OCR A Level Biology B (Advancing Biology)
OCR A Level Biology B Module 5: Genetics, Control and Homeostasis Exam Questions
Free OCR A Level Biology B exam questions for Module 5: Genetics, Control and Homeostasis, with a mark scheme for every pack. Covers inheritance, population genetics and epigenetics, gene technologies, the nervous system, vision, ageing, homeostasis, diabetes and the kidney.
Module 5: Genetics, Control and Homeostasis exam questions
9 question packs of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
StemUp mark scheme flashcards
A-Level Biology Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
From £10.99View flashcards
About OCR A Level Biology B Module 5: Genetics, Control and Homeostasis
Module 5 of OCR A Level Biology B (Advancing Biology) brings together genetics with nervous and hormonal control. It covers patterns of inheritance, population genetics and epigenetics, gene technologies, the structure and function of the nervous system and the effects of damage, the eye and visual function, the ageing nervous system, homeostasis, blood glucose control and diabetes, and kidney function and failure. Contexts often come from medicine, such as genetic screening or kidney dialysis. Examiners test genetic diagrams with chi-squared, Hardy-Weinberg, the action potential and synapses, insulin and glucagon, and nephron function.
What you need to know
- 5.1.1 Monohybrid and dihybrid inheritance, codominance, sex linkage, linkage and the chi-squared test.
- 5.1.2 The Hardy-Weinberg principle, genetic drift and selection in populations, and epigenetic control of gene expression through DNA methylation and histone modification.
- 5.1.3 PCR, gel electrophoresis, DNA sequencing, genetic engineering, genetic screening and gene therapy, with their ethical considerations.
- 5.2.1 Neurone structure, resting and action potentials, synaptic transmission, the organisation of the brain and nervous system, and the effects of injury to nervous tissue.
- 5.2.2 and 5.2.3 Structure of the eye, rods and cones and their pigments, tests of visual function, and changes to the nervous system and senses with ageing.
- 5.3.1 to 5.3.3 Negative feedback, control of blood glucose by insulin and glucagon, type 1 and type 2 diabetes, nephron structure and function, ADH, and kidney failure, dialysis and transplantation.
Common mistakes in Module 5: Genetics, Control and Homeostasis
- Saying epigenetic changes alter the DNA base sequence. Epigenetic changes, such as methylation, affect whether genes are expressed without changing the sequence.
- Writing that rods give colour vision. Cones give colour vision and high acuity; rods are more sensitive in dim light but give black and white vision.
- Saying glucagon converts glucose into glycogen. Glucagon stimulates glycogenolysis and gluconeogenesis, raising blood glucose.
- Describing type 2 diabetes as no insulin being made. In type 2, cells become less responsive to insulin, and secretion may also decline.
- Using 2pq to find the frequency of an affected recessive phenotype. Affected individuals are q^2; carriers are 2pq.
Try three Module 5: Genetics, Control and Homeostasis exam-style questions
1. A recessive condition affects 1 in 2 500 people. Use the Hardy-Weinberg equation to estimate the percentage of carriers. (3 marks)
Show the mark scheme answer
q^2 = 1 / 2 500 = 0.0004 so q = 0.02; p = 0.98; 2pq = 2 x 0.98 x 0.02 = 0.039, about 3.9%.
2. Explain why rods give greater sensitivity in dim light than cones. (3 marks)
Show the mark scheme answer
Several rods synapse with one bipolar neurone (retinal convergence); generator potentials from several rods summate; enough to reach threshold in dim light; rhodopsin is broken down by low light intensity.
3. Explain how ADH reduces water loss when blood water potential falls. (4 marks)
Show the mark scheme answer
Osmoreceptors in the hypothalamus detect the fall; posterior pituitary releases more ADH; ADH causes aquaporins to be inserted into collecting duct membranes; more water is reabsorbed by osmosis, giving small volumes of concentrated urine.
Module 5: Genetics, Control and Homeostasis FAQs
What does OCR A Level Biology B Module 5 cover?
Patterns of inheritance, population genetics and epigenetics, gene technologies, the nervous system and damage, visual function, ageing and the nervous system, homeostasis, blood glucose and diabetes, and the kidney.
How is Module 5 assessed in OCR Biology B?
Content from all modules can be assessed in each of the three A Level papers, so expect genetics and homeostasis to appear in different contexts.
Which calculations should I practise for Module 5?
Practise chi-squared tests for genetic crosses, Hardy-Weinberg allele and carrier frequencies, and rate calculations from nerve and kidney data.
