scholarlab.KS4 Biology
Logic Lab route
LOGIC LAB · MODULE 2

Long answers (4 to 6 marks)

By the end you can: plan and write a 4 to 6 mark explanation as a chain, one creditable point per mark.

Starting here

A 4 to 6 mark Explain question is marked point by point. Count the marks, then plan that many separate points.

Write a chain: each step causes the next. Use the key term (diffusion, denatured, active site) in each step. Do not repeat a point in new words: it scores once.

Key ideas

  • Marks = points to make
  • One step per sentence, joined with so
  • Key terms earn marks
  • Repeats score once
Four boxes joined by arrows: Point (the first cause), so (what it leads to), so (the next effect), so (the answer). Below: more light leads to faster photosynthesis, more glucose and more growth.One link per markPointthe first causesowhat it leads tosothe next effectsothe answerExample: more light → faster photosynthesis → more glucose → more growth
A 4 to 6 mark explanation is a chain. Each arrow is a step the examiner can credit, so do not jump from the first box to the last.

Worked example

Explain why a plant in a sealed jar in bright light grows more slowly once the carbon dioxide runs out. (4 marks)

  1. Point 1. Carbon dioxide is a reactant in photosynthesis.
  2. Point 2. So with less carbon dioxide, the rate of photosynthesis falls: carbon dioxide is now the limiting factor.
  3. Point 3. So less glucose is made.
  4. Point 4. So there is less glucose for respiration and to make cellulose and proteins for new cells.

Answer: Four marks, four linked steps. Each one uses a key term.

Activities

0 of 4 done

Opens when you finish the stage above.

Now we’ll build those skills by…

…building chains step by step, then spotting the missing link.

Opens when you finish the stage above.

Check

5 questions. One try each: get 4 right to complete the module.

Opens when you finish the stage above.