A3 First

People who work in environmental protection Ecologists Energy managers Environmental managers Environmental consultants Recycling officers Conservation officers

Environmental protection officers Monitor industrial sites Check for water pollution Check flood risks Monitor air quality Protect wildlife

Public laboratories are accredited to check the accuracy and precision of the laboratories results. They must: Adhere to H&S regulations Train their staff Maintain and check their equipment and instruments

To check a lab is producing accurate evidence, proficiency tests are carried out. Identical samples sent to laboratories Samples are analysed Results are compiled Report is sent back to laboratory highlighting if the results differed from other results

Samples taken are stored Sterile container to prevent contamination Suitable temperature to avoid deterioration Sealed to prevent contamination or tampering

Monitoring the effects of climate change In the oceans: As the oceans warm up Species that live in cold water move northwards towards colder water Species that live in northerly regions become extinct North

Monitoring pollution in freshwater Scientists look at indicator organisms Certain fresh-water invertebrates only live in very clean water Some species can live in polluted water What is there shows the level of pollution This is called a biotic index

Recording visual examination results Written descriptions (give detail) Sketches or drawings (when accuracy not important) Photographs (accurate details) Video (shows movement)

Features of an image Sharpness Is image sharp or blurred?

Features of an image Contrast Extent to which parts of the image stand out from other objects and the background

Features of an image Depth of field Extent to which an object or objects at different distances from camera are in focus. Narrow depth of field

Features of an image Magnification Size of image in relation to size of object

Error in measurements Difference between measured value and true value.

Types of error Random Values vary unpredictably Equipment not sensitive or measurements difficult to make Systematic Values vary from true value but in a consistent way Instrument incorrectly calibrated Operator consistently making same errors

Data collection If everyone uses the same methods to collect data then repeatability and reproducibility are increased.

Qualitative tests Identification tests Detect presence of substances E.g. Litmus paper or a pregnancy test

Quantitative tests Tells you how much of a substance is present E.g. Indicator solution for pH or a pregnancy test which tells you how many days pregnant you are.

Assessing water quality Water can be: Pure Containing dissolved solids Containing suspended solids

Turbidity Measure of the cloudiness of the water.

Turbidity is measured with: Turbidity tube Turbidity meter Secchi disk

A3 Second

Environmental protection workers Ecologists Energy managers Environmental managers Environmental consultants Recycling officers Conservation officers

Environmental protection officers Monitor industrial sites Check for pollution – air and water Check flood risks Protect wildlife

Public laboratories are accredited for accuracy and precision of results. They Follow H&S Train staff Maintain & check equipment

To check a labs produce accurate evidence, they do proficiency tests Identical samples sent to lab Samples analysed Results compiled Report is sent to lab to show if results accurate

Sample storage Sterile container - prevents contamination Suitable temp - avoids deterioration Sealed - prevents contamination / tampering

Monitoring climate change As the oceans warm up Species move north to colder water Species living in north become extinct North

Monitoring freshwater pollution Indicator organisms Some fresh-water invertebrates only live in clean water Some only live in polluted water Used to measure level of pollution - biotic index

Recording visual results Written - detail Sketches / drawings – accuracy unimportant Photographs – accuracy important Video – captures movement

Features of an image

Sharpness Is image sharp or blurred?

Contrast Do parts of image stand out from others?

Depth of field How far away from camera are objects in focus? Narrow depth of field

Magnification Size of image in relation to real object

Error Difference between measurement and true value.

Types of error Random Values vary unpredictably Equipment unsensitive / measurements difficult Systematic Values vary but consistently Instrument incorrectly calibrated / operator making same errors

All use same methods to collect data Data collection All use same methods to collect data Repeatability & reproducibility increased.

Qualitative tests Identification tests to detect presence E.g. Litmus paper (pH) / pregnancy test

Quantitative tests How much of a substance is present? E.g. Indicator solution (pH) / pregnancy test which tells you no. of days preg.

