7

1. aboriginals hunted their young as they were easier to kill, therefore they were unable to mature and regenerate
2. the hot climate, lead to limited water resulting in larger distances to travel to find it, while the changing landscape resulted in a reduced food source
3. BIOLOGIAL ISOLATION

Question 8

megafauna example

Answer 8

Procoptodon Goliath -
2-3m tall, up to 200kg

believed to be kangaroos ancestor

Question 9

what are the three characteristics that make Australia’s environment unique?

Answer 9

1. Biological Isolation
2. Geological Stability
3. Climatic Variation

Question 10

what is biological isolation?

Answer 10

Australia’s flora and fauna lost their ability to interact with other species, they had to adapt in isolation of predators, other species and food sources.

contributed to the uniqueness of the environment as as Australia has a large amount of endemic species

Question 11

specific example - biological isolation

Answer 11

KOALA
they are endemic to Australia, a lack of competition from other species or predators allowed the koala to adapt and evolve

Question 12

what is geological stability?

Answer 12

Australia is geologically stable as there are no major fault lines going through mainland Australia, resulting in little to no tectonic activity.

As a result there are no new fertile soils, rocks and soil are old as there is no volcanic activity to recycle them, resulting in nutrient poor soil.

Question 13

specific example - geological stability

Answer 13

BANKSIA
it has developed a cluster root system in order to enhance the availability of nutrients in the poor conditions

Question 14

what is climatic variation?

Answer 14

Australia’s landscape has experienced a range of different conditions from El Niño to La Niña

Question 15

what is referred to by El Niño

Answer 15

no rain, resulting in drought, therefore an increased risk of fires

Question 16

What is referred to by La Niña

Answer 16

periods of excessive rain, resulting in extensive flooding

Question 17

specific example - climatic variation

Answer 17

RIVER RED GUM
adapted to flooding by using the excessive amounts of water to germinate their seeds

EUCALYPTUS
adapted to the dry periods by having their leaves hang horizontal to limit the amount of sunlight they receive to minimise moisture loss

Question 18

fire as a form of climatic variation

Answer 18

plants have adapted to survive and thrive after large scale fires

Question 19

specific example - fire

Answer 19

GRASS TREES
they have a thick coating of dead leaved called a Sturt around the base to act as insulation to protect the trees stem from the flames and heat