Sampling OCR A Level Biology

Flashcards covering various sampling categories including random and non-random techniques, animal capture methods, and plant sampling using quadrats and transects.

Random Sampling

A sampling method designed to avoid bias by using a grid marked with tape measures and random numbers to generate $x$ and $y$ coordinates for sample locations.

Systematic Sampling

A non-random sampling method where different areas of one habitat are sampled separately, often using transects.

Stratified Sampling

A sampling technique where populations are divided into strata based on a specific characteristic, such as male and female.

Opportunistic Sampling

A non-random sampling method that uses organisms that are conveniently available; it is noted as not being representative of the whole population.

Line Transect

A systematic sampling tool where a line is drawn between two poles and samples are taken at specified points along that line.

Belt Transect

A systematic sampling method where two parallel lines are marked and samples are taken from the area between them.

Pooter

An animal sampling tool used to collect organisms.

Sweep net

An animal sampling tool used to capture organisms by sweeping through vegetation.

Pitfall traps

A sampling tool used to capture animals that fall into a trap set in the ground.

Tree beating

A method or tool listed for sampling animals from trees.

Kick sampling

An animal sampling technique typically used in aquatic or ground environments.

Capture-Mark-Release-Recapture

A four-step animal sampling process: 1. Capture individuals, 2. Mark them, 3. Release them, 4. Recapture individuals to compare marked ($M$) versus unmarked ($U$) to calculate population size.

Point Quadrat

A plant sampling tool consisting of a frame with a horizontal bar where a long pin is inserted; each plant touched by the pin is recorded.

Frame Quadrat

A plant sampling tool where the type and number of species in each section of the quadrat are recorded.

Density

An absolute measure used in plant sampling for large plants, often measured per $m^2$.

Frequency

A plant sampling estimate used for grass or moss, calculated as: $\frac{\text{number of squares with species}}{\text{total number of squares}}$.

Cover

A rough estimate used in plant sampling for abundant species, calculated as: $\frac{\text{number of squares with species}}{\text{total number of squares}}$.