Biodiversity Flashcards
(16 cards)
What is the definition of classification?
Organisation of living organisms into groups
What is the definition of a species?
A group of organisms of common ancestry that closely resemble each other, and are capable of interbreeding to produce living, fertile offspring
What is the system of classification we use and who devised it?
The Linnaeus system of classification
Carl Linnaeus
What are 2 features of the Linnaeus system of classification?
It is hierarchical - features organisms arranged into large groups then smaller and smaller groups
There is no overlapping between groups
How does the Linnaeus system benefit biologists?
(5 points)
- Aids in communication and education
- Helps identify evolutionary links between species
- Each organism has a unique name so communication between languages is unambiguous
- Stops confusion if an organism has multiple names
- Allows us to make generalisations about organisms and predict characteristics
Why is there difficulties in defining a species?
(5 points)
- Species are not fixed, they change and evolve over time
- Considerable variation within species exists
- Many species are extinct and no records exist
- Some rarely reproduce sexually
- Some species are sterile
What does courtship enable individuals to do?
(4 points)
- Recognise a member of the same species
- Identify a mate that is capable of breeding
- Form a pair bond
- Synchronisation of mating
How does deforestation affect diversity?
Reduces the number of species that can exist in the same are so reduces diversity
What happens to alleles and gene pools in monoculture?
- Specific alleles of specific species are deemed the best
- The farmer selects these alleles and all else is suppressed to maximise biomass
What happens to all other species when monoculture has taken place?
Species struggle and gene pools shrink, resulting in low species diversity
How does agriculture affect diversity? (4 steps)
- Farmers select a species with a desired characteristic, decreasing genetic diversity
- One area can only support a certain amount of biomass, so the number of species that can occupy one area is also reduced as it is filled with the desired species
- This increases the competition for resources so other species die out
- Use of pesticides also remove diversity
How does the removal of hedgerows affect diversity?
- Removes breeding areas for birds
- Insect species lose habitat
- Disrupts food webs
- Loss of shelter from air movements
- Reduction in diversity of animals
What is the balance between conservation and farming? (explain)
Balance between providing food for humans and retaining habitats to keep diversity high
What are measures the farmers use that directly affect biodiversity? (4 points)
- Removal of hedgerows and woodland
- Creating monocultures
- Filling in ponds and draining marshland
- Overgrazing land by sheep/cattle
What are measures that farmers use that indirectly affect biodiversity?
- Use of pesticides and inorganic fertilisers
- Escape of effluent into waterways
- No crop rotation and lack of intercropping
What are 5 conservation techniques farmers could use to reduce the loss of/maintain biodiversity?
- Plant hedges rather than fences
- Leave wet fields and don’t dry them
- Plant native trees when species diversity is low
- Use crop rotation including a nitrogen fixing crop rather than fertilisers
- Reduce the use of pesticides or use GM organisms that are pest resistant
