IAL Biology Edexcel – Variation Exam Practice

Edexcel IAL Biology exam practice on variation (spec 3.21): four real WBI12 questions, a six-mark question with levels, and the misconception traps.

Lesson 31 of 32 · Topic 3 · Unit 2 (WBI12) · Spec 3.21 · 47 minutes
The question this lesson answers: how do I answer questions on variation, including the six-mark question?

By the end, students can

• Retrieve multiple alleles and polygenic inheritance and apply them to exam questions.
• Plan and write an extended answer on variation (a real six-mark question).
• Avoid the misconception traps that cost marks on this topic.

How the 19-slide lesson runs
A retrieval starter, then four real WBI12 questions, each with an official mark scheme and a full-mark model answer: January 2020 Q3, part b; January 2024 Q3, part c; October 2022 Q5; and the six-mark January 2022 Q6, part a, with indicative content and levels. A misconception-traps slide and an exit ticket close the lesson, with answers on the next slide.

Marks students usually lose here

• Explaining continuous variation with genes alone and leaving out the environment.
• Writing a six-mark answer as one long paragraph of definitions, with no linked points.
• Describing “the number of phenotypes” without saying how many alleles or genes cause it.

In the folder (13 files)

• PowerPoint, 3-page lesson plan and 11-page student notes with a one-page knowledge organiser
• 7 practice questions (21 marks) and mark scheme, each question on its own page
• 18-mark homework (a blood-group cross, polygenic inheritance, fruit mass controlled by two genes, plus spaced retrieval on splicing and meiosis) with mark scheme
• 5-question misconception check with teacher key
• 1 page of active-learning printables: Variation case files
• 5 pages of teacher notes (starter and exit mark points, a step-by-step run sheet for the active-learning activity, answer keys), plus catch-up and extension bank decks

Follows Lesson 30 (multiple alleles and polygenic inheritance); Lesson 32 is the topic review. The full 32-lesson Topic 3 bundle is in my shop.

An independent resource by bio_boffin_resources, written by a Biology teacher with 10 years’ experience in a leading international school. Not endorsed by Pearson.