exam questions

• state 2 conditions which allow a body to be preserved(2)

  • lack of oxygen- microorganisms cannot respire aerobically
  • low temps- enzymes below optimum temp so activity is low
• outline stages of rigor mortis which take place after death(4)

  • lack of o2 means muscles respire anaerobically
  • lactic acid is produced=muscles acidic/low PH
  • low PH denaturres ATPase enzyme
  • no ATP produced so myosin head stays attached to actin filament
  • mucles remain contracted/stiff
• explain how studying insect succession can establish TOD(3)

  • record which insects present on body
  • take into account which stages of lifecycle they are at
  • establish TOD
• decribe changes that occur in body the first week after death(3)

  • body temp falls
  • rigor mortis occurs
  • break down of cells or tissues by enzymes
  • bloating/accumulation of gas following break down
• describe the role of decomposers in the carbon cycle(2)

  • decomposers break down organic material
  • decomposers respire releasing C02 into atmosphere
• explain affect of temperature on rate of decomposition

  • increased temp with increase rate of decomposition
  • increased temp increases enzyme activity
  • increased temp increases growth rate of bacteria/fungi/decomposers
  • OR could denature enzymes, slowing rate of decomposition