Chemical evolution. Archaean and Proterozoic
Answers are for parents and teachers.
1
Write the essence of the work of Oparin, Miller and Fox in one sentence each.
Oparin – the chemical evolution hypothesis and coacervates; Miller – amino acids from gases; Fox – proteinoids from amino acids.
2
Write the idea of the “RNA world” hypothesis.
RNA can store hereditary information and act as a ribozyme to speed up reactions, so it might have appeared before DNA and proteins.
3
What is a stromatolite and what is it evidence of?
A layered rock built by cyanobacteria; evidence of ancient photosynthesising life.
4
On a 4.5 m tape with 1 m = 1 billion years, at how many cm from the start (Earth’s formation = 0 cm, today = 450 cm) are the eukaryotes that appeared 2 billion years ago (450 − 200)? (Number only.)
250
5
Why was the ozone layer important for life on land?
It absorbs ultraviolet radiation and protects cell DNA from damage.