Biodiversity, classification and evolution Flashcards
What is biodiversity?
Variety of living organisms in an area, can be measured in terms of species diversity, habitat diversity and genetic diversity
Differentiate between species richness and species evenness?
species richness = number of species in an area
species evenness = whether species have similar numbers
Discuss different types of sampling?
random =no particular system however aims to still be representative
opportunistic = those encountered first are chosen
stratified = population divided into smaller groups based on characteristics then sampled
systematic = follows a particular pattern
Why is sampling important?
We can’t study the whole population as it’s impractical, using a representative sample allows us to easily investigate the population
Describe how simpson’s index of diversity is used?
- measurement of the total number of organisms compared to the total number of organisms of each species
- high index of diversity means several different species are equally abundant
- low index means one or two species dominate others
How can we assess genetic diversity?
proportion of polymorphic gene loci = number of polymorphic gene loci ÷ total number of loci
Give factors that affect biodiversity?
- population growth
- deforestation for agriculture
- climate change affecting habitats
Give reasons to maintain biodiversity?
ecological = protecting species + maintaining resources
economic = reducing soil depletion
aesthetic = protecting landscapes
Define conservation?
Protection and management of species and habitats in order to maintain biodiversity
What are 2 types of conservation?
- in situ (in organisms habitat)
- ex situ (out of organisms habitat)
Give examples of in-situ conservation?
- marine conservation zones
- wildlife reserves
Give examples of ex-situ conservation?
- seed banks
- botanic gardens
- zoos
Give some agreements made with the aim of protecting species and habitats?
- conservation of international trade in endangered species (CITES)
- rio convention on biological diversity (CBD)
- countryside stewardship scheme (CSS)
Define classification?
Process of naming and organising organisms into groups based on their characteristics
Name the 8 groups in the classification hierarchy from largest to smallest?
- domain
- kingdom
- phylum
- class
- order
- family
- genus
- species
What are two components to a binomial name?
generic name = the genus the organism belongs too
specific name = the species the organism belongs too
What is the advantage of the binomial naming system?
It is universal, an organisms binomial name is the same everywhere in the world
Name the 5 kingdoms and 3 domains?
kingdoms:
- prokaryote
- protoctista
- fungi
- plantae
- anamalia
Domains:
- bacteria
- archaea
- eukaryota
How are organisms classified into a kingdom?
Based on similarities in observable characteristics
How the domain system of classification developed?
By analysing molecular differences between organisms to determine their evolutionary relationships (phylogeny)
What is the difference between classification and phylogeny?
- classification is simple sorting organisms into groups
- phylogeny investigates the evolutionary relationships between organisms
Explain how natural selection results in evolution?
- ransom mutations result in new alleles
- some alleles provide an advantage against selection pressures making an individual more likely to survive and reproduce
- their offspring receive the new allele and are said to have ‘evolved’ a new characteristic
How did Darwin and Wallace contribute to the theory of evolution?
- observed birds have many different beak shapes
- concluded birds with beak shapes most suited to the food they eat are more likely to survive
- therefore they pass their beak shape on to their offspring
Give other evidence for the theory of evolution?
fossils = allow us to compare extinct organisms to today’s organisms
genomic DNA = sequencing of genomes have shown how closely related we are to primates
molecular = proteins are composed of the same 20 amino acids in all organisms
What causes variation?
genetic = mutations, random fertalisation, etc
environmental = climate, diet, culture, etc
Differentiate between intraspecific and interspecific variation?
Intraspecific = variation within the same species
Interspecific = variation between different species
Differentiate between continuous and dis-continuous variation?
Continuous = variation exists as gradual changes over a range (e.g height + root length)
Dis-continuous = variation exists as distinct categories (e.g blood group + bacteria shape)
Why might we calculate a Spearman’s rank correlation coefficient?
To measure correlation between 2 variables, e.g the extent to which changing one variable affects the other variable
Explain how Spearman’s rank results are interpreted?
Closer to 1 = more positive correlation
Closer to -1 = more negative correlation
Around 0 = no correlation
What are 3 types of adaption and give an example of each?
- anatomical = changes to body structure (e.g oily fur)
- physiological = changes to bodily processes (e.g producing venom)
- behavioural = changes to actions (e.g hibernation)
Why might organisms from different taxonomic groups have similar features?
Marsupial moles and placental moles live in different continents, but share anatomical features because their adapted to similar environments
Give some implications of evolution for humans?
- bacterial antibiotic resistance means infections are harder to treat
- pesticide resistance means entire crops could be destroyed
