Apparatus And Techniques

Question 1

What is a Colorimeter?

Answer 1

An instrument to quantitatively measure the intensity of color of a solution

Question 2

What is a cuvette?

Answer 2

A special rectangular test tube

Question 3

What is a calibration curve?

Answer 3

A method for determining the concentration of an unknown solution by comparing it to a range of know concentrations

Question 4

What is a potometer?

Answer 4

A device used to calculate the rate of transpiration

Question 5

What is a serial dilution?

Answer 5

A step wise dilution of a solution by a constant dilution factor

Question 6

What is a dilution series?

Answer 6

Progressive dilution of a solution by a variable dilution factor

Question 7

How would you use a light microscope?

Answer 7

1. Start with the lowest magnification objective lens
2. Put the slide onto the stage and hold it in place with the stage clips
3. Use the coarse focus to move the stage as close to the lens as possible without touching the slide
4. Look through the eyepiece and still using the coarse focus try to bring the picture as close to focus as you can
5. Use the fine focus to bring the picture into full clarity
6. Repeat with higher power lens if needed

Question 8

What is an eyepiece graticule?

Answer 8

See through ruler fitted inside the eyepiece
NOTE : An eyepiece graticule has no units which depend on the magnification

Question 9

What is a stage micrometer?

Answer 9

A slide with 1 Micrometer markings on it

Question 10

What is the test for reducing sugars?

Answer 10

1. Add Benedicts solution
2. Heat the sample
3. In the presence of a reducing sugar solution should turn Brick Red

Question 11

What is the test for a non-reducing sugar?

Answer 11

1. Boil sample in HCL
2. Add equal volume and concentration of NaOH to neutralise the acid
3. Add benedicts solution if there is a non-reducing sugar present the solution should turn orange / Brick red

Question 12

What is the test for starch?

Answer 12

1. Add Iodine solution
2. If starch is present solution will turn Blue/Black

Question 13

What is the test for lipids?

Answer 13

1. Add ethanol
2. Mix well
3. Add water
4. If a lipid is present a milky white emulsion should form

Question 14

What is the test for proteins?

Answer 14

1. Add biuret solution
2. In the presence of a protein the solution will turn purple

Question 15

What is electrophoresis?

Answer 15

Using electricity to separate DNA fragments by length

Question 16

How to carry out aseptic techique?

Answer 16

1. Disinfect working area
2. Flame the inoculating loop before and after transferring the microorganisms
3. Flame the mouth of the glass bottles to prevent any bacterial exchange in the air
4. Seal ASAP