biodiversity

Question 1

what are some economic reasons for maintaining biodiveristy

Answer 1

• organisms can provide valuable ecosystem services eg. cleaning water and pollination of crops which reduces money spent on doing this artificially
• areas rich in biodiversity attract tourists which provides job opportunities.
• some plants are a source of medicines eg. digitalis origionated from foxglove which are sold on a global scale
• genetic recourses are useful and allow us to adapt to changes
  eg. alleles in a plant for drought resistence can be isolated and used to genetically engineer a drought resistent crop.

Question 2

what are some ecological reasons for maintaining biodiversity

Answer 2

• preserving existence of keystone species is important, if they were to go extinct this would have a large impact on ecosystem and food chains.

maintain a global gene pool - invaluable genetic recourse, vital in species so they can evolve and adapt to new predators, diseases and environmental changes. eg. alleles for disease resistance

Question 3

what is monoculture, what are some disadvantages of monoculture

Answer 3

the production of a single species of plant.

In monoculture, plants are often genetically identical. This can therefore result in an ideal situation for pests, weeds and plant diseases to emerge. If they can outcompete or affect one plant, they can do so for all the other identical plants.

+ depletes the soil of particular mineral ions

Question 4

what are the 2 types of conservation

Answer 4

in situ - protecting species in their natural habitat

ex situ - removing part of the population from threatened habitat and placing in new location. Eg zoo’s

Question 5

what are the 4 types of variation

Answer 5

intraspecific - variation within same species

interspecific - variation between different species

continuous variation - when individuals in a population vary within a range. No distinct categories eg. height, mass, width

discontinuous variation - two or more distinct categories, each individual fits into only one category, no overlap

Question 6

how is continuous data represented

Answer 6

line graphs and histograms.

Question 7

how is disconintuous data represented

Answer 7

bar chart

Question 8

what is the cause of variation

Answer 8

different species have different genes

individuals of the same species have the same genes but different alleles. Alleles code for genotype, differences in genotype result in variation of phenotype.

environmental factors such as climate and food can cause variation

genetics determines the characteristics an organism is born with, but environmental factors can influence how these characteristics develop

Question 9

what causes genetic variation

Answer 9

• mutation
• random mating between organisms
• random fertilization
• crossing over (or recombination) between chromatids of homologous chromosomes during meiosis

Question 10

why is genetic variation/diversity important

Answer 10

Genetic variation is essential for natural selection because natural selection can only increase or decrease frequency of alleles that already exist in the population.

Genetic variation is advantageous to a population because it enables some individuals to adapt to the environment while maintaining the survival of the population.

Question 11

what is genetic diversity

Answer 11

how many genes and gene pools there are in a population. Looks at the number of loci and compares to the number of alleles.

For example, a population with many different alleles at a single chromosome locus has a high amount of genetic variation

Question 12

what are the 3 types of diversity

Answer 12

habitat diversity

species diversity - species richness and species evenness

genetic diversity - variation of alleles within a population of a species

Question 13

what is biodiversity

Answer 13

the variety of living organisms in an area

Question 14

what are the 4 types of sampling that can be done to assess biodiversity

Answer 14

random
opportunistic
stratified
systematic

Question 15

what is random sampling

Answer 15

dividing area into grid using measuring tapes,
uses a random number generator for co-ordinates
placing a quadrat at those co-ordinates and sampling abundance

Question 16

what is a strength and limitation of random sampling

Answer 16

strength - avoids bias
limitation - may underestimate diversity if not all areas/types of habitat are sampled therefore data may not be representative

Question 17

what is stratified sampling

Answer 17

dividing up the area into distinct zones/habitats then sampling the area according to the ratio of areas.

Question 18

what is a strength of stratified sampling

Answer 18

ensures all areas are sampled so prevents small populations from being missed out

allows areas of different population levels in the same habitat to be sampled equally

Question 19

what is a limitation of stratified sampling

Answer 19

may lead to over-representation of some areas, for example small areas may be sampled more than necessary because they look different from other areas.

Question 20

what is opportunistic sampling

Answer 20

areas are chosen to be sampled based on prior knowledge of the habitat or choosing areas that are of interest.

Question 21

what is a strength and limitation of opportunistic sampling

Answer 21

easier and quicker

subject to bias, for example species that are more noticable may be sampled more than unnoticable species leading to an inaccurate estimate of biodiversity

Question 22

what is sytematic sampling

Answer 22

samples are taken at set regular intervals along the transect

Question 23

what is a strength and limitation of systematic sampling

Answer 23

this is useful to view a change in biodiversity or populations along a distance

method has the risk of missing species as only a small area is sampled, could result in underestimation of diversity.

Question 24

what is species richness

Answer 24

number of different species in an area

Question 25

what is species eveness

Answer 25

measure of the relative abundance of each species in an area

Question 26

how is genetic diversity maintained in zoos

Answer 26

breeding programmes are managed to increase GD
databases are kept up to date and it is decided which animals should be paired for breeding and these animals can be transferred between zoos. this reduces interbreeding.

Question 27

what is polymorphism

Answer 27

described a loci (position on a gene) that contains 2 or more alleles.

Question 28

how can genetic diversity be calculated

Answer 28

by assessing the proportion of polymorphic. gene loci in a population

prop. of polymorphic loci = no. of polymorphic loci / total number of loci

Question 29

what might in situ conservation involve

Answer 29

establishing protected areas, creating national parks and restricting urban development.

controlling/preventing introduction of species that threaten local biodiversity.

protecting habitats, controlling water levels, trimming trees, restoring damaged areas

Question 30

what are some strengths and limtations of in situ conservation

Answer 30

conserves the species and their natural habitat, less disruptive to the species and allows larger populations to be protected.

however cannot control all factors such as climate change and predators

Question 31

what might ex situ conservation involve

Answer 31

relocating a number of the population to a different area.

breeding programmes and release into wild

botanic gardens - seeds. can be frozen and stored their fertility is maintained - useful if natural reserves are destroyed.

Question 32

what are some strengths and limitations of ex situ conservation

Answer 32

protects individual animals in a controlled environment, allowing predation and hunting to be more easily controlled. Competition for recourses can be controlled and is easy to check on health and treat diseases
breeding can be manipulated

• only a small number of population can be. cared for
  difficult and expensive to sustain right environment conditions
  animals used to human contact more likley to catch disease
  some species do not adapt to new environment

Question 33

what is a keystone species

Answer 33

one that has a profound effect on the ecosystem in which they live, especially on the other trophic levels. Keystone species play such a vital role in ecosystems that the entire ecosystem may collapse in their absence. Many, but not all, keystone species are apex predators.

Question 34

what was the aim of the rio convention on biological diversity and what was the result

Answer 34

was an international agreement that aimed to develop international strategies on conservation of biodiversity and how to use recourses in a sustainable way.

resulted in international laws that recognised conserving biodiveristy is everyone’s responsibility.

Question 35

what was the aim of the CITES agreement and what was the outcome

Answer 35

aimed to increase international cooperation in regulating trade of wild animals and plant species.

made it illegal to trade in products made from endangered species

Question 36

what was the aim of the countryside stewardship scheme and what was the outcome

Answer 36

aimed to conserve wildlife and biodiver and to improve and expand habitats by promoting specific managment techniques to land owners.

Government offered 10 year agreement to pay farmers who followed managment techniques such as regenerating hedgerows.