BTEC Applied Science Unit 3 Exam 143 Questions with Answers
What is a hypothesis? -CORRECT ANSWER An Idea that you can test using practical
... [Show More] experiments
What are the Key features of a good hypothesis? - CORRECT ANSWER A good Hypothesis must:
Be able to be tested scientifically
Relate one dependent variable to on independent variable
What is a Null Hypothesis? - CORRECT ANSWER States that there is no relationship or causality, for example, no relation between the temperature and the rate of reaction.
What does qualitative data refer to? - CORRECT ANSWER It refers to the appearance or value of something, such as the colour observed or whether the bubbles are produced.
What does Quantitative data refer to? - CORRECT ANSWER It refers to numerical measurements made, such as the volumes and times measured.
What is SOP? - CORRECT ANSWER The Standard Operating Procedure. This is an established procedure or method used to carry out a routine activity. It ensures consistent results every time.
What are some examples of SOPs? - CORRECT ANSWER Titration, Handling of chemicals, disposal of waste, qualitative analytical tests, preparing solutions
What are risk assessments? - CORRECT ANSWER It identifies hazards, evaluates the risks associated with those hazards and it determines ways to eliminate or control those risks.
What is a Hazard? - CORRECT ANSWER When the equipment or substance can cause harm, for example a hot plate or hydrochloric acid
What is a risk? - CORRECT ANSWER The harm that the hazard could cause and the chances of it happening, for example the risk of using a hot plate is getting burnt.
What is the independent variable? - CORRECT ANSWER The variables you change during an investigation.
What is the Dependent variable? - CORRECT ANSWER The variables you are investigating and measure during an investigation.
What is the control variable? - CORRECT ANSWER The variables you keep constant during an investigation.
What should a method be? - CORRECT ANSWER A step-by-step set of instructions, Be logically ordered, allows you to take sensible measurements, and allows you to test your hypothesis.
When planning your method what do you need to make sure? - CORRECT ANSWER That it will procedure a range of results, reliable results, precise results, and accurate results.
What are some types of data? - CORRECT ANSWER The data can be continuous such as the age of plant ir number of plants. Some data can be a mixture of numbers and names such as the number of different types of plants found in a garden.
What data is normally displayed on a bar chart? - CORRECT ANSWER Continuous data. You need to make sure its a smooth curve of best fit, and that the curve goes through or near most of the points.
What are bar charts used for? - CORRECT ANSWER They are used for discrete data but can be used to compare different sets of data.
What is the Pattern on the graph? - CORRECT ANSWER The shape of the graph. It is the line that goes up as time goes by but eventually levels off
What is the trend on a graph? - CORRECT ANSWER The relationship between factors on the graph or in the table. The full trend is that the volume increases as the time increases but then levels off after a certain amount of time.
What is the sample size? - CORRECT ANSWER The number of people sampled in the investigation. To be confident in your conclusions you need a large sample size to give strong evidence.
What is Primary data? - CORRECT ANSWER This is the data that you have gathered for yourself through the experiments or investigations .
What is secondary data? - CORRECT ANSWER The data that you get in books, scientific papers or the internet. You should compare your primary and secondary data to draw a conclusion
How do you know if the data is anomalous? - CORRECT ANSWER It doesn't fit into the pattern of the other results. It does not lie close to the line of best fit.
What can cause the anomalous data? - CORRECT ANSWER Not following the method correctly. inaccurate measuring/recording and impurities.
What is systemic error? - CORRECT ANSWER The error that is built into the method or equipment which you are using. This can be corrected by calibrating the balance. These errors are quantitative.
What is the random error? - CORRECT ANSWER These are due to not following the method correctly and can be minimized by repeating results and taking averages.
What can misreading the observations cause - CORRECT ANSWER They can cause qualitative errors.
What is the accuracy? - CORRECT ANSWER How close is the data to the true value? Errors due to the equipment could make the results less.
What is the reliability? - CORRECT ANSWER How trustworthy the data is. It is usually ensured by repeating the readings to identify any anomalous results.
What is precision? - CORRECT ANSWER How close the repeat readings are to each other. It can be improved by using measuring equipment that measure to more decimal places.
What is an enzyme? - CORRECT ANSWER A protein molecule that acts as a catalyst in a biochemical reaction.
What are proteins made up of? - CORRECT ANSWER amino acids
What four chemical groups are attached to the central (alpha) carbon? - CORRECT ANSWER A hydrogen atom. A amino acid. A carboxyl group. A variable R group (side chain).
How many different R groups are there? - CORRECT ANSWER There are 20 different R groups which means there are 20 different amino acids.
