Skip to content

Course home

Sign up

6.4 Classification of living organisms

EasyMediumHard
12345678910111213141516171819202122232425262728293031
Question 2

Scientists classify four living species of marine worm, J, K, L and M.

An older classification placed J with K and placed L with M because of similarities in their external feeding structures.

Scientists compared many corresponding DNA regions from the four species.

Pair of speciesNumber of different DNA bases
J and K410
J and L86
J and M500
K and L470
K and M102
L and M560

Two evolutionary trees are proposed:

  • Tree 1 shows J and K sharing the most recent branch, and L and M sharing the most recent branch.
  • Tree 2 shows J and L sharing the most recent branch, and K and M sharing the most recent branch.

Which proposed tree is best supported?

Explain how the evidence supports your choice and why the older classification may be revised.

[3]
Markscheme

6.4 Classification of living organisms Questions

  1. GCSE
  2. /Biology
  3. /6.4 Classification of living organisms

81 exam-style questions on AQA GCSE Biology 6.4 Classification of living organisms, covering 6.4 Classification of living organisms. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank