6 Forensics Flashcards
What type of chemical reaction takes place in decomposition?
Hydrolysis
Why do we use multiple piles of leaves for an investigation?
To give a range for the independent variable.
Describe the role of bacteria from forests that leads to producing carbon dioxide.3
- decomposition of organic matter/ plant material
- bacteria produces hydrolytic enzymes
- respiration produces carbon dioxide
Suggest how carbon dioxide is returned to air from the oceans.1
Respiration/decomposition
State two features of these bodies that could account for variation in data.
- body size
- fat level
- position of the body
Explain why recording rectal temperature is more reliable than measuring skin temperature.2
- more core 37 degrees
- skin temp would be more variable
What factor might influence the rate of progress of rigid Morris in a muscle immediately after death?
Presence of drugs in the body
Explain why ambient temperature and the core temperature of the body are used to determine the Tod.3
- temperature of the body/core changes with time after death
- core temperature depends upon the ambient temperature
- idea that other post-death changes eg muscle contraction/insect life cycles and degree of decomposition depend on the ambient temperature of the body.
Describe the role of decomposers, such as microorganisms, in the carbon cycle.2
- decomposers break down organic material
- decomposer respire/ respiration takes place
- releasing CO2 into atmosphere
New data contributing to an understanding of the evolution of grey tree frogs has been investigated.
Suggest two ways in which the results of their investigations can be shared.2
- scientific/peer reviewed journals
- scientific lectures/ conferences
- media reports
In addition to body temperature, forensic scientists would look for other evidence of time of death.
Give two other pieces of evidence from a body that allow for an estimation of the time of death.2
- rigor mortis
- degree of decomposition
- forensic entomology
Suggest reasons for why
Species of plants cannot be identified from woody (xylem) material using PCR and DNA profiling.2
- xylem/wood is made of dead material it is not living
- No DNA or nucleic acid present
Suggest and explain what effect an increase in temperature has on the rate of decompostion on a pile of leaves.4
- increasing temp increases rate of D
- enzymes present so
- increased heat=increased collisions between enzymes and substarte
- increased rate at which bacteria grows due to favoured conditions
- at a certain temp rate slows/stops as too high enzymes will denature
Explain why there is a decrease in mass of leaves.4
- bacteria/ decomposers release enzymes for decompostion
- respiration of glucose and CO2 released
- formation of glucos and monomers that are soluble and will dissolve into ground or taken by othner organisms
- water loss from leaves (evaporation)
