Drawing diagram:
-use HB pencil, no mechanical pencil
-clear unbroken lines
-more than 70% area covered
-draw same number of structures as shown
-keep same relative size
-dont use scale or compass
Labellling:
-use scale to make straight labelling lines
-label lines always horizontal, dont intersect
Measurement:
-always measure in mm
- when writing magnification, write X before it,
e.g X25, X30, X60, X100
-When asked to measure diameter, draw dotted line on diameter of structure, then measure in mm
-for measuring curved object, measure in multiple straight line segments
Comparison points of diagrams:
-Shape (circular, rectangular)
-Additional features
-Number of structures (No. of chloroplast or ribosomes etc)
-Size (bigger,smaller etc.)
Abbreviate as SANS
Line graph drawing:
-draw x and y axis line, label it ( on complete top of y axis, write y axis, on complete right of x axis,
write x axis)
-label axis with units (format is type of quantity/unit e.g Length/mm or Temp C
-to plot, first column of table is x axis(independent variable on x), second column on y axis(dependent
on y)
-cover more than 70% of graph using appropriate scale
-dont plot with X or just dot, instead plot with dot and circle the dot
-Incase of a graph that isn't linear, connect one point after another with scale, and dont make free
hand curve, only make curve if asked specifically by Q
-Dont add extra detail (if graph starts from 10 on x axis, then dont connect graph line with origin)
Bar Chart
-Width of bars consistent
-space between bars consistent
-Cover more than 70%
-axis rules same from line graph rules
Histogram
-width of bars consistent
-cover more than 70%
-same rules for axis as in line graph
Table drawing
-use pencil only
-use scale
-Same width of columns
-correct headings with units (same format of writing as was written in line graph eg Length/mm)
-dont write units with the data in table (unit only in heading)
-independent column first, then dependent
Plan an investigation:
Control
Observation & Organism
Record and Repeat
Measurements
Standardize and safety
Remember that a control is an investigation that is identical to the original but with the factor you are
investigating removed. This allows for comparison in order to determine that the factor that is being
investigated is the thing that is causing the results.
(b) (v) The student decided it would be better to calculate the rate of respiration per gram of animal so
that the values could be compared. Describe how the student could find out the rate of respiration per
gram of animal.
[2] Answer: ● Measure the mass of the animal; [1 mark] ● Divide the rate of respiration / movement of
bubble by the mass (in grams); [1 mark]
Plan and Investigation questions (Tips):
How independent variable is being handles
How dependent variable is measured
3 control variables
Control Experiment
Repeat experiment 2 or 3 times for reliability
Also include safety measure
I Don’t Care So Please Run Away (IDCSPRA)
IV- State the independent variable, describe how you change it
DV- State Dependent variable, State Units and state how will we measure it
CV- State 3 control variables and state how you are going to control them
Procedure- method to test the hypothesis
Safety- State a safety measure and how would you eliminate the risk
Repeat- State Repeat experiment 2 or 3 times
Average- State that you would calculate average (Numerical Data if given)
(iii) The students wanted to obtain a more accurate value for the temperature at which amylase works
best. Suggest further investigative work that the students should carry out. [2] Answer: ● Test at smaller
intervals of temperature; [1 mark] ● Select a narrower range of temperatures around 35 °C; [1 mark]
When writing a plan for an investigation you should always begin by considering the variable that will be
changed on purpose (the independent variable), the variable that will be measured (the dependent
variable) and any variables that you will need to keep constant. You can then gain additional marks for
describing extra details of the method. Don’t forget to consider general points that will be relevant to all
investigations, such as a suitable number of repeats and safety considerations.