Applied Science Unit 2
Suggest why laboratory technicians must complete health and safety training before they
are allowed to work in the laboratory - ANS to ensure that they are aware of the risk and
hazards in laboratories and how to deal with them.
Information that must be recorded for samples taken - ANS date
name of person handling samples
location (where sample is from and where it is transported to)
Flame test colours - ANS Barium (Ba2+)= Pale Green
Copper= Green Blue
Lithium= Crimson Red
Sodium (Na+)= Yellow
Potassium (K+)= Lilac
Calcium (Ca2+)= Orange-red
Properties of a suitable internal standard - ANS Internal standard is chemically related to
the compounds that are being analysed but it should not be naturally present in the sample.
Compounds which have the same functional groups.
Why are tubes containing blood samples enclosed in plastic watertight containers - ANS
Prevents degradation by water.
Two containers limits possibility of loss sample if one container is broken.
2 ways of reducing risks associated with hazards in labs - ANS Carry out risk assessment
, Use PPE for protection
Train staff in necessary procedures
Comparing light and electron microscopes - ANS Light Microscope
•Rely on light rays
•Typically magnify objects by 1000 to 2000 X
•Images seen in 2D
•Live specimen can be seen
Electron Microscope
•Electrons bombarded using high levels of energy
•Specimen is killed
•Colours cannot be detected
•Magnification roughly 2,000,000 X
How can the width of human hair be calculated using a graticule and a Light Microscope -
ANS •Mount hair on Microscope slide,use sellotape to hold the hair down.
•Measure number of divisions corresponding to width of hair on graticule.
•Look through graticule at a calibration slide to find number of divisions on calibration slide
corresponding to divisions on graticule.
•Calculate the true distance corresponding to divisions.
•Calculate width of hair.
Explain how Gel Electrophoresis can be carried out in a school or college laboratory - ANS
•Prepare the agarose gel tray, place this tray into Electrophoresis chamber.
•Submerge gel using diluted electrophoresis buffer.
•Load wells with dye samples and place safety cover.
•Connect wires to the power source and begin electrophoresis by loading current through
the gel.
•Use a timer to observe time taken for dyes to travel.
•Once completed remove gel and casting tray from chamber.
Suggest why laboratory technicians must complete health and safety training before they
are allowed to work in the laboratory - ANS to ensure that they are aware of the risk and
hazards in laboratories and how to deal with them.
Information that must be recorded for samples taken - ANS date
name of person handling samples
location (where sample is from and where it is transported to)
Flame test colours - ANS Barium (Ba2+)= Pale Green
Copper= Green Blue
Lithium= Crimson Red
Sodium (Na+)= Yellow
Potassium (K+)= Lilac
Calcium (Ca2+)= Orange-red
Properties of a suitable internal standard - ANS Internal standard is chemically related to
the compounds that are being analysed but it should not be naturally present in the sample.
Compounds which have the same functional groups.
Why are tubes containing blood samples enclosed in plastic watertight containers - ANS
Prevents degradation by water.
Two containers limits possibility of loss sample if one container is broken.
2 ways of reducing risks associated with hazards in labs - ANS Carry out risk assessment
, Use PPE for protection
Train staff in necessary procedures
Comparing light and electron microscopes - ANS Light Microscope
•Rely on light rays
•Typically magnify objects by 1000 to 2000 X
•Images seen in 2D
•Live specimen can be seen
Electron Microscope
•Electrons bombarded using high levels of energy
•Specimen is killed
•Colours cannot be detected
•Magnification roughly 2,000,000 X
How can the width of human hair be calculated using a graticule and a Light Microscope -
ANS •Mount hair on Microscope slide,use sellotape to hold the hair down.
•Measure number of divisions corresponding to width of hair on graticule.
•Look through graticule at a calibration slide to find number of divisions on calibration slide
corresponding to divisions on graticule.
•Calculate the true distance corresponding to divisions.
•Calculate width of hair.
Explain how Gel Electrophoresis can be carried out in a school or college laboratory - ANS
•Prepare the agarose gel tray, place this tray into Electrophoresis chamber.
•Submerge gel using diluted electrophoresis buffer.
•Load wells with dye samples and place safety cover.
•Connect wires to the power source and begin electrophoresis by loading current through
the gel.
•Use a timer to observe time taken for dyes to travel.
•Once completed remove gel and casting tray from chamber.
