Time of death and decompositionEdexcel A-Level Biology A: Mind map

Exam questions on Time of death and decomposition

1. A body is found in a room in a house at 10:00. The room temperature is 18 °C. The rectal temperature of the body is 31.0 °C. The pathologist records that rigor mortis is present in the muscles of the jaw, neck and arms but not yet in the legs. For this question, assume that the body temperature was 37.0 °C at death and that the body has cooled at a constant 1.5 °C per hour.
   Calculate the time that has passed between death and the discovery of the body. Show your working.2 marks
2. A body is found in woodland in June. Blowfly larvae are present and the largest are 14 mm long. No pupae are present. Laboratory data show that at 18 °C, the mean temperature recorded at the site, blowfly eggs laid on a body hatch after about 1 day and the larvae reach 14 mm in length 5 days after the eggs were laid.
   Estimate the minimum time since death and explain your answer.2 marks
3. At a forensic research facility, a team observes a human donor body left on the surface of woodland soil in summer. Decomposition passes through stages: fresh (0–3 days), bloat (4–7 days), active decay (8–15 days), advanced decay (16–30 days) and dry remains (over 30 days). Blowflies are the first insects to arrive, followed in turn by flesh flies, then carrion beetles during active decay, and finally hide beetles and mites on the dry remains.
   Explain how the stage of succession on a body found in similar woodland could be used to estimate the time of death.3 marks