What are amino acids linked together by? - CORRECT ANSWER Peptide Bonds.
What does a condensation reaction occur between? - CORRECT ANSWER Two amino acids.
What is produced in a condensation reaction? - CORRECT ANSWER Water.
What is a dipeptide formed by? - CORRECT ANSWER Two amino acids linked by a peptide bond.
What do three amino acids form? - CORRECT ANSWER A tripeptide
What do many amino acids join to form? - CORRECT ANSWER A polypeptide
What is a polypeptide with more than 50 amino acids called? - CORRECT ANSWER A protein.
What is an active site? - CORRECT ANSWER The part of an enzyme where the biochemical reaction takes place.
What is a secondary structure? - CORRECT ANSWER Where a polypeptide chains form orderly shapes.
What are secondary structures held in shape by? - CORRECT ANSWER Hydrogen bonds between the -NH of one of the peptide link and the -C=O of another amino acid
What is tertiary structure? - CORRECT ANSWER a three dimensional shape of a secondary structure
What does the tertiary structure give? - CORRECT ANSWER It gives the enzyme the shape of its active site.
What are the most common shapes of secondary structures? - CORRECT ANSWER Coiled α-helix and folded β-pleated sheet
What does the active site consist of? - CORRECT ANSWER A small number of amino acids which form a specific shape because of the proteins secondary and tertiary structure.
When an enzyme catalyzes a reaction where does it take place? - CORRECT ANSWER It takes places on the active site of an enzyme.
What do enzymes work specifically to? - CORRECT ANSWER catalyse one type of biochemical reaction.
In a biochemical reaction what are substrates converted to? - CORRECT ANSWER They are converted into products.
What does the substrate bind to? - CORRECT ANSWER The active site. Only specific substrates will bind to a particular enzymes site.
What shape does the substrate have? - CORRECT ANSWER They have a complementary shape to the shape of the active site on the enzyme.
What happens after the reaction? - CORRECT ANSWER The product is released and the active site is available to catalyse further reactions.
The active site is a specific shape that only the substrate will fit, What happens to the active site is the temperature goes too high? - CORRECT ANSWER The temperature is too high, the hydrogen bond will break. This means the enzyme changes its shape so the active site loses its shape. The enzyme is denatured and co no longer act as a catalyst.
What is a catalyst? - CORRECT ANSWER It is a substance that speeds up a reaction. It can take part in the reaction but is left unchanged at the end of the reaction.
What catalysts are enzymes? - CORRECT ANSWER They are biological catalysts.
What is the collision theory? - CORRECT ANSWER For a reaction to occur, the particles must collide and the particles must have enough energy to react.
What dos the energy of the collision depend on? - CORRECT ANSWER It depends on the speed of the particle and the angle they collide.
What is the activation energy? - CORRECT ANSWER The minimum energy needed for particles to react.
Why does the enzyme lowers the activation energy needed? - CORRECT ANSWER The more particles have the required energy to react. There are more successful collisions. And there is a faster reaction.
What is the catalytic activity? - CORRECT ANSWER The increase in the rate of a reaction caused by the inclusion of an enzyme.
What is the substrate? - CORRECT ANSWER The molecule that is affected by the activation of the enzyme.
What is the active site? - CORRECT ANSWER The area of an enzyme where a substrate binds.
What does denatured mean? - CORRECT ANSWER When the tertiary structure of the enzyme is changed.
How can enzyme reactions be measured? - CORRECT ANSWER They can be measured by measuring a decrease in the substance. By measuring the increase in the product, this makes is easier because you know the starting measurement for the product will be 0.
Why must the initial rate of reaction be recorded? - CORRECT ANSWER It needs to be measured because the rate will decrease as the substrate is used up and its concentration decreases.
What does the enzyme need, in order to work effectively? - CORRECT ANSWER Specific conditions.
What happens if the specific conditions are not present? - CORRECT ANSWER The enzyme-catalysed reaction may slow down or might not work at all
What is the optimum temperature? - CORRECT ANSWER Each enzyme has a optimum temperature at which it works fastest.
What happens as the temperature increases to the optimum temperature? - CORRECT ANSWER The reaction rate also increases.
What happens below the optimum temperature? - CORRECT ANSWER There is less energy which means there is fewer collisions and therefore a slower reaction.
What happens above the optimum temperature? - CORRECT ANSWER The hydrogen bonds in the enzyme breaks and the enzyme and active site loses its shape and therefore there is no catalysis
What do enzymes have? - CORRECT ANSWER An optimum pH
What does pH affect on the active site? - CORRECT ANSWER The charge. If the pH changes then the charges on the active site changes ad the substrate may no longer be able to bind to it
What can the concentration of the enzyme and substrate affect? - CORRECT ANSWER The rate of reaction.