Water quality Pure Contains dissolved or suspended solids

Turbidity Cloudiness of water

Turbidity measurement Turbidity tube Turbidity meter Secchi disk

A3 Third

Environmental protection workers Ecologists Energy and environmental managers Environmental consultants Recycling and conservation officers

Environmental protection officers Industrial sites Pollution – air and water Flood risks Wildlife

Public laboratories accreditation for accuracy and precision H&S Train staff Maintain & check equipment

Proficiency tests to check lab accuracy Identical samples sent Samples analysed Results compiled Report sent

Sample storage Sterile & sealed container - contamination Suitable temp - avoids deterioration

Monitoring climate change Oceans warm up Species move north – colder Northern species become extinct North

Freshwater pollution Indicator organisms Some like clean water, some like polluted. Measurement of pollution level - biotic index

Recording results Written - detail Sketches / drawings – accuracy unimportant Photographs – accurate Video –movement

Features of an image Sharpness – sharp / blurred Contrast – can you see certain parts? Depth of field – how far from camera in focus? Magnification – how much bigger than reality?

Sharpness Sharp or blurred?

Contrast Parts of image stand out?

Depth of field How far away from camera in focus? Narrow depth of field

Magnification Size in relation to reality

Diff between measurement & reality Error Diff between measurement & reality

Types of error Random Vary unpredictably Equipment unsensitive Systematic Vary predictably Instrument uncalibrated / operator errors

Repeatability & reproducibility Data collection All use same methods Repeatability & reproducibility UP

Qualitative tests Identification tests to detect presence E.g. Litmus paper (pH) / pregnancy test

Quantitative tests How much of a substance is present? E.g. Indicator solution (pH) / pregnancy test which tells you no. of days preg.

Water quality Pure Dissolved or suspended solids

Turbidity Cloudiness

Turbidity measurement T. tube T. meter Secchi disk

A3 Fourth and final!!!!

Environmental protection workers Ecologists Energy and environmental managers Environmental consultants Recycling and conservation officers

Environmental protection officers Industrial sites Pollution – air and water Flood risks Wildlife

Public laboratories accreditation for accuracy and precision H&S Train staff Maintain & check equipment

Proficiency tests to check lab accuracy Identical samples sent Samples analysed Results compiled Report sent

Sample storage Sterile & sealed container - contamination Suitable temp - avoids deterioration

Monitoring climate change Oceans warm up Species move north – colder Northern species become extinct North

Freshwater pollution Indicator organisms Some like clean water, some like polluted. Measurement of pollution level - biotic index

Recording results Written - detail Sketches / drawings – accuracy unimportant Photographs – accurate Video –movement

Features of an image Sharpness – sharp / blurred Contrast – can you see certain parts? Depth of field – how far from camera in focus? Magnification – how much bigger than reality?

Sharpness Sharp or blurred?

Contrast Parts of image stand out?

Depth of field How far away from camera in focus? Narrow depth of field

Magnification Size in relation to reality

Diff between measurement & reality Error Diff between measurement & reality

Types of error Random Vary unpredictably Equipment unsensitive Systematic Vary predictably Instrument uncalibrated / operator errors

Repeatability & reproducibility Data collection All use same methods Repeatability & reproducibility UP

Qualitative tests Identification tests to detect presence E.g. Litmus paper (pH) / pregnancy test

Quantitative tests How much of a substance is present? E.g. Indicator solution (pH) / pregnancy test which tells you no. of days preg.

Water quality Pure Dissolved or suspended solids

Turbidity Cloudiness

Turbidity measurement T. tube T. meter Secchi disk

A4 Round 1

Scientific experts need good Scientific knowledge and understanding Observational Measurement skills Analytical }

Public analysts need good understanding of Chemical analysis Law Latest food technology

Public analysts Check to see if H&S standards are being met Monitor food safety Check labelling Monitor compliance with legislation Provide research and advice on diseases caused by food

} Law Enforcement Crime scene investigators (CSIs) Scenes of crime officers (SOCOs) Record Collect Evidence from crime scenes Package }

} CSIs and SOCOs Collect fingerprints Examine: victims suspects for forensic evidence locations }

Forensic Evidence Hairs Fibres DNA

Forensic Scientists Analyse information from crime scenes collected by CSIs and SOCOs Do other things such as paternity testing Use electrophoresis

Colorimetry If a coloured chemical is dissolved in a liquid the intensity of colour of the solution increases as more of the chemical is added.

