Topic 4 - Diversity And Classification Flashcards
Population
All the organisms of one species in a habitat
Community
All of the population of all species in a habitat
Biodiversity
The variety of a species in an area
Species richness
The number of different species in an area
Index of diversity
Describes the relationship between number of species in a community and the number of individuals of each species
Species
Organisms are the same species if the can breed to produce fertile offspring
Index of diversity calculation
d=Nx(N-1)/sum of nx(n-1)
N = total number of organisms of all species
n = total number organisms of each species
Effects of farming on biodiversity
Decreases biodiversity:
Forests are cleared
Hedgerows are removed
Monocultures (fewer species of plants, fewer species of insects, fewer food sources for other species, fewer habitats and niches)
decreases the genetic variety of alleles (farmers control for particular characteristics)
use of pesticides
decreases the index of species diversity
Conservation
Get farmers to conserve biodiversity
Protect species by law
Restrict urban development in important biodiverse areas
Intraspecific
Comparing genetic diversity within a species
Interspecific
Comparing genetic diversity between species
Causes of diversity/variation
Genetic differences such as blood type
Environment differences such as nutrition
How to maintain biodiversity/ conservation
Use hedgerows instead of fences
Intercropping (growing different crops in the same area)
Reduce the use of herbicides and pesticides
Preserving wetlands instead of draining
plant native trees on land with low species diversity
use crop rotations that include nitrogen fixing crops
create natural meadows
conservation of headlands (areas around the edge of the fields)
leave the cutting of verges until after seed dispersal
Causes of reduction in species diversity
Habitat destruction, invasive species, climate change, pollution, pesticides and fertilisers, human overpopulation, deforestation, hedgerows removed, monocultures are created
Species diversity
The number of species in a community
Directional selection
Caused by a change in environmental conditions
Extreme characteristics survive and reproduce
Only those with the allele will survive (graph moves in the direction of these individuals
Stabilising selection
Individuals with extreme characteristics are less likely to survive and reproduce
The mean stays the same as the most likely to survive are in the middle range
phenotypes close to the mean survive
stable conditions
Evolution
Variation of alleles exist in a population
Result of mutation
Selection of individuals with beneficial allele
Differential reproductive success
Changes allele frequency
Occurs over a long period of time
Natural selection adaptions
Anatomical - changes to your anatomy eg giraffes long necks
Physiological - eg shivering
Behavioural - changes to the way you behave eg becoming nocturnal
genetic diversity
the number of different alleles of a gene in a population
natural selection
individuals of population that are best suited to their environment survive and reproduce more.
the beneficial alleles are the most likely to pass onto the next generation
evolution (definition)
change in allele frequency over time
Sampling large sample of a population
The data should be representative of the whole population (use a statistical test)
How to compare genetic diversity
Comparing DNA sequence, mRNA sequence, amino acid sequence
Observe characteristics and put into groups
Phylogenetic classification
Arraigning species into groups based on evolutionary relatedness
Standard deviation
The average variation of the data away from the mean
Lower the standard deviation the more reliable
Bars of siginficance
Dot overlap they ARE significantly different
Overlap they are NOT significantly different
Courtship behaviour
Increases the chance of successful mailing because > recognition of same species > stimulates the release of gametes > recognises the opposite sex/gender > indicate sexual maturity
Hierarchy classification
Domain Kingdom Phylum Class Order Family Genus Species
Phylogenetic - genome sequencing
Compare the order of base sequences on genome of different species
Higher % match = more closely related
phylogenetics Immunology
DNA - mRNA - amino acid - proteins
3 of protein tells us about sequence of DNA
If same antibodies bind to a specific antigen then it is closely related
Binomial names
Method of giving each species a name consisting of two words
First - name of the genus
Second - species
- Genus is written with a capital letter but no capital letter on the species
- both are underlined or in italics
Eg Homo sapiens
What are phylogenetics
Small groups within a big group
No overlap between groups
Taxon
A level in hierarchy
Molecular phylogeny
The analysis of molecular differences in different organisms to determine the extent of their evolutionary relatedness
Limits to using observable characteristics to classify species
Characteristics can be coded for by more than one gene
Same characteristics could have arisen separately
Characteristics can be influenced by the environment and not the gene
genetic diversity
the number of different alleles of genes in a population
- the greater the number of different alleles the greater the genetic diversity - the more likely some individuals of the population will survive
- wider range of alleles the wider range of characteristics
- greater diversity enable natural selection
natural selection in evolution
- gene pool in a population containing a wide variety of alleles
- random mutations can result in new alleles - some are harmful but some are advantageous in certain environments
- new allele individuals are better adapted so are more likely to survive in competition
- individuals will live longer and grow more so have a higher chance of breeding and having more offspring
- advantageous allele is passed on to next generation
- offspring with advantageous are more likely to survive and reproduce
- number of individuals with advantageous allele increases
- non advantageous decreases
directional selection - antibiotic resistance
- effectiveness of antibiotics decreased
- spontaneous mutation on the allele of the gene in a bacterium, creating a new protein
- new protein broke down the antibiotic penicillin before it could kill the bacterium
- bacterium happened to be in a situation where penicillin was being used to treat an individual
- these circumstances gave the bacterium an advantage to use penicillinase to break down the antibiotic
- bacterium divided by binary fission
- penicillin resistant population could survive more than non-resistant
- resistant population increased so increasing frequency of allele that enabled production of penicillinase to increase in the population
- normal distribution curve shifted to the greater resistance
stabilising selection - human birth weights
- body mass at birth of babies was measured and at the same time infant mortality rate was also recorded
- body mass and infant mortality rate were plotted against each other
- steep line increase where mass is low and high
- so there is a greater risk of infant mortality when the birth weight is outside of the range/ mean
