P2

• suggest 2 ways to improve the students' method for measuring human reaction time

  1. find the mean
  2. make sure 0cm line is held above the thumb
• whhich scientists suggested the theory od evolution by natural selection

  alfred wallace and charles darwin
• what substances can the sundew plant make using the phosphates

  dna
• what substance can the sundew plant make using the nitrogen

  protien
• one way to imporve how students can investigate the number of tadpoles in a pond for 8 weeks

  collect more pond water so increase the sample size. this will make it more representative of the pond
• describe 2 efets of adrealine on the human body

  • incrceases heart rate
  • increases breathing rate
• what is a dominant allele

  allele that is always present
• suggest 2 reasons why some people are concerned about the use of GM soya bean plants. do not refer to ethical concerns

  • could taste dfferent
  • unknown effects of animals and humans (when eaten)
• label the components of a section of DNA strand (diagram)

  circle- phosphate

  rectangle- base

  pentagon- sugar
• explain why studying and sequencing the human genome is important for the medical science and healthcare [4]

  • allows to understand human evolution and variation
  • helps identify genetic diseases/ disorders
  • allows early diagnosis of genetic conditions
  • can help predict the effectiveness of a drug
• which hormone is responsible fo increasing blood glucose levels

  glucagon
• explain how the hormones insulin and glucagon regulate blood glucose conc after a meal [5]

  • blood glucose increases so pancreas detects and secretes insulin
  • insulin enters cells and causes glucose to convert to glycogen
  • so blood glucose decreases causing glucagon secretion
  • glucagon causes glycogen to be converted to glucose
• state and explain why maintaining blood glucose levels is important

  cells need glucose for respiration

  to prevent diabetes

  to maintain homeostasis

  to ensure proper functioning of the nervous system
• explain the importance of repeating experiments in bio [4]

  • allows calculation of a mean result
  • reduced anomalies/ outliers
  • increases validity/ reliability of results
  • allows identification of anomalies
  • reduces impact of random errors
  • helps identify systematic errors
  • helps determine if results are reproducible
• what is speciation

  the formation of new species when two populations can no longer interbreed to produce fertile offspring
• explain the differences between neural and hormonal control mechanisms [3]

  • neural is faster
  • neural uses electrical impulses while hormonal uses chemicals in bloodstream
  • neural involves neurons while hormonal involves glands
  • neural has short lasting effects while hormonal has long lasting
• describe the impact of organic pollution on an aquatic ecosystem [3]

  • bacteria decay organic matter
  • bacteria respire aerobically
  • lowers oxygen conc in water
  • fish have less oxygen
  • reduced energy supply causes death of fish
  • can lead to eutrophication
• explain how global warming affects animals and their habitats [5]

  • rising temps causes habitat loss- eg. melting ice caps
  • changes in migrational patterns due to altered seasonal timings
  • risk of extinction for species unable to adapt quickly enough
  • changes in geographical distribution of species
  • reduced biodiversity in affected ecosystems
  • increased competition for remaining suitable habitats
• components of a single dna strand (diagram)

  rectangle- base

  circle- phosphate

  pentagon- sugar