Pearson Edexcel GCSE Biology tutors

For 1BI0, each written paper lasts 1 hour 45 minutes, carries 100 marks and contributes 50% of the qualification. Topic 1, Key concepts in biology, appears on both papers: keep revisiting it after Paper 1 preparation.

Both papers must be taken at the same tier. Use materials for the learner’s school-confirmed Foundation or Higher tier. Higher-only content is marked in bold in the specification. Both tiers require application and data interpretation. A learner may need to build an explanation from a labelled diagram before tackling an unfamiliar context; let a diagnostic question determine the starting point.

In this constructed practice example, a potato strip has an initial mass of 2.00 g. After soaking in a dilute sucrose solution and being blotted dry, it weighs 2.30 g. The task is to calculate its percentage change in mass and explain the result.

Percentage change = (final mass − initial mass) ÷ initial mass × 100.

(2.30 − 2.00) ÷ 2.00 × 100 = +15%.

The gain is 0.30 g. Calling this “0.30%” confuses a mass with a percentage; dividing by 2.30 g instead uses the final mass as the starting point. The original 2.00 g is the correct denominator.

A fuller response would be: “The strip gained 15% in mass. There was net movement of water into its cells by osmosis, through partially permeable cell membranes, from the more dilute solution outside to the more concentrated cell contents.” This joins the measurement to the biological mechanism.

Try the reverse: another 2.00 g strip ends at 1.80 g in a more concentrated solution. Its percentage change is (1.80 − 2.00) ÷ 2.00 × 100 = −10%. The negative sign means a loss: net water movement was out of the cells. A useful follow-up is to explain that direction without looking at the first answer.

To compare solution concentrations fairly, keep strip dimensions, soaking time and temperature consistent. Blot strips consistently before weighing so surface solution does not inflate the mass. The reason for each control matters as much as naming it.

Consider a second practice prompt: “An enzyme works more slowly after it is heated well above its optimum temperature. Explain why.” “The enzyme gets too hot and dies” does not explain the molecular change; an enzyme is not a living organism.

A better response is: “The enzyme becomes denatured. Its active site changes shape, so the substrate no longer fits as well and fewer enzyme–substrate complexes form. The reaction rate falls.” The substrate is the substance the enzyme acts on. Naming the active site is useful only when the answer explains how its changed shape affects the reaction.

This temperature question practises applying enzyme knowledge; Edexcel’s named enzyme core practical investigates pH. For a follow-up, give the learner a temperature–rate graph and ask them to identify the falling region and explain it using the same chain of reasoning.

Pearson’s extended-response guidance rewards connected reasoning that addresses the question and its context. For longer answers, practise ordering the explanation and using any supplied data. Six isolated facts are not a reliable recipe for six marks.