Colorimeter Used to measure intensity of colour Provides quantitative information Allows measurement of concentration of coloured chemical in a solution

Magnification = eyepiece lens x objective lens Light microscopes Magnification = eyepiece lens x objective lens Resolution – min. distance required between to points so they can be seen as separate Depth of field – range of distances within which specimen is in focus. Light microscopes have a narrow depth of field so must be focused exactly on object being examined

Use beam of electrons, not light Electron microscopes Use beam of electrons, not light Allow much greater: magnification resolution depth of field

Microscopes Electron vs. light Expensive Cheap Static Portable Slow Quick Sample must be dead Sample can be living

Chromatography Technique used to find out what unknown substances are made up of. Thin layer chromatography uses a TLC plate instead of paper. Made of silica gel on glass.

Chromatography phases Mobile – solvent used to move substance Stationary – medium substance moves through e.g. Paper Solvent Water if substance dissolves in aqueous solution Alcohol if substance does not dissolve in aqueous solution

Paper chromatography method If substance is solid, dissolve in liquid Draw pencil line on chromatography paper Place spot of liquid on paper. Allow to dry Place bottom of paper into solvent Solvent rises up through paper and carries spot with it Chemical in spot separate leaving marks on paper Small molecules travel furthest

Rf value is how much substance moves in comparison to solvent. Rf value = Distance travelled by substance Distance travelled by solvent Rf value = small number big number

Electrophoresis Separates different biological molecules e.g. proteins Used on small biological samples Helps produce DNA profiles

Electrophoresis method Sample placed on absorbent material e.g. gel Charge passed across material Opposites attract -- particles  + electrode + particles  -- electrode Distance travelled depends on size of molecule and charge. Small molecules with large charge travel furthest.

Developments in DNA Polymerase chain reaction (PCR) DNA databases Produces lots of copies of DNA so tiny amounts can be analysed DNA databases Contain profiles of people connected with crimes Stored on national DNA database Allow quick, accurate and reliable comparisons of DNA samples

A4 Second run through!

} Scientific experts Scientific knowledge and understanding Observational Measurement skills Analytical }

Public analysts Chemical analysis Law Latest food technology

Public analysts Check to see if H&S standards are being met Monitor food safety Check labelling Monitor compliance with legislation Provide research and advice on diseases caused by food

Record, collect and package evidence from crime scenes Crime scene investigators (CSIs) Scenes of crime officers (SOCOs) Record, collect and package evidence from crime scenes

CSIs and SOCOs Collect fingerprints and examine victims, suspects& locations for forensic evidence

Forensic Evidence Hairs Fibres DNA

Forensic Scientists Analyse crime scene info Carry out paternity testing Use electrophoresis

Colorimetry If a coloured chemical is dissolved in a liquid the intensity of colour of the solution increases as more of the chemical is added.

Colorimeter Measures intensity of colour Provides quantitative info Determines concentration of coloured chemical in a solution

Magnification = eyepiece lens x objective lens Light microscopes Magnification = eyepiece lens x objective lens Resolution – min. distance between points that can be seen as separate Depth of field – range of distances within which specimen is in focus. Light microscopes = narrow depth of field

Use electrons, not light Electron microscopes Use electrons, not light Greater: magnification resolution depth of field

Electron Light Expensive Cheap Static Portable Slow Quick Sample dead Sample living

Used to determine what unknown substances are Chromatography Used to determine what unknown substances are

Phases Mobile – solvent used to move substance Stationary – medium substance moves through e.g. Paper Solvent Water Alcohol

Paper chromatography method If substance is solid, dissolve in liquid Draw pencil line on chromatography paper Place spot of liquid on paper. Allow to dry Place bottom of paper into solvent Solvent rises up through paper and carries spot with it Chemical in spot separate leaving marks on paper Small molecules travel furthest

Rf value - how much substance moves in comparison to solvent. Rf value = Distance travelled by substance Distance travelled by solvent Rf value = small number big number

Electrophoresis Separates biological molecules e.g. proteins Used on small biological samples Helps produce DNA profiles

Electrophoresis method Sample placed on absorbent material (gel) Charge passed Opposites attract -- particles  + electrode Distance travelled depends on charge & size of molecule Small molecules with large charge travel furthest.

