Selective Breeding & Food Chains

0–5 min | Starter Activity – Think & Pair

Question on board:

Why do farm animals look very different today compared to animals in the wild?

• Students write one idea
• Pair and share
• Teacher collects responses (growth, size, milk, eggs, meat)

5–25 min | Section A: Selective Breeding of Farmed Animals

1️⃣ What is Selective Breeding? (5 mins)

Teacher explanation (KS3 level):
Selective breeding is when humans choose animals with certain characteristics to breed together, so their offspring show those traits.

Common traits selected for:

• Faster growth, More meat, milk or eggs, Specific body shape, Calm behaviour

2️⃣ Video: Overview of Selective Breeding (5 mins)

Play:
🎥 Overview of Selective Breeding (GCSE Biology) – Cognito (4:04) VIDEO   https://www.youtube.com/watch?v=In6Rl3Q2THQ

While watching – students note:

• One benefit of selective breeding
• One problem caused by selective breeding

3️⃣ Impacts of Selective Breeding – CIWF Case Studies (10 mins)

Replay 2 sections from the CIWF video [4:15 seconds in total]

https://www.ciwf.org.uk/education/films/farm-animals-us/:   

• Intensive chicken farming – selective breeding (@5:47)
• Intensive dairy farming – effects of selective breeding (@9:02)

Teacher-led discussion using CIWF Teacher Notes: https://www.ciwf.org.uk/media/5262846/Science-worksheets-compilation-booklet.pdf

Pros of selective breeding:
✔ More food produced ✔ Cheaper food prices ✔ Predictable animal traits

Cons of selective breeding:
✖ Health problems (e.g. weak legs, breathing issues) ✖ Reduced genetic diversity
✖ Animal welfare concerns ✖ Animals bred beyond natural limits

🔍 Mini Check Question:

Is selective breeding always harmful, or does it depend on how it is used?

25–30 min | Plenary Question (Section A)

Whole-class discussion:

Should animal welfare come at the expense of cheap food?

Encourage: Evidence from videos, Balanced viewpoints, Respectful discussion

30–40 min | Section B: Food Chains & Farmed Animals

1️⃣ Introduction to Food Chains (3 mins)

Teacher explanation:
A food chain shows how energy moves from one living thing to another.

Key terms: Producer, Consumer, Predator, Energy loss

2️⃣ Video: KS3 Food Chains (2 mins)

🎥 BBC Bitesize – Food Chains (52 seconds) https://www.youtube.com/watch?v=pfLHMmsftG4   

Quick recap:
Energy decreases at each level of the food chain.

3️⃣ Farmed Animals in Food Chains – CIWF Video (5 mins)

Replay 2 sections from the full video: https://www.ciwf.org.uk/education/films/farm-animals-us/

• Food chains & efficient food production (Starts @13:30)
• Alternative systems & personal choices (Starts @14:45)

Key teaching points:

• Animals eat plants → humans eat animals
• Energy is lost at each step
• Feeding crops to animals is less energy-efficient than feeding humans directly

40–50 min | Applying Food Chains to Farming Systems

Comparison Discussion (Teacher-led) Teachers Notes, lesson plan and worksheet https://www.ciwf.org.uk/media/5262846/Science-worksheets-compilation-booklet.pdf

Animal-based food chain:
Plants → Animals → Humans

• More energy loss
• More land, water, and crops needed

Plant-based food chain:
Plants → Humans

• Fewer steps
• More energy efficient
• Less resource use

Link to sustainability:

• Climate impact
• Land use
• Global food security

50–55 min | Final Plenary – Exit Quiz – Answers:

1. B
2. A
3. B
4. B
5. D
6. D
7. B
8. A
9. C
10. B