6.1 Origins of Life on Earth Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

How old is the Earth?

A

4500 million years old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When did life begin on Earth?

A

3500 million years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where are fossils found?

A

In rocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many ways are there that fossils can be formed?

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the four ways fossils can be formed?

A

From the hard parts of animals that do not decay easily e.g. bones, teeth
Parts of organisms that have not decayed because the conditions of decay are absent e.g. in ice
When parts of an organism are replaced by other materials such as minerals when they decay
Preserved as traces e.g. footprints, burrows and rootlet traces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are traces of animals likely to have been destroyed?

A

In earthquakes (geological activity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does extinction mean?

A

A species that once existed has completely died out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What can we learn from the fossil record?

A

How organisms have changed over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are 5 reasons a species may become extinct?

A
A new disease
Environment changes over geological time
New predators and competitors
A single catastrophic event e.g. volcano eruption
Natural changes in a species over time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What has the biggest influence on extinction?

A

Changes in the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the two ideas that have been suggested on why dinosaurs may have become extinct?

A

A giant asteroid hit the earth and caused fires, earthquakes, landslides and tsunamis. Dust rose and masked the sun causing darkness and lower temperatures
or
The extinction was a slower process; sea ice melted, cooled the sea, less plankton food available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly