Moderate

Enough protective ozone was built about how many years ago?

Correct answer: C. 420 billion

  • A. 320 million
  • B. 429 million
  • C. 420 billion
  • D. 320 billion

Explanation

About 420 million years ago, enough protective ozone had built up to make life on land possible. Ironically, the change from a reducing atmosphere to an oxidizing atmosphere also meant that life could no longer arise abiotically.

Last updated

About Evolution

Evolution describes heritable change in populations over generations through variation, natural selection and adaptation. Lamarckism explains inheritance of acquired characteristics, while Darwinism explains selection of favourable inherited variations; these historical explanations must not be confused with the modern genetic account of evolutionary change.

Practise Evolution

814 free Evolution MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Biology questions like this

Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions