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Pearson GCSE Separate Science Biology
| Question | Answer |
|---|---|
| What does a microscope do? | (makes small objects appear larger/magnifies small objects) |
| What part of a microscope do you look through? | (eyepiece lens) |
| Which part of a microscope do you use to get a clear image? | (the focusing wheel) |
| If an average height person in Year 10 is magnified 600 times, how tall will they be compared to the tallest building in the world, which is 828 m tall? | (about the same height; the Burj Khalifa, Dubai is 828 m tall) |
| Put these in order of size, biggest first: atom, animal cell, cell nucleus, muscle tissue, protein molecule, water molecule | (muscle tissue, animal cell, cell nucleus, protein molecule, water molecule, atom) |
| A microscope has a ×5 eyepiece lens and a ×5 objective lens. What is the total magnification? | (×25; 5 × 5 = 25) |
| A human hair has a width of 100 µm but appears 20 mm wide in a photo. What magnification is the photo? | (×200; 20 mm = 20 000 µm; 20 000 ÷ 100 = 200) |
| How many millimetres are there in a metre? | -1000 |
| What is the unit symbol for a nanometre? | (nm) |
| What unit is 1000 times smaller than a millimetre? | (micrometre, µm) |
| What is an estimation? | (an approximate value) |
| Name one part you could find in a plant cell but not an animal cell. | (cell wall, chloroplasts, permanent vacuole) |
| What process happens in a mitochondrion? | (aerobic respiration) |
| What is one function of a plant cell’s permanent vacuole? | (to help keep the cell rigid/to store substances) |
| In which part of a plant cell is cell sap stored? | (vacuole) |
| In which part of a cell would you find chromosomes? | In which part (nucleus) |
| When you look down a microscope, what is the area that you see called? | (field of view) |
| Why can an electron microscope detect smaller structures in cells than a light microscope? | (it has better magnification and better resolution) |
| What is a picture taken with a microscope called? | (micrograph) |
| Some microscope pictures have a small line drawn on them with information about how long the line is when unmagnified. What is this line called? | (scale bar) |
| List three sub-cellular structures that are usually found in animal cells. | (any three from: cell membrane, nucleus, mitochondria, ribosomes) |
| List three sub-cellular structures found in plant cells but not in animal cells. | (large permanent vacuole, chloroplasts, cell wall) |
| Which cell structure controls what enters and leaves the cell? | (cell membrane) |
| Which cell structure controls how the cell works? | (nucleus) |
| In which cell structure does respiration mainly take place? | (mitochondria) |
| Which plant cell structure contains chlorophyll? | (chloroplast) |
| What is the function of the cell structure that contains chlorophyll? | (to capture energy from light for photosynthesis/to produce glucose using photosynthesis) |
| Describe the function of the structure that surrounds plant cells, but not animal cells. | (supports and protects the cell) |
| What is the function of ribosomes? | (manufacture of proteins) |
| What are gametes? | (sex cells) |
| A bacterium is 20 µm long. How long is it in metres? | (0.00002 m) |
| A bacterium is 5 µm wide. How wide is it in nanometres? | (5000 nm) |
| What part of an animal cell controls the cell’s activities? | (nucleus) |
| What do ribosomes make? | (proteins) |
| Name one part that a plant cell might have but an animal cell would not. | (chloroplast, permanent large vacuole, cell wall) |
| What do bacteria use to move themselves? | (flagella) |
| Animal and plant cells are eukaryotic. What word describes bacterial cells? | (prokaryotic) |
| Name one structure that an animal cell would have but a bacterial cell would not. | (nucleus, mitochondria) |
| What is this format for numbers called: A × 10n? | (standard form) |
| What is 1 × 106 m written as an ordinary number? | (1 000 000 m) |
| Name two substances that might be found in the cytoplasm of an egg cell to provide energy. | (carbohydrate or starch, lipid or fat or oil) |
| Egg cells also contain protein. Which cell structure makes proteins? | (ribosome) |
| In which system of the body is food broken down? | (digestive system) |
| Why do we need to break food down? | (because the molecules in food are too large to cross cell membranes) |
