B10- Biodiversity Flashcards
What is a species?
A group of organisms that can (interbreed to) producefertile offspring
Suggest why 2 different species are unable to produce fertile offspring
Different species havedifferent chromosome numbers→offspring may haveodd chromosome number
Sohomologous pairscannot form→meiosiscannot occur to produce gametes
Explain why courtship behaviour is a necessary precursor to successful mating
- Allowsrecognitionof members ofsame species→sofertile offspringproduced
- Allows recognition / attraction ofopposite sex
- Stimulates /synchronises mating/ production / release of gametes
- Indicatessexual maturity/ fertility
- Establishes apair bondto raise young
Describe a phylogenetic classification system
- Species (attempted to be) arranged intogroups, calledtaxa, based on theirevolutionary origins(common ancestors) andrelationships
- Uses ahierarchy:
- Smaller groupsare placed within larger groups
- No overlapbetween groups
Name the taxa in the hierarchy of classification
Domain(largest / broadest)→kingdom→phylum→class→order→family→genus→species(smallest)
“Dear King Philip Came Over For Good Soup”
Suggest an advantage of binomial naming
Universalso noconfusionas many organisms have more than one common name.
How can phylogenetic trees be interpreted?
- Branch point =common ancestor
- Branch =evolutionarypath
- If two species have a more recent common ancestor, they aremore closely related(eg. C & D)
Describe two advances that have helped to clarify evolutionary relationships between organisms
- Advances ingenome sequencing→allowing comparison of DNA base sequences
● Moredifferencesin DNA base sequences→more distantly related/earlier common ancestor
● Asmutations(change in DNA base sequences)build up over time- Advances inimmunology→allowing comparison ofprotein tertiary structure(eg. albumin)
● Higher amountof protein from one speciesbindstoantibodyagainst the same protein from
another species→more closely related/more recent common ancestor
● As indicates a similaramino acid sequenceandtertiary structure
● So less time formutationsto build up
- Advances inimmunology→allowing comparison ofprotein tertiary structure(eg. albumin)
What is biodiversity?
- Varietyof living organisms (species, genetic and ecosystem diversity)
- Can relate to a range ofhabitats, from a smalllocalhabitat to theEarth
What is a community?
Allpopulationsof different species that live in an area.
What is species richness?
A measure of thenumberofdifferent speciesin acommunity
What does an index of diversity do?
- Thenumber of species in a community (species richness)
- The number ofindividuals in each species(population size)
Suggest why index of diversity is more useful than species richness
- Also takes into accountnumber of individuals in each species
- So takes into account that some species may be present insmallorhigh numbers
Removal ofwoodlandandhedgerows
- Reducesvariety of plants
- So fewerhabitatsand niches
- And lessvariety of food sources
Use ofpesticidesto kill pests
Predatorpopulation of pest decreases
Explain the balance between conservation and farming
- Conservation required toincrease biodiversity
- But when implemented on farms,yieldscan be reduced, reducingprofit/incomefor farmers
- ○Eg. by reducing land area for crop growth, increasing competition, increasing pest population
- To offset loss,financial incentives / grantsare offered
Give examples of how biodiversity can be increased in areas of agriculture
- Reintroduction offield marginsandhedgerows(where farmers only grow one type of crop)
- Reduce use ofpesticides
- Growingdifferent cropsin the same area (intercropping)
- Usingcrop rotationof nitrogen fixing crops instead of fertilisers
