adaptations

• what is an adaptation? What are the three types?

  characteristics on an organism that increase its chance of survival and reproduction.

  • anatomical- physical internal and external features
  • behavioural- actions
  • physiological- processes taking place within an organism

  adaptations can fall into more than one category, for example a behavioural and anatomical adaptation
• state examples of anatomical adaptations

  • camouflage
  • body covering
  • teeth
  • mimicry

  PLANTS- to minimise transpiration

  • curled/rolled leaves
  • hairs to trap moist air, minimising diffusion gradient
  • sunken stomata
  • thick waxy cuticle
• state examples of behavioural adaptations

  • survival behaviours
  • courtship
  • seasonal behaviours- migration and hibernation
• what two categories do behavioural adaptations fall into?

  • innate behaviours
  • learned behaviours
• examples of physiological adaptations?

  • poison production
  • antibiotic production- of bacteria to kill other bacteria species
  • water holding- holding water within an organism
  • reflexes
  • blinking
  • temperature regulation
• what is convergent evolution? what adaptation type provides evidence for convergent evolution?

  • takes place when unrelated species begin to share similar traits
  • takes place because organisms adapt to similar environments or other selection pressures, so begin living in a similar way to each other
  • anatomical adaptations provide evidence for this
• what is meant by selection pressure?

  factors affecting an organism's survival/reproductive success
• state the process of natural selection

  1. organisms begin showing genetic variation (new alleles rising by mutation)
  2. organisms best adapted to a selection pressure survive and reproduce, those who aren't fail to do so
  3. successful organisms pass the advantageous allele onto their offspring, organisms possessing non-advantageous allele less likely to pass it on
  4. process repeats over many generations, frequency of advantageous allele increases in gene pool
  5. over long time periods, many generations and the involvement of multiple genes, evolution of a new species emerges
• how does the evolution of pesticide resistance have implications for humans?

  • antibiotic/pesticide resistance eg MRSA- need to continue developing new antibiotics, using equipment to analyse DNA of these organisms, expensive, time consuming
  • pre-adaptations- when organism has existing adaptation for a new situation- makes it harder for humans to predict ways to prevent the spread of disease
  • can be used for economic/engineering benefit- produce useful enzymes/other useful substances/digest substances, etc