General

Question 1

How do you produce a calibration curve?

Answer 1

1. Say the exact concentrations to use when creating solutions.
2. Measure and record absorbance value of each concentration using a colorimeter.
3. Plot a graph with concentration on the x-axis and absorbance value on the y-axis.
4. Draw a curve.
5. Read off the concentration from the graph.

Question 2

What to say when evaluating?

Answer 2

You could say: no statistical test to see if the difference is significant.

Question 3

How do you handle a scalpel safely?

Answer 3

1. Cut away from yourself and others.
2. Cut against a flat surface.

Question 4

What type of graph to plot when looking at the relationship between two independent variables?

Answer 4

It is a scatter graph.

Question 5

What to include when asked if the data in the table supports a conclusion?

Answer 5

You MUST include figures from the table.

Question 6

Why is a log scale used to record the number of cells?

Answer 6

1. Large range.

Question 7

Why use micrograms when measuring concentration of ammonia in soil?

Answer 7

1. Very little ammonia.

Question 8

Why use micrograms per gram?

Answer 8

1. Per gram so values can be easily comparable.

Question 9

A student used a dilution series to investigate the number of cells present in a liquid culture of bacteria. Describe how he made a 1 in 10 dilution and then used this to make a 1 in 1000 dilution of the original liquid culture of bacteria

Answer 9

1. Add 1 part culture to 9 parts liquid.
2. Mix
3. Repeat usign 9 parts fresh liquid and 1 part of 0.1 and 0.01 dilution to make 0.001 dilution