What is Selective Breeding and How Does it Work? Revision Notes | GCSE OCR Foundation Biology

What this lesson covers

Understand the process of selective breeding and learn about examples including disease-resistant crops, high-yield animals, gentle dogs, and decorative...

• Explain what selective breeding is and how humans have used it for thousands of years
• Describe the process of selective breeding over multiple generations
• Evaluate examples of selective breeding in crops, animals and pets
• Compare the advantages and disadvantages of selective breeding programmes

Key ideas to keep in view

Use this lesson to stay inside B5.2 Natural selection and evolution while connecting the detail back to the wider B5: Genes, inheritance and selection topic.

• B5: Genes, inheritance and selection
• B5.2 Natural selection and evolution
• GCSE OCR Foundation Biology

Lesson notes preview

Read the core explanations from What is Selective Breeding and How Does it Work? before testing yourself from memory.

• Every dog you see - from tiny Chihuahuas to massive Great Danes - descended from wolves. Every wheat plant in a field producing bread flour came from wild grasses that barely had any edible seeds. How did this transformation happen?
• The answer is selective breeding. Humans have been shaping the living world around them for over 10,000 years, choosing which plants and animals get to reproduce based on the traits we find useful.
• The process by which humans breed plants and animals for particular genetic characteristics. Also called artificial selection.
• Trap: Many students think selective breeding is 'creating new genes'. Actually, we're just choosing which existing genes get passed on more often. The genes were already there in the population - we're just changing their frequency.
• The process sounds simple, but it requires patience and careful planning over many generations. Here's how it works step by step.
• The key insight is that this takes many generations. You can't create a super-cow in one breeding season. Each generation, the average gets slightly better as the genes for high milk production become more common in the population.
• Selective breeding has given us most of the food we eat and the animals we live with. The characteristics chosen fall into two main categories: usefulness and appearance.
• Disease resistance in food crops: Farmers select wheat plants that survive fungal infections, then breed only from these survivors. Over generations, the crop becomes naturally resistant to disease without needing pesticides.
• Animals that produce more meat or milk: Dairy farmers choose cows producing 30+ litres of milk daily. Pig farmers select breeding stock with larger muscle mass and less fat. This increases food production efficiency.
• Domestic dogs with gentle nature: Over thousands of years, humans selected wolves and early dogs that were less aggressive and more cooperative. This gave us breeds like Golden Retrievers and Labradors that are naturally friendly.

Continue through the topic

Move to the related lessons or back to the topic page when you need the wider sequence before exam-style practice.