Fossils (AQA GCSE Biology Combined Science): Flashcards
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Practise the cards
9 cards from this deck
What are fossils?
What are fossils?
Preserved remains or traces of organisms from millions of years ago
Where fossils are typically found
Where fossils are typically found
Embedded in rock layers
Fossil formation: absence of decay
Fossil formation: absence of decay
Lack of oxygen/moisture prevents microbial decomposition
Fossil formation: mineral replacement process
Fossil formation: mineral replacement process
Organic parts (teeth, shells, bones) replaced by minerals
Examples of preserved traces (fossils)
Examples of preserved traces (fossils)
Footprints, burrows, rootlets
Fossils as evidence of...
Fossils as evidence of...
Evolution - show how anatomy changed over time
Use of fossils in comparative analysis
Use of fossils in comparative analysis
Compare species to construct evolutionary trees
Why are early life form fossils rare?
Why are early life form fossils rare?
Most were soft-bodied and decayed completely
Limitation: geological processes effect
Limitation: geological processes effect
Destroyed early traces via erosion, volcanic activity, tectonics