Biodiversity

Question 1

Biodiversity

Answer 1

The variety of life
The number of individual organisms and in how many places they can be found

Question 2

Habitat diversity

Answer 2

Number of different habitats

Question 3

Species diversity

Answer 3

Species evenness and species richness
Two habitats may have equal number of different species may not be considered as equally diverse

Question 4

Genetic diversity

Answer 4

The variation of alleles within a species

Question 5

Habitat

Answer 5

A place where individuals lives
E.g. woodland freshwater ponds hedgerows salt marsh meadow stream
The range of habitats = habitat biodiversity
Each habitat is occupied by a range of organisms

Question 6

Species

Answer 6

A group of individual organisms that are similar in appearance,anatomy,physiology,biochemistry and genetics
-They can interbreed to produce fertile offspring

Question 7

Similar species

Answer 7

Members of two fairly similar species can interbreed
A mule is a cross between a horse and a donkey
Offspring formed are sterile
Unable to produce their own offspring on reaching sexual maturity

Question 8

Genetic biodiversity

Answer 8

Variation between individuals of the same species that ensures we do not all look identical . Genetic variation can create breeds within a species

Question 9

Sampling biodiversity

Answer 9

Observe species present
I’d entity and count
Not possible for microorganisms in a habitat

Question 10

Why sample

Answer 10

We cannot know the total population but we can estimate from sampling
One issue is how representative the sample is of the target population
The more sample we take the closer we will be able to generalise to the population

Question 11

Sampling strategies

Answer 11

Random sampling
- uses coordinates,GPS, randomly selected ( frame/point quadrats) not biased - may miss key areas - underestimate biodiversity
Non random
- opportunistic - make descriptions based around prior knowledge of an area (biased) quick and easy
- stratified - dividing the habitat into different areas and sampling differently - may lead to over representation
- systematic - sampling at fixed intervals across the habitat (transects) useful where there is a gradient change , but other species not on the line may be missed

Question 12

Abiotic factors

Answer 12

• Non living
  Wind
  Water
  Sunlight
  Temperature
  Atmosphere

Question 13

Biotic factors

Question 14

Random sampling

Answer 14

• mark out the sample area and generate random coordinates to determine where the quadrant needs to be placed
• to avoid bias in your results, sample should be random
• abundance of a species can be measured in different ways

Question 15

Using a quadrat

Answer 15

• make a species list for each quadrat. Each species is either present or absent
• if a species is present, you can also record how much of there it is ie by estimating its percentage cover

Answer 16

1. Select an area to sample - a small geographical area within the habitat being studied
2. Lunt the number of individuals of each species
3. Repeat the process, taking a meaningful number of samples
4. Use the results to estimate the total number of individuals

Question 17

Measuring abundance

Answer 17

1. Frequency of occurrence - tick or cross if present on quadrat ( ignores density of species) SPECIES RICHNESS
2. Density of species - count each individual in the quadrat - time consuming if species are small e.g. grass
3. % cover - estimate area covered by a species - difficult when they overlap
4. Spabundance scales : simple but subjective : ACFOR scale
   (Abundance,common, frequent,occasional,rare)
   SAMPLE SIZE MUSY BE LARGE ENOUGH TO GET A RELIABLE ESTIMATE

Question 18

Estimating percentage frequency

Answer 18

Probability that a species will be found within a single quadrat
% frequency = number of quadrats in which the species is found/ total number of quadrats