Edexcel A Level (IAL) Biology -4.19 Ecological Niches & Adaptations- Study Notes- New Syllabus
Edexcel A Level (IAL) Biology -4.19 Ecological Niches & Adaptations- Study Notes- New syllabus
Edexcel A Level (IAL) Biology -4.19 Ecological Niches & Adaptations- Study Notes -Edexcel A level Biology – per latest Syllabus.
Key Concepts:
- 4.19 understand the concept of niche and be able to discuss examples of adaptations of organisms to their environment (behavioural, anatomical and physiological)
Ecological Niche & Adaptations of Organisms
🌱 Introduction
Every organism has a special role in its environment like its own “job” or “address” in nature. This role is called its niche. How well an organism survives depends on how perfectly it is adapted to its niche.
🧬 What is a Niche?
Definition:
A niche is the role and position a species has in its ecosystem how it meets its needs for food, shelter, and reproduction, and how it interacts with other organisms and the environment.
In short:
“A niche describes where an organism lives and what it does there.”
Example:
The oak tree → provides shade, food, and habitat → supports many other species.
The woodpecker → niche = tree trunk dweller that feeds on insects under bark.
Note:
No two species can occupy exactly the same niche in the same habitat this is the competitive exclusion principle.
🧩 Types of Adaptations
Organisms evolve special features called adaptations to survive successfully in their niches. These can be behavioural, anatomical, or physiological.
🧠 Behavioural Adaptations
Actions or habits that help an organism survive.
| Example | Explanation |
|---|---|
| Penguins huddle together | Conserves heat in extreme cold |
| Nocturnal animals (e.g. owls) | Avoid daytime predators and heat |
| Migration in birds | Move to favourable climates or breeding sites |
Behavioural adaptations are learned or instinctive and help with feeding, mating, or avoiding predators.
🦴 Anatomical (Structural) Adaptations
Physical features or structures that improve survival.
| Example | Adaptation Function |
|---|---|
| Thick fur and fat layer in polar bears | Insulation in cold Arctic |
| Webbed feet in ducks | Efficient swimming |
| Long neck of giraffe | Access to high leaves in trees |
| Cactus spines | Reduce water loss, protect from herbivores |
These are visible features shaped by evolution to fit the environment.
🔥 Physiological Adaptations
Internal body processes that enhance survival.
| Example | Function |
|---|---|
| Concentrated urine in desert animals | Conserves water |
| Antifreeze proteins in Arctic fish | Prevents ice crystal formation in blood |
| Photosynthetic efficiency in desert plants (CAM cycle) | Saves water by fixing CO₂ at night |
| Snake venom production | Helps capture prey and defense |
These adaptations are biochemical or metabolic and not visible externally.
🌿 Summary Table
| Type of Adaptation | Description | Example |
|---|---|---|
| Behavioural | Actions aiding survival | Migration, huddling |
| Anatomical | Body structure aiding survival | Thick fur, long neck |
| Physiological | Internal processes aiding survival | Antifreeze proteins, CAM photosynthesis |
🌎 Niche + Adaptation Connection
- The niche determines the kind of adaptations an organism evolves.
- Organisms with similar niches often show convergent adaptations (e.g., shark and dolphin body shapes).
- Successful adaptation = better survival and reproduction.
⚡ Quick Recap
Niche = “role” of an organism in its environment.
No two species share the same niche (competition).
Behavioural, Anatomical, Physiological = 3 types of adaptations.
Adaptations help organisms survive, reproduce, and maintain ecological balance.