Sherpa

Existing user?

Biology

GCSE · AQA

QuestionsFlashcards

Communicable Diseases
Monoclonal Antibodies
- Producing Monoclonal Antibodies
  6
- Uses of Monoclonal Antibodies
  7
Plant Disease
- Detection and Identification of Plant Diseases
  6
- Plant Defence Responses
  6

Fossils Flashcards

All 6 cards in this deck

What are fossils?: The 'remains' of organisms from millions of years ago, which are found in rocks.
What are the three ways in which fossils may be formed?: From parts of organisms that have not decayed (one or more conditions for decay absent); when parts are replaced by minerals as they decay; as preserved traces of organisms.
True or false? A footprint preserved in rock counts as a fossil.: True. Preserved traces such as footprints, burrows and rootlet traces are fossils.
Why have many early forms of life left few traces behind?: They were soft-bodied, so they decayed without forming fossils.
Why can scientists not be certain about how life began on Earth?: Early soft-bodied life left few traces, and those traces have mainly been destroyed by geological activity.
Give one reason, other than soft bodies, why the fossil record is less clear for older species.: Older fossils are buried deeper so are harder to find (or are more likely to have been destroyed by geological activity).