FOSSILS, EXTINCTION AND SPECIATION

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What are fossils?
Fossils are the remains of organisms from many years ago - They are found in rocks
1 of 10
Name the three ways in which fossils form in rocks
From Gradual Replacement by minerals, From Casts and impressions, From preservation
2 of 10
Explain how fossils form from gradual replacement in minerals?
Teeth, shells, and bones don't easily decay. This means they can last longer when buried. When they do decay, get replaced by minerals. Minerals form rock like substance shaped like original
3 of 10
Explain how fossils form from casts and impressions?
Fossils can be formed when organism is buried in soft material, like clay. Clay hardens around it and organism decays. Organism leaves cast of itself. E.g. footprints pressed into soft materials leave impressions
4 of 10
Explain how fossils form from preservation in places where no decay happens
Decay microbes ONLY work if there's oxygen, moisture and warmth, and the right PH.
5 of 10
The fossil record contains many species that don't exist anymore - What is this called?
Extinction
6 of 10
Give three reasons why species become extinct
New predator, new disease, new species, catastrophic event, environment changes, competition
7 of 10
What is Speciation?
Speciation is when a new species develops
8 of 10
Populations of species can be seperated, e.g. due to a physical barrier. What is this called?
Isolation
9 of 10
Explain how Isolation could cause Speciation?
Floods, earthquakes can cause barriers that isolate some individuals from main population. Conditions on either side will be slightly different, e.g. different climates. Populations adapt to new environment. Development of new species
10 of 10

Other cards in this set

Card 2

Front

Name the three ways in which fossils form in rocks

Back

From Gradual Replacement by minerals, From Casts and impressions, From preservation

Card 3

Front

Explain how fossils form from gradual replacement in minerals?

Back

Preview of the front of card 3

Card 4

Front

Explain how fossils form from casts and impressions?

Back

Preview of the front of card 4

Card 5

Front

Explain how fossils form from preservation in places where no decay happens

Back

Preview of the front of card 5
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Comments

trying4law

On question 5, the answer suggests that the question should ask WHY fossils form from preservation in places where no decay happens, but other then that very good! 5 star :)

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