GRADE 11 POPULATION ECOLOGY SLIDES.part 1

population ecology

1. POPULATION ECOLOGY GRADE 11 INTERACTION IN THE ENVIRONMENT

2. LESSON OBJECTIVES: Learners will list the different interactions in the environment Learners will define predation, competition, specialisation, parasitism, mutualism, and commensalism . Learners will give two South African examples of each interaction.

3. CONCEPT MAP: INTRODUCTION

4. BIG QUESTION OF THE DAY WE KNOW ECOLOGY IS THE STUDY OF INTERACTION IN AN ECOSYSTEM, BUT HAVE YOU EVER THOUGHT ABOUT….. WHAT KINDS OF INTERACTIONS EXIST BETWEEN MEMBERS OF THE SAME AND NOT DIFFERENT SPECIES?

5. Types of interactions: Predation 🦁🦓 Specialisation 🐦🌳 Parasitism 🦠🐄 Mutualism 🌸🐝 Commensalism 🐦🦒 Competition 🐦🌸

6. PREDATION One organism ( predator ) kills and eats another ( prey ). Controls prey population 🦓➡️🦁 Predator depends on prey for food 🍽️ Examples (SA): 1️⃣ Lion & Zebra – Kruger National Park 🦁🦓 2️⃣ Cape Fur Seal & Cape Gannet – Coastal waters 🦭🐦 📊 Predator–prey cycles : Prey ↑ → Predator ↑ → Prey ↓ → Predator ↓ 💡 Keeps ecosystems balanced!

7. Parasitism Parasitism = One species ( parasite ) benefits, the other ( host ) is harmed but not killed immediately 🦠🐄 Parasite gets food, shelter, or resources from the host 🛌🍽️ Host loses energy, nutrients, or health 😷 Examples (SA): 1️⃣ Tick & Buffalo – Tick feeds on buffalo’s blood 🐃🪳 2️⃣ Tsetse Fly & Cattle – Fly spreads sleeping sickness 🐄🪰 💡 Why it matters: Parasites can control host populations and spread disease 🩺

8. MUTUALISM Mutualism = Both species benefit from the relationship 🤝🌱 Helps both survive, grow, or reproduce 🐦🌸 Often long-term partnerships 💚 Examples (SA): 1️⃣ Oxpecker & Buffalo – Bird eats ticks, buffalo gets pest control 🐃🐦 2️⃣ Aloe Plant & Sunbird – Sunbird gets nectar, aloe gets pollinated 🌺🐦 💡 Why it matters: Boosts biodiversity and helps ecosystems stay healthy 🌍

9. Commensalism Benefiting species gains food, shelter, or transport 🛖🚗 The unaffected species is neither helped nor harmed 🙂 Examples (SA): 1️⃣ Barnacles & Whales – Barnacles get transport & food particles 🐋🦪 2️⃣ Cattle Egret & Livestock – Egret eats insects stirred by grazing animals 🐄🐦 💡 Why it matters: Allows one species to thrive without harming others 🌱

10. SUMMARY Different species interact in many ways: Predation – Predator kills and eats prey 🦁🦓 Commensalism – One species benefits, the other is not affected 😎 🦌🌿 Parasitism – One benefits, one is harmed 🐃🪳 Mutualism – Both benefit 🐦🌸💡 Why it matters: Shapes population sizes 📊 Helps maintain balance in ecosystems ⚖️ Increases biodiversity 🌱