Competition and Survival in Communities Revision Notes | GCSE OCR Foundation Biology

What this lesson covers

Explore how organisms compete for resources in their habitats, including what plants and animals compete for, and how organisms are adapted to survive i...

• Explain how organisms compete for resources in their habitat
• Identify the factors that plants and animals compete for
• Describe adaptations that help organisms survive in their environment
• Suggest how competition affects the survival of organisms in a community

Key ideas to keep in view

Use this lesson to stay inside B4.1 Ecosystems while connecting the detail back to the wider B4: Community level systems topic.

• B4: Community level systems
• B4.1 Ecosystems
• GCSE OCR Foundation Biology

Lesson notes preview

Read the core explanations from Competition and Survival in Communities before testing yourself from memory.

• Picture a woodland in spring. Hundreds of bluebells are sprouting, but only some will flower. Squirrels are searching for nuts, but there aren't enough for everyone. This isn't random - it's competition, and it determines who lives, who dies, and who gets to reproduce.
• Competition happens when organisms need the same resources but there isn't enough to go around. It's like a game of musical chairs - when the music stops, not everyone gets a seat.
• The struggle between organisms for the same limited resources in a habitat. Occurs when resources are not abundant enough for all organisms.
• Trap: Many students think competition only happens between different species. Actually, the fiercest competition is often between members of the same species because they need exactly the same resources.
• Plants might look peaceful, but they're in constant competition. Think about a forest floor where seedlings are trying to grow. They're all fighting for the same four things.
• Light is the big prize. Plants need it for photosynthesis, but tall trees cast shadows. That's why you see plants growing towards windows - they're literally reaching for the light.
• Space matters too. Roots need room to spread, and leaves need space to catch sunlight without being shaded by neighbours. Ever noticed how plants in a crowded garden bed grow tall and spindly? They're competing for space above ground.
• Water and mineral ions from the soil complete the list. Root systems spread out like underground networks, each trying to absorb as much as possible before their neighbours get there.
• Animals have different needs, so they compete for different resources. Watch any nature documentary and you'll see these three competitions playing out.
• Food is obvious - there's only so much prey to go around. Lions compete with hyenas for zebra carcasses. Garden birds compete for seeds at your bird feeder.

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.