Classification and biodiversity Flashcards
Distinguish between analogous and homologous structures and explain why analogous features are not considered evidence of common ancestry (3)
- analogous structures are different structures that perform a similar function
- homologous structures are similar sructures performing different functions
- analogous structures arise through convergent evolution
What does the ‘tentative nature’ of classification mean (2)
- classification may change
- as more information becomes available
Name a biological technique to confirm that organims are seperate species (1)
DNA hybridisation
Explain how the results of Dna profiling tests have been udes to determine that these two species were most closley related (1)
- they would have more sequences in common
State one characterisitic which is common to all vertebrates (1)
- possess internal skeleton
- backbone
Explain why sampling should be conucted at random (1)
to eliminate sampling bias
Explain what precautions must be observed during collection of terrestrial animal population (2)
- make sure that not of the animals are hurt or make them visible to predators
- not allowed animals to reintegrate into the population - 24hrs
Describe one assumption that has to be made when using the results when collecting terrestrial animal population (1)
- no births
- no deaths
- no immigration or emmigration has occured between collecting samples
State two variable which should bet controlled in a quadrat experiment (2)
- choose fields of similar size
- quadrats randomly placed to avoid bias
- similar abiotic factors ed moisture, light
Explain in confidence in the conclusion could be improved when uing quadrats (2)
- increase number of quadrats used
- repeat experiment with other fields
suggest why do farmers are encouraged to let fields lie fallow for several years (1)
species diversity increases when left to lie fallow
Explain why limbs provide evidence for divergen evolution (1)
Evidence where structure has evolved from a common ancestor to perform a different function
Using examples explain how natural selection has led to anatomical, physiological and behavioural adaptations in mammals (9)
- Darwin recognised that species changed
- Proposing the theory of natural selection to explain why it happened
- organisms overproduce offspring
- so that there is a large varaition of genotypes in population
- changes to environemental conditions bring new selection pressures through competition, predation / diseases
- only those individuals with beneficial alleles conferring a beneficial phenotype have a selective advantage eg white fur in arctic therefore are more likely to survive
- thee individuals then reproduce
- offspring are likely to inherit the beneficial alleles
- therefore the beneficial allele frequency increases with the gene pool
Adaptations any good example so long as each type covered with advantages: - anatomical - beak shape in finches able to exploit different food
- Physiological - haemoglobin with higher affinity for oxygen allowing llamas to live at high altitude
- behaviourals - nocturnal animals avoiding heat of the day
What kingdom does these features contain : heterotrophic eukaryotes , cell wall of chitin, reproduce by spores (1)
fungi
What kingdom does these features contain : Heterotrophic , multicellular eukaryotes , no cell wall , nervous coordination (1)
Animalia