DATA
X-axis
The variable the scientist deliberately changes.
Independent variable
A student writes the aim "To see what happens to plants." Whats missing
IV and DV
What is the difference between hazard and risk
Hazard is the item responsible for the risk
The organelle that contains most of a cell's DNA.
Nucleus
Units
A plant investigation changes the distance between a lamp and the plant. This distance is this variable.
Independent variable
Which one is a hypothesis? A: "To investigate the effect of salt on the boiling point of water." B: "If salt is added to water, then its boiling point will increase."
B
Name the three parts of a risk assessment
Hazard, Risk and Control/Safety Measure
The number of chromosomes in a human body cell.
46 (23 PAIRS)
The graph type for acid concentration (M) vs volume of gas (mL).
Line graph
A student changes both water temperature and stirring speed in the same trial. This is why the results cannot be trusted.
More than one variable was changed, so it is not a valid test
Hypothesis: "If acid concentration increases, then more gas is produced." Name the IV and DV, and write the matching aim.
IV = acid concentration (M), DV = volume of gas (mL), "To investigate the effect of acid concentration on the volume of gas produced"
Maryam plugs in the microscope. Name the risk and one control measure.
Electric shock; keep hands dry and check the cord for damage
Cell division that makes two identical cells for growth and repair.
Mitosis
The key rule behind the line of best fit
Approximately equal numbers of points above and below it to show the general trend
A setup with no fertiliser added, used to compare against the fertilised plants
Control experiment/group
Write a hypothesis, with a reason, for how temperature affects how fast glucose dissolves.
If temperature increases, then glucose dissolves faster, because particles have more kinetic energy and collide more often
Miss Salem adds iodine solution to the leaf on a tile. Name the risk and one control measure.
Staining or irritation of skin and eyes; wear gloves and safety glasses
One strand of DNA reads A-T-G-C-C-A. This is the complementary strand
T-A-C-G-G-T
When magnesium reacts with HCl, the volume of gas levels off over time. This word describes it.
Plateau
A stopwatch is always 1 second fast, but gives the same reading every trial. Are the results reliable, accurate, both or neither
Reliable but not accurate
A student's results do not support their hypothesis. This is what they should do.
State the hypothesis was not supported, without disregarding the data
Omair heats ethanol in a test tube in a hot water bath. Give the hazard, the risk and a control measure.
Ethanol is flammable; it could catch fire and cause burns; turn off the Bunsen before heating ethanol in the water bath
During the Industrial Revolution, dark peppered moths became more common than pale ones. Explain why.
Natural selection: dark moths were camouflaged on trees, so fewer were eaten, and they survived to pass on the dark allele