What happens if the concentration of the substrate is too high? - CORRECT ANSWER There will be no more active sites for them to bind to. Increasing the concentration of the substrate will no longer affect the rate of reaction
What happens if the concentration of the enzyme is too high? - CORRECT ANSWER There are too many free available active sites compared to the substrate molecules, the rate of reaction no longer increases.
What is diffusion? - CORRECT ANSWER Diffusion is the movement of substances from a region of high to low concentration.
What can diffusion occur across? - CORRECT ANSWER It can occur across a membrane. As long as the molecules are small enough to pass through the membrane then diffusion will occur
What factors affect the rate of diffusion? - CORRECT ANSWER Size- The larger molecules move more slowly then smaller ones, so the rate of diffusion decreases.
Temperature- A higher temperature increases the energy molecules have and so they move faster, increasing the rate of diffusion.
Distance through a substance- The greater the distance that the molecules must travel through a substance, the slower the rate of diffusion.
Surface area- As surface area increases, the area of which molecules cans spread is increased and so he rate of diffusion increases.
Shape of the surface of which the molecule is diffusing- the shape of the surface of which the molecule is diffusing can affect the rate of diffusion.
What does the kinetic theory explain? - CORRECT ANSWER It explains the properties of different states of matter. It also explains diffusion
What is the arrangement of particles in a solid? - CORRECT ANSWER They are close together in a regular pattern.
What is the arrangement of particles in a liquid? - CORRECT ANSWER They are close together in a random pattern.
What is the arrangement of particles in a gas? - CORRECT ANSWER They are far apart and in a random pattern.
What are the properties of solids? - CORRECT ANSWER They are in a fixed shape and they cannot flow. They cant be compressed or squashed.
What are the properties of liquids? - CORRECT ANSWER They take shape of a container, they flow and move randomly. They cannot be compressed or squashed.
What are the properties of gases? - CORRECT ANSWER They completely fill container and they can flow and move randomly. They can be compressed or squased.
Where can diffusion happen within? - CORRECT ANSWER A mixture of liquids, a mixture of gases, and a mixture of liquids and gases.
How do humans improve the growth of crops? - CORRECT ANSWER They correct soil pH, optimum watering. Correct nutrients present
How can humans have a negative effect on plant growth? - CORRECT ANSWER Trampling. Picking wildflowers. Removing hedges/tress.
How can humans have an effect of the distribution of plants? - CORRECT ANSWER Sowing crops means field with only one type of plant. Trampling can cause unusual or more widespread distribution patterns due to seeds being carried on the bottom of shoes.
What pH doe plants grow best at - CORRECT ANSWER Between 4.5 and 7.5
What does acidic soil mean? - CORRECT ANSWER It can mean that there is a deficiency in necessary minerals, such as iron and manganese.
Why is Soil Aeration necessary? - CORRECT ANSWER It is necessary to allow sufficient oxygen to get to the plant and for carbon dioxide to be removed.
What forms when there is little aeration? - CORRECT ANSWER Toxins form such as hydrogen sulfide gas.
Why is temperature important in plants? - CORRECT ANSWER Most plants have a optimum temperature they will grow at. The temperature is important for seed germination, seeds need the soil to be within a specific temperature range in order for them to germinate.
What three things are important for plant growth? - CORRECT ANSWER Light, water and minerals.
Why do plants need light? - CORRECT ANSWER They need light for photosynthesis. Plants in high light intensity are more likely to grow better than those in shade. Plants that are used to low light intensity may get scorched in the sun.
What happens if there is not enough soil moisture? - CORRECT ANSWER The rate of photosynthesis decreases. Plants cannot take up necessary minerals and nutrients.
What are the effects of too little rainfall in plants? - CORRECT ANSWER Yellow leaves, dry leaves and ground cracks
What are the effects of too much rainfall in plants? - CORRECT ANSWER Yellow leaves, Rotted roots, minerals and nutrients washed away and soil erosion.
How do plants take up mineral ions? - CORRECT ANSWER Through their roots
What does random sampling mean? - CORRECT ANSWER It means that each potential sample has the same probability of being selected.
When is random sampling used? - CORRECT ANSWER When the area under the study is large. When it is fairly uniform and when there is limited time.
What can piolet study's do? - CORRECT ANSWER They can help you work out your sampling size.
