GCSE Biology

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  1. what is the relationship between the size of mammals and their surface area : volume ratio
    • the larger their size
    • the smaller he surface area : volume ratio
  2. seal x is a mammal that lives in the very cold seas of the arctic . It grows to a length of 2.5m and 400kg explain two ways in which seal x is adapated to surviving in vert cold conditions
    seal x below
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    • it has a small surface area to volume ratio to reduce heat loss
    • it has layers of fat to insulate it
  3. avoiding excess water loss os one of the major problems facing plants and small rodents living in a desert
    describe and explain two structual adaptations of deser plants which limit water loss
    • plants in dry areas much reduce water loss through stomata , so they may have no leaves at all
    • a few stomata in the stem surface are protected by hairs or placed deep in ridges . This reduces the speed of air moving across the stomata and so reduces the rate of evapouration
  4. hormones are involved in the development of follicies describe how
    • FSH released by pituitary gland
    • hormone travels in blood
    • FSH stimulates the growth of follicles
    • follicile produces oestrogen
    • oestrogen inhibits FSH production
    • LH brings about ovulation
  5. an FSH injection might cause ovulation in a woman who was infertile . Explain how
    because FSH stimulates development of follicles
  6. Clomiphene blocks the action of oestrogen . Suggest how treatment with clomiphine might cause ovulation
    oestrogen inhibits FSH production
  7. what is an ecosystem
    a habitat + community which are influenced by biotic and abiotic factors in the environment
  8. the % of light energy trapped by the producers is very low . Give two reasons why
    • light may be reflected or absorbed by water
    • light could be reflected from producers
    • light could be lost in photosynthesis
  9. the biomass of primary consumers is less than the biomass of producers explain why
    because energy is lost from the primary consumer through respiration , faeces , movement and temperature regulation . Also the plant uses energy through respiration so less energy is passed onto tne primary consumer
  10. decsribe the process of IVF
    • FSH matures egg and LH releases egg
    • eggs collected from ovary
    • fertilisation occurs
    • fertilised egg divides
    • embryo formed
    • inserted into womb
  11. explain how the MRSA strains of bacteria became difficult to treat
    • mutation
    • causes resistance
    • to antibiotic
  12. exercise helps a person to loose weight explain why
    • increases metabolic rate
    • fat stores broken down
  13. what happens to peoples bodies when they become dependant on a drug
    • drug alters chemical processes in the body
    • person suffers withdrawal symptoms
  14. the overall effect of alochol on the health of the UK population is much more than that of heroin . Suggest why
    many more people use alcohol so the effect is multiplied
  15. what does the theory of evolution state
    present day organism have evolved from simpler organisms over millions of years
  16. what is meant by natural selection
    best adapted organism survives and go on to breed and genes past onto next generation
  17. why did people disgree with Darwin's theory in the past
    • religious objections
    • insufficient evidence
  18. give one way in which Darwins theory differs from Lamracks
    Darwins theory depends on differences in genes at birth
  19. describe the stages of adult cell cloning
    • nucleaus removed
    • from unfertilised egg
    • nucleus from body cell of desired animal wanted to produce a clone of
    • inserted into egg
    • electric shock
    • to make cell divide
    • embryo inserted into host mother
  20. explain what is meant by a clone
    genetically identical
  21. most people would be opposed to cloning a human from a deep-frozen , long-dead relative suggest why
    ethical reasons
  22. which organ in the body produces cholestrol
  23. which organ may be dmaged by high levels of cholestrol in the blood
  24. other than increasing fitness , give two reasons why regular exercise is important in diet
    • decreases blood pressure
    • increases metabolic rate
  25. name one factor , other than diet , which affects the level of cholestrol in the blood
  26. describe the relationshio between the types of lipoprotein in the blood and and heart disease
    • balance between two important for good heart health
    • high LDL causes heart disease
    • high HDL reduces heart disease
  27. what is meant by metabolic rate
    rate of chemical reaction in cells
  28. other than heart disease name two conditions that are linked to obesity
    • diabetes
    • arthritis
  29. what is meant by pandemic
    disease prevalent over the world.
  30. explain why a mutation of the influenza vaccine may cause another influenza pandemic
    • any three from
    • strain of flu
    • vaccination not effective
    • antiviral drugs not effective
    • people not immune to it
    • virus not recognised by white blood cells
    • people travel abroad spreading infection
  31. explain how the MMR vaccine protects children from mumps , measles and rubella
    • vaccine contains a dead form of pathogen
    • stimulates antibody production
    • by WBC
    • antibodies kill pathogen
    • antibodies quickly produced on reinfection
  32. explain why it is difficult to treat disease caused by viruses
    • live inside body cells
    • drug would kill our body cell
    • or
    • antibiotics ineffective against viruses
    • viruses mutate frequently
  33. explain how the MRSA becaterium has developed resistance to antibiotics
    • mutation
    • natural selection
  34. explain why the MRSA is causing problems in hospitals
    • resistant to most antibiotics
    • contagious
    • patients ill therefor less able to combat disease
  35. how do bacteria and viruses make us feel ill
    • bacteria produce toxins
    • viruses cause toxins to be released from cell or damage cells
  36. explain why , there has been a large increase in the number of antibiotic resistant strains of bacteria
    • overuse of antibiotics
    • bacteria mutate
    • antibiotics kill non resistant strains
    • reduced competition
    • resistant bacteria reproduce
  37. what is the main purpose of pre clinical testing
    testing for toxicity
  38. what is the purpose of phase 1 testing
    testing for side effects
  39. in phase 1 testing , healthy volunteers are used rather than patients suggest why
    • higher risk for patient
    • or might conflict with patients treatment
  40. what is the main purpose of phase 2 and phase 3 testing
    to find optimum dose
  41. what is meany by a placebo
    tablet/drug/injection that does not contain drug
  42. explain how the action of a drug makes a person become addicted to it
    alters body chemistry
Card Set:
GCSE Biology
2012-06-11 20:21:46
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