Paper 1&2 RPs Flashcards
When an object is placed into a displacement can water pours out. What is the volume of water equal to?
The volume of the object
Why should an object be fully submerged before you measure the water displaced?
So that the measurement is accurate
What equation links density, mass and volume?
Density = mass / volume
A block of clay has a volume of 50cm3 and a mass of 65g. Calculate the density in kg/m3.
Density = 0.065 / 0.00005 = 1300 kg/m3
Calculate the volume of a 0.5m3 cube in cm3.
500 000 cm3
A block has a density of 4.2g/cm3. The volume is 500000cm3, what is the mass of the block in kg?
Mass = 4.2 x 500 000 = 2 100 000 g = 2100 kg
Define specific heat capacity.
The amount of energy it takes to increase 1kg by 1°C
What are the units for specific heat capacity?
J/kg °C
State the equation that links current, potential difference and power.
P= I x V
How do you calculate the gradient of a line?
Change in y / change in x
Rearrange to make mass the subject:
m = ΔE / c x Δθ
What is the following circuit symbol?
Voltmeter
What piece of equipment is used to measure temperature?
Thermometer
Why is the metal block wrapped in insulation?
To prevent thermal energy dissipating to the surroundings
Name a substance that can be used to stain cells before viewing with a microscope?
Iodine or methylene blue
How do we find the overall magnification of a microscope?
Eyepiece x Objective lens
What does a plant vacuole contain?
Cell sap
How have electron microscopes improved our understanding of sub-cellular structures?
Allowed us to see smaller objects, e.g. ribosomes
Give a similarity between a bacterial cell and a plant cell.
Cell wall, cytoplasm, cell membrane, ribosomes
Give a difference between a bacterial cell and a plant cell.
Chloroplast, nucleus, vacuole, mitochondria
How much space should a scientific drawing take up?
At least half the space
True or false? Scientific drawings should be coloured or shaded.
False
Define osmosis.
The diffusion of water from a dilute solution to a concentrated solution across a partially permeable membrane
What part of a cell is involved in osmosis?
Membrane
What does hypotonic mean?
Solution with a low solute concentration
What does isotonic mean?
Solution with the same solute concentration
What is an independent variable?
Variable that is changed in an experiment
What is a control variable?
Variable that is kept the same
What is a dependent variable?
Variable that is measured and recorded
What is a ripple tank?
A piece of equipment used to observe water waves
What piece of apparatus can be used with a ripple tank to make it easier to make measurements?
Strobe light (freezes the waves, making them easier to count)
How is wave speed calculated?
Frequency x Wavelength
What is a longitudinal wave?
A wave with oscillations parallel to the direction of energy transfer
What is defined as ‘the highest point on a wave’?
Crest
State the speed of UV light through a vacuum.
3 x 10^8 m/s or 300,000,000 m/s
What do waves transfer?
Energy
What are the SI units for wavelength?
Metres, m
Name 2 pieces of apparatus used to detect the amount of infrared radiation given out by different surfaces.
Glass thermometer, infrared thermometer
Why are IR thermometers better than glass thermometers?
They are not affected by the surface temperature
What happens to frequency of the EM spectrum, from radio waves to gamma rays?
Increases
What is the trough of a wave?
The lowest point
If a twig is dropped into a calm body of water why doesn’t it move?
Waves transfer energy, not matter
True or false – all bodies absorb and emit infrared radiation.
True
What is the relationship between object temperature and how much IR it emits?
Higher temperature = more IR
What is the wavelength of a 20Hz wave travelling at 4 m/s?
0.2 m
What enzyme is responsible for breaking down carbohydrates?
Amylase
What enzyme is responsible for breaking down proteins?
Protease
What enzyme is responsible for breaking down lipids?
Lipase
What does starch break down into?
Glucose
What do lipids break down into?
Fatty acids and glycerol
What do proteins break down into?
Amino acids
Which 2 reagents can be used to test for lipids?
Ethanol, Sudan III
Which food test is semi-quantitative and why?
Benedict’s – the end colour depends on the sugar concentration
State two factors which affect reaction times.
Caffeine, distractions, age, alcohol, tiredness
Apart from the ruler drop test, how else can reaction times be tested?
Using a computer programme which tests reaction time
Describe one control variable for the ruler drop test.
Dominant or non-dominant hand, hours of sleep, number of caffeinated drinks, etc
Which type of neurone carries impulses through the CNS?
Relay
Define effector.
Muscle or gland which produces the response
Give an example of an effector.
Any muscle or gland
Define stimulus.
Change in environment
Give an example of a stimulus for the skin.
Heat, e.g. candle, touch, e.g. feather
What is a mixture?
More than one substance mixed, but not chemically joined
What does pure mean?
A single element or compound
Give another method that can be used to determine the purity of a substance.
By finding its melting or boiling point
How do impurities affect the boiling point of a substance?
Increase it
Which parts of the electromagnetic spectrum are absorbed by the chlorophyll molecule?
Blue and red visible light
What is the calculation for Rf value?
Distance moved by solute / Distance moved by solvent
In chromatography the stationary phase is ____________.
Solid
In chromatography the mobile phase is ___________.
Solid, Liquid, Gas
Name 2 ways of measuring the oxygen given off by a plant during photosynthesis.
Counting bubbles, collecting in upturned measuring cylinder
Describe the relationship between distance and number of bubbles given off during photosynthesis.
As distance increases, fewer bubbles of oxygen are produced
What do we call factors that reduce that rate of photosynthesis?
Limiting factor
Apart from light intensity name 2 factors that affect the rate of photosynthesis.
Carbon dioxide concentration, temperature
What reactant for photosynthesis enters the plant through the roots?
Water
Through which process does the substance you named in Q5 enter the roots?
Osmosis
True or false? Rf values are always greater than one.
False – always less than 1
Why can the substances in a mixture be separated?
They are not chemically joined
Name a gas that causes acid rain.
Nitrous oxides, sulphur dioxide
Name a greenhouse gas.
Carbon dioxide, methane, water vapour
Suggest two factors that caused carbon dioxide levels to decrease in the Earth’s early atmosphere.
Evolution of green plants (and therefore photosynthesis), dissolved in water, locked up in sediments and rocks
Which stage is used to destroy microbes when treating water?
Sterilisation
Briefly describe how potable water is made from seawater.
Water is heated until it boils. The salt remains in the liquid, and the steam is pure water. The steam is cooled and condensed to make potable water./Reverse osmosis
Explain the role of anaerobic bacteria in the treatment of sewage.
Sewage sludge is digested anaerobically by specific bacteria
Which two planets currently have an atmosphere similar to the early atmosphere of the Earth?
Venus and Mars
Name 3 different stores of carbon in the carbon cycle.
Fossil fuels, rocks, compounds in plants and animals
What is a transect?
A transect is a line across a habitat or part of a habitat
What is a quadrat?
A square frame with a known area that can be used to sample a habitat
What does population mean?
The number of individuals of a species in an area
What is defined as ‘the area where an organism lives’?
Habitat
Give an advantage of estimating population size instead of measuring true population size.
Impossible to count all of the organisms in a population
Why will light intensity affect the distribution of plants?
Light is required for photosynthesis so higher light intensity would lead to a higher plant population
What is the difference between abundance and distribution?
Abundance is how many; distribution is where they are found
