OCR A LEVEL BIOLOGY EXAM SCRIPT 2026
FULL SOLUTION TEST BANK
●● how does random sampling work. Answer: random number tables or
computers are used - mark out a grid using two tape measures laid at
right angles, use random numbers to generate the x and y coordinate on
your grid, take a sample at each of the coordinate pairs measured
●● measuring biodiversity. Answer: habitat biodiversity, species
biodiversity, genetic biodiversity
●● habitat biodiversity. Answer: the number of different habitats found
within an area (greater habitat biodiversity, greater species biodiversity)
●● species biodiversity. Answer: species richness and species evenness
●● non-random sampling. Answer: an alternative sampling method to
random sampling, where the sample is not chosen at random. It can be
opportunistic, stratified or systematic.
●● sampling. Answer: taking measurements of a limited number of
individual organisms present in a particular area
, ●● abundance of organisms. Answer: number of individuals of a species
present in an area
●● sampling uses. Answer: can estimate abundance (without having to
count them all) and can measure a particular characteristic (mean height
of plants for example)
●● opportunistic sampling. Answer: sampling using the organisms that
are conveniently available. The weakest form of sampling as it may not
be representative of the population.
●● stratified sampling. Answer: sampling where populations are divided
into sub-groups (strata) based on a particular characteristic. A random
sample is then taken from each of these strata proportional to its size.
●● systematic sampling. Answer: different areas of a habitat are
identified and sampled separately. Often carried out using a line or belt
transect.
●● line transect. Answer: Marking a line along the ground between
points and taking samples at specific points
●● belt transect. Answer: two parallel lines are marked along the ground
and samples are taken of the area
at specified points.
FULL SOLUTION TEST BANK
●● how does random sampling work. Answer: random number tables or
computers are used - mark out a grid using two tape measures laid at
right angles, use random numbers to generate the x and y coordinate on
your grid, take a sample at each of the coordinate pairs measured
●● measuring biodiversity. Answer: habitat biodiversity, species
biodiversity, genetic biodiversity
●● habitat biodiversity. Answer: the number of different habitats found
within an area (greater habitat biodiversity, greater species biodiversity)
●● species biodiversity. Answer: species richness and species evenness
●● non-random sampling. Answer: an alternative sampling method to
random sampling, where the sample is not chosen at random. It can be
opportunistic, stratified or systematic.
●● sampling. Answer: taking measurements of a limited number of
individual organisms present in a particular area
, ●● abundance of organisms. Answer: number of individuals of a species
present in an area
●● sampling uses. Answer: can estimate abundance (without having to
count them all) and can measure a particular characteristic (mean height
of plants for example)
●● opportunistic sampling. Answer: sampling using the organisms that
are conveniently available. The weakest form of sampling as it may not
be representative of the population.
●● stratified sampling. Answer: sampling where populations are divided
into sub-groups (strata) based on a particular characteristic. A random
sample is then taken from each of these strata proportional to its size.
●● systematic sampling. Answer: different areas of a habitat are
identified and sampled separately. Often carried out using a line or belt
transect.
●● line transect. Answer: Marking a line along the ground between
points and taking samples at specific points
●● belt transect. Answer: two parallel lines are marked along the ground
and samples are taken of the area
at specified points.
