Biodiversity :). Flashcards
What is a species?
A group of similar organisms able to reproduce to give fertile offspring
What is a habitat?
The area inhabited by a species which includes physical factors and living biotic factors
Name 1 physical factors of a habitat
Soil and temperature range
Name 2 living biotic factor?
Availability of food
Presence of predators
What are areas high biodiversity?
Areas with lots of different species
What is habitat diversity?
Number of different habitats in an area
e.g. Particular area could contain many different habitats- sand dunes, woodland, meadows, streams etc.
What is species biodiversity?
The number of different species and abundance of each species in an area.
E.g. Woodland could contain many different species of plants, insects, birds and mammals.
What is genetic diversity?
The variation of alleles within a species or population of a species
E.g. Variation of alleles within dog species give rise to different breeds e.g. Labrador or poodle
Species richness is?
Number of different species in an area, the higher the number of species the greater the species richness
What is species evenness?
Measure of relative abundance of each species in an area. The more similar the population size of each species the greater the species evenness
How is species richness measured?
Measured by taking random samples of a habitat and counting the number of different species
What is species evenness measured?
By taking random samples of a habitat and counting the number of individuals of each different species
What is biodiversity?
The variety of living organisms in an area
Why is a sample taken?
In most cases it would be too time consuming to count every individual organism in a habitat
What are based upon the sample taken?
Estimates about the whole habitat
What does sampling usually involve? (4 stages)
1)Choose area to sample
Count number of 2)individuals of each species
3) repeat process
4) use results to estimate total number of individuals
When comparing different habitats and comparing them what must you do?
Use the same sampling technique
What sort of area would you choose to sample?
A small area within the habitat being studied
How would you count number of individuals plants?
Use quadrat
How would you count number of individual flying insects?
A sweep net
Net on pole
How would you count number of individual ground insects?
Use pitfall trap
Small trap that insects can’t get out of
How would you count number of individual aquatic animals ?
Use net
How many samples should you take and why?
As many as possible as will give better indication of the whole habitat
For step four what is the other option to estimating total number of individuals?
Total number of different species in the habitat being studied
How could you investigate impact of mowing on biodiversity of school playing field?
Sample mowed and un-mowed field
Calculate biodiversity for each field using Simpsons index
Why should samples be random?
To avoid bias
How could you select a random sample for plant species in a field?
Dividing forks into grid using measuring tape using random number generator to select coordinates
Can random samples always be taken?
No sometimes it’s necessary to take non-random sample
Give a example of when a non-random sample would need to taken?
Lot of variety in distribution of species in the habitat and you want to make sure all different areas are sampled
Name the three types of non-random sampling?
Systemic
Opportunistic
Stratified
Explain systemic sampling?
When samples taken at fixed intervals often along a line
Give example of systemic sampling?
Quadrats could be placed along a line (transect) from area of shade in the corner to the middle of a field
Explain opportunistic sampling?
When samples are chosen by investigator used because it is simple to carry out but data will be biased
Stratified explain?
When different areas in habitat identified and sampled in proportion to part of habitat as whole
Give stratified sampling example
Heathland may have patches of gorse in it
Heath and gorse areas would be samples separately according to how much of each there was in the habitat
How shouldn’t a species present in a small number be treated the same as?
Those with bigger populations
What two things does the Simpson’s index take into account?
Species richness and species evenness
What is the formula for the Simpsons index of diversity?
D= 1-(Σ(n/N)^2)
What do the letters mean in the Simpsons index formula?
D= Simpson’s index of diversity
n= total number of individuals of one species
N=total number of organisms of all species
What is the range that the Simpsons index of diversity can take?
Between 0 and 1
What does the Simpsons index of diversity mean the close to 1 the index is?
The more diverse the habitat
What causes the Simpsons index of diversity to get close to one?
The greater the species richness and evenness, the higher the number
What are genetic resources?
Any material from plants, animals or microorganisms containing genes that we find valuable
What could genetic resources be?
Crops
Plants used for medicine
Microorganisms used in industrial processes
Animal breeds
Give two reasons why maintaining genetic resources is vital?
1) Genetic resources provide us with a variety of everyday products
2) genetic resources all us to adapt to changes in the environment
Genetic resources provide us with a variety of everyday products. Give examples
Food and drink Clothing Drugs Field Other industrial materials
Explain genetic resources relevance to food and drink
Plant and animals are sources of all good and some drink
Explain genetic resources relevance to clothing?
Lot of fibres and fabrics made from plants and animals
E.g cotton from plants
Leather from animals
Explain genetic resources relevance to drugs?
Many are made from plant compounds
E.g. Morphines painkiller made from poppy seeds
Explain genetic resources relevance to fuels?
Number of organisms produce renewable fuels e.g ethanol and biogas
Fossil fuels non-renewable so run out so other sources are of renewable economic importance
Explain genetic resources relevance to other industrial material?
Huge variety of other materials produced from plant and animals species e.g. Wood, paper, dyes, adhesives, oils, rubber and chemicals like pesticides
What is genetic diversity?
The variation of alleles within a species or within a population of a species
How is genetic diversity of a population worked out?
Using calculations
How does it matter if a population has low genetic diversity?
They might not be able to adapt to change in the environment and the whole population could be wiped out by a single event e.g. A disease
Name some populations that may have low genetic diversity?
Isolated populations
Those bred in captivity e.g. Zoos, pedigree animals, rare breeds…
What can the calculations if genetic diversity monitor?
Genetic diversity of the populations over time
What can be done if genetic diversity is low?
Efforts can be made to increase genetic diversity of population if needed.
E.g. Breeding programmes in zoos closely managed to maximise genetic diversity
What are alleles?
Different versions of a gene
Where on the chromosome are alleles of the same gene found?
At the same point (locus) is
What does polymorphism describe?
Locus that has two or more alleles
Working out what gives a measure of genetic diversity?
Proportion of polymorphic gene loci in an organism
Those points on chromosomes can have more than one alleles
Formula for proportion of polymorphic genetic loci=
(Number of polymorphic gene loci)/(total number of loci)
How do you get percentage of genes in sample that have alleles?
Polymorphic gene loci x100
Three factors affecting global biodiversity?
Human population growth
Increased use of monoculture in agriculture
Climate change