Developments in DNA Polymerase chain reaction (PCR) DNA databases Produces copy DNA so tiny amount can be analysed DNA databases Profiles of people connected with crimes Stored on national DNA database Quick, accurate and reliable comparisons of DNA samples

A4 Third run through!

Scientific experts Scientific K&U Skills in: Observation Measurement Analysis

Public analysts Chemical analysis Law Latest food technology

Public analysts Check H&S standards Monitor food safety Check labelling Monitor compliance with law Give advice on diseases caused by food

Crime scene investigators (CSIs) Scenes of crime officers (SOCOs) Record, collect & package evidence

Which Forensic Scientists examine CSIs and SOCOs Check victims, suspects & crime scene for forensic evidence Hairs Fibres DNA Which Forensic Scientists examine

Colorimetry If coloured chemical is dissolved in liquid intensity of colour of the solution increases as more chemical is added.

Colorimeter Measures intensity of colour Provides quantitative info Determines concentration of coloured chemical

Magnification = eyepiece lens x objective lens Light microscopes Magnification = eyepiece lens x objective lens Resolution – min. distance between points seen as separate Depth of field – range of distances with specimen is in focus. Light microscopes = narrow depth of field

Electron microscopes Greater: magnification resolution depth of field

Electron Light Expensive Cheap Static Portable Slow Quick Sample dead Sample living

Used to determine what unknown substances are Chromatography Used to determine what unknown substances are

Phases Mobile – solvent (water or alcohol) Stationary – paper

Paper chromatography method If substance is solid, dissolve in liquid Draw pencil line on chromatography paper Place spot of liquid on paper. Allow to dry Place bottom of paper into solvent Solvent rises up through paper and carries spot with it Chemical in spot separate leaving marks on paper Small molecules travel furthest

Rf value How much substance moves compared to solvent Rf value = small number big number

Electrophoresis Separates biological molecules e.g. proteins Helps produce DNA profiles

Electrophoresis method Sample placed gel Charge Opposites attract Small molecules with large charge travel furthest

Developments in DNA Polymerase chain reaction (PCR) DNA databases

A4 Last run through!

Scientific experts Skills in: Observation Measurement Analysis

Public analysts skills Chemical analysis Law Latest food technology

Public analysts do what? Check H&S standards Monitor food safety Check labelling Monitor compliance with law Give advice on diseases caused by food

Crime scene investigators (CSIs) Scenes of crime officers (SOCOs) Record, collect & package evidence

Which Forensic Scientists examine CSIs and SOCOs Check victims, suspects & crime scene for forensic evidence Hairs Fibres DNA Which Forensic Scientists examine e.g.

Colorimetry If coloured chemical is dissolved in liquid intensity of colour of the solution increases as more chemical is added.

Colorimeter Measures intensity of colour Provides quantitative info Determines concentration of coloured chemical

Magnification = eyepiece lens x objective lens Light microscopes Magnification = eyepiece lens x objective lens Resolution – min. distance between points seen as separate Depth of field – range of distances with specimen is in focus. Light microscopes = narrow depth of field

Electron microscopes Greater: magnification resolution depth of field

Electron Light Expensive Cheap Static Portable Slow Quick Sample dead Sample living

Used to determine what unknown substances are Chromatography Used to determine what unknown substances are

Phases Mobile – solvent (water or alcohol) Stationary – paper

Paper chromatography method If substance is solid, dissolve Draw pencil line paper Spot of liquid. Allow to dry Place paper into solvent Solvent rises and carries spot with it Chemicals separate leaving marks on paper Small molecules travel furthest

Rf value How much substance moves compared to solvent Rf value = small number big number

Electrophoresis Separates biological molecules e.g. proteins Helps produce DNA profiles

Electrophoresis method Sample placed on gel Charge Opposites attract Small molecules with large charge travel furthest

Developments in DNA Polymerase chain reaction (PCR) DNA databases

Good luck!!!! Remember: There are no marks for an empty box. If you have time, write something! It is easiest to get the first few marks on a question. Don’t spend ages on one question until you have finished the paper.