Topic 5C

Question 1

RNA world hypothesis

Answer 1

postulate that RNA was the original information-storage molecule in the earliest forms of life on Earth

Question 2

trace fossils

Answer 2

fossils of animal tracks and trails in sediments that preserves a record of both anatomy and behaviour

Question 3

geologic timescale

Answer 3

the series of time divisions that mark Earth’s long history; can be recorded by fossils

Question 4

radiometric dating

Answer 4

a method that uses the radioactive decay of carbon-14 to date wood and bone

Question 5

mass extinctions

Answer 5

rapid and substantial drops in diversity often through large extinctions