4.2: Practical: Investigate the Population Size of an Organism in Two Different Areas using Quadrats

QUADRATS: Rectangular frames of known dimensions that can be used to establish population densities by counting and identifying organisms within frame

MEASURING POPULATION OF ORGANISM:

ESTIMATING POPULATION SIZE OF ORGANISM

Diagram showing How Quadrats are Utilised in the Field

METHOD: Place quadrat randomly within sampling area Count the number of members of the same specieswithin the quadrat Repeat this numerous times within sampling area using the same size quadrat Repeat the process in another area to compare results

CALCULATION: Equation to Calculate the Approximate Population Size of an Organism:

4.1: Understand the Terms Population, Community, Habitat and Ecosystem

DEFINITIONS:

TERM	DEFINITION
POPULATION	All members of single species living in the same area at the same time
COMMUNITY	Groups of populations living and interacting with each other in an area
HABITAT	Environment in which species normally live in
ECOSYSTEM	Community and abiotic environment

4.5: Understand How Abiotic and Biotic Factors Affect the Population Size and Distribution of Organisms

ABIOTIC FACTORS: Non-living environmental factors that can affect organism in ecosystem

• Abiotic Factors can affect a range of Species as each organism is adapted to certain environments

EXAMPLES:

EXAMPLES
Light Intensity	Soil pH	Carbon Dioxide Levels
Soil Moisture Level	Availability of Minerals and Nutrients	Availability of Water
Temperature	Oxygen Levels

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BIOTIC FACTORS: Interactions between living organisms

• Biotic Factors will affect all Species as they have the vulnerability of being food to Predators or being a host to diseases that can affect Population of Species

EXAMPLES:

EXAMPLES
Grazing	Competition for Food	Fungi
Diseases	Competition for Shelter
Predation	Bacteria

4.4B: Practical: Investigate the Distribution of Organisms in their Habitats and Measure Biodiversity Using Quadrats

QUADRANTS: Square Made of Wires that is Divided into Smaller Areas in which Organisms underneath are Identified and Counted

QUADRATS: Rectangular frames of known dimensions that can be used to establish population densities by counting and identifying organisms within frame

MEASURING DISTRIBUTION AND BIODIVERSITY OF ORGANISM:

MEASURING DISTRIBUTION AND BIODIVERSITY OF ORGANISM

Diagram showing How Quadrats are Utilised in the Field

METHOD: Place quadrat randomly within sampling area Count the number of members of the same specieswithin the quadrat Repeat this numerous times within sampling area using the same size quadrat Repeat the process in another area to compare results Additionally, results can be shown on a map of sampled area, displaying which areas are densely populated by certain species and vice versa

INCREASING RELIABILITY OF RESULTS: Randomly place Quadrat Use Quadrat of same size with each repeat Take more samples to collect larger data size

4.3B: Understand the Term Biodiversity

BIODIVERSITY: Measure of the variety of different species living in a habitat (the greater number of different species in a habitat, the greater the biodiversity)

Example:

                    

Picture showing a Forest exhibiting biodiversity as it is home to numerous species of organisms