Explain why comparing the amino acid sequences of a protein can show relationships between species more reliably than comparing observable features.
From Mock B · Paper 1 (topics 1–4)
10.23 marks
Two populations of a snail had mean shell lengths of 21 mm (SD 1.2) and 24 mm (SD 3.5) (data are illustrative, written for this paper). Compare the variation in the populations and explain what the standard deviations show.
From Mock C · Paper 3 (all topics, practical skills and essay)
57 marks
Leaf lengths of a plant from sunny and shaded sites (n = 30 each) (data are illustrative, written for this paper): sunny mean 42 mm, SD 4.1; shaded mean 58 mm, SD 6.3. A t-test gave t = 11.6 (critical value 2.00 at P = 0.05).
(a) State a null hypothesis. (b) Interpret the t-test result. (c) Suggest an explanation for the difference. (d) Explain why the samples should be collected at random.
Score 0 / 12 · 0 of 3 marked
This paper is written by Plasmo in the style of the AQA A-Level Biology exam. It is not a past paper and is not produced or endorsed by the exam board.