What is the minimum sample size? - CORRECT ANSWER The minimum sample size is the number of samples at which the number of different species found starts to level off
What Abiotic factors can affect plant population? - CORRECT ANSWER The soil type/ moisture/ pH. Topography, for example steepness of slopes. Temperature.
What is a quadrat? - CORRECT ANSWER A quadrat is a small area of habitat, which sometimes has a grid within it. The frame is placed in the ground and the plants and animals inside are counted.
What is a point frame? - CORRECT ANSWER It contains a number of pins.
What is a line transects? - CORRECT ANSWER Sampling lines are set up across the area to be sampled. Species can be recorded along the whole length of the line, this is continuous sampling. Or when species can be recorded at set intervals along the line, this is systemic sampling.
What is a belt transcet? - CORRECT ANSWER It is similar to a line transect but it gives information on the abundance of species. Quadrats are placed at set intervals along the line and numbers of each species are counted within them
What do you need to consider when investigating fuels? - CORRECT ANSWER How much energy they produce, What pollutants they produce and how a fuel is chosen for specific purposes.
What is the reaction for combustion of fuels? - CORRECT ANSWER It is exothermic, therefore energy is releases as heat.
What is the word equation for combustion? - CORRECT ANSWER Fuel + Oxygen -> Carbon dioxide + Water
(+ heat energy)
What is flammability? - CORRECT ANSWER It is one of the most useful properties of fuels as itshow easily they catch fire. This can be a hazard and should be treated like it.
What is toxicity? - CORRECT ANSWER Fuels can carry impurities that are toxic.
What does sulfur dioxide react with to produce acid rain? - CORRECT ANSWER They react with moisture in the air.
What does acid rain do? - CORRECT ANSWER It erodes limestone buildings and statues. It acidifies lakes and rivers. It kills aquatic plants and animals.
What happens if there is limited oxygen in combustion? - CORRECT ANSWER Incomplete combustion occurs which can produce carbon monoxide and soot.
What is the wordequation for incomplete combustion? - CORRECT ANSWER Fuel + Oxygen -> carbon monoxide + water (+ Heat energy)
What is carbon monxide? - CORRECT ANSWER It is a poisonous gas and can cause headaches, dizziness, nausea and death.
What is the word equation for soot? - CORRECT ANSWER CH4 + O2 -> C =+ 2H2O
What units is energy measured in? - CORRECT ANSWER They can be measured in different units, Mainly joules.
What is specific heat capacity of water? - CORRECT ANSWER When 4.2 joules of energy to raise the temperature of 1g of water by 1 degree c.
Converting units - CORRECT ANSWER 1 kilojoule (KJ) = 1000 Joules (J)
1 kilometer (KM) = 1000 Meters (m)
1 Kilogram (KG) = 1000 grams (g)
1 kilocalorie (Kcal) = 1000 calories (cal)
How can you investigate the energy in food or fuel? - CORRECT ANSWER You can investigate the energy in food or fuel by burning the food or fuel under a certain volume of water using a calorimeter.
What is the equation for Heat energy? - CORRECT ANSWER Heat energy (J) = Mass of water (g) X specific heat capacity of water (Jg-1C-1)
How can energy be calculated? - CORRECT ANSWER Heat of combustion (kJ mol-1)= ((heat energy to water (kJ) x relative molecuar mass of fuel)) / Mass of fuel burnt (g)
What is a battery in a circuit? - CORRECT ANSWER Made up of more than one cell.
What is an ammeter in a circuit? - CORRECT ANSWER It measures current that flows through a component in a circuit. It is placed in series with the component
What is a voltmeter in a cirucit? - CORRECT ANSWER It measures the voltage across a component in a circuit. It is placed in parallel with the component
Bulb in a circuit - CORRECT ANSWER
What is a resistor? - CORRECT ANSWER It controls the current in a circuit.
What is a variable resistor? - CORRECT ANSWER It is used to change the current in a circuit. It goes in series in the circuit
What is a diode? - CORRECT ANSWER It only allows current to flow one way through a circuit. It is in series in the circuit
What is power? - CORRECT ANSWER Power is the rate of doing work? It is the amount of energy consumed per unit of time.
What can power refer to? - CORRECT ANSWER It can refer to physical work or electrical power.
What does the work done equal - CORRECT ANSWER Work done = The amount of energy supplied or transformed.
What is the equation for electrical power? - CORRECT ANSWER power = voltage x current. p=VI
What is the equation for physical power? - CORRECT ANSWER Power = work done/ time (P=W/t)
What is a fuse? - CORRECT ANSWER A fuse is a component of a circuit that will 'blow' if there is a fault in the circuit [Show Less]