| In which organ of the body is digested food absorbed? | (small intestine) |
| Which group of molecules help to digest food? | (enzymes) |
| Give one example of an enzyme | (any suitable example, such as amylase, protease, lipase) |
| What does a sperm cell use enzymes for? | (to digest a path through the jelly coat of the egg cell) |
| Do plants contain enzymes? | (yes – they control many reactions inside plant cells) |
| Is starch an example of a carbohydrate, a protein or a lipid? | (carbohydrate) |
| Why are proteins and carbohydrates examples of polymers? | (They are made up of many similar molecules/monomers) |
| Which monomers make up starch? | (glucose) |
| Which monomers make up a protein? | (amino acids) |
| Are enzymes carbohydrates, proteins or lipids? | (proteins) |
| Which group of substances are fats and oils examples of? | (lipids) |
| Name one food that contains a lot of starch. | (any suitable example such as: potato, pasta, bread, rice) |
| What effect does the enzyme amylase have on starch? | (breaks it down to small sugars/maltose) |
| Food provides nutrients for growth. What else is it a source of, which we need for activity? | (energy) |
| Which cell structures break down molecules from food to release energy? | (mitochondria) |
| Name a part of a plant where you might find enzymes. | (anywhere a reaction takes place, e.g. in chloroplasts for photosynthesis, in mitochondria for respiration, where starch grains are made) |
| What are the subunits (small molecules) that make up carbohydrates? | (simple sugars, e.g. glucose) |
| Which two kinds of subunits form lipids (fats and oils)? | (fatty acids and glycerol) |
| Which kind of large biological molecule are enzymes? | (proteins) |
| Which subunits make up enzymes? | (amino acids) |
| Amylase is a kind of enzyme. Where is it found in humans? | (mouth/salivary glands and small intestine/pancreas) |
| What is a substrate? | (The molecule that an enzyme joins with at the start of a reaction.) |
| Why are enzymes called biological catalysts? | (They are molecules found inside living organisms that speed up the rate of reactions.) |
| What does ESC stand for? | (Enzyme substrate complex) |
| What is the substrate for amylase? | (starch) |
| Starch synthase is an enzyme that catalyses the synthesis of starch. Explain what this means. | (The enzyme joins together small sugar molecules to form starch.) |
| What are the subunits of enzymes? | (amino acids) |
| Why do different enzymes have different 3D shapes? (The enzyme joins together small sugar molecules to form starch.) | (The amino acids are arranged in a different order in different proteins.) |
| Which kind of large organic molecule does a protease digest? | (proteins) |
| Which kind of enzyme would break down a food stain made by sunflower oil? | (lipase) |
| What is the name of the part of an enzyme into which the substrate fits? | (active site) |
| Why do most enzymes only work with one substrate? | (Only substrates with the same shape as the Active site can sit in the site and take part in the reaction.) |
| Enzymes are specific to their substrate. What does this mean? | (The enzyme will only work with particular substrates – those substrates that have the right shape.) |
| Which term describes an enzyme in which the active site has permanently changed shape? | (denatured) |
| What effect does a large change of shape of an enzyme's active site have on how the enzyme works? | (The enzyme no longer works.) |
| Give two examples of changes in the cell environment that could cause the active site to change shape. | (pH, temperature) |
| Which cell structure surrounds every kind of cell? | (cell surface membrane) |
| What is the function of this cell structure? | (to control what enters and leaves the cell) |
| Name one gas that a cell needs to take in from its surroundings, and explain your answer. | (oxygen needed for respiration/to release energy in mitochondria; carbon dioxide needed for |
| Name one other substance that a cell needs to take in from its surroundings, and explain your answer | (any suitable answer, such as glucose/sugar needed for respiration) |
| Carbon dioxide is produced inside a cell and moves out of the cell by diffusion. What does this mean? | (there is an overall movement of gas particles from where there are more of them to where there are fewer) |
| Name one other substance that is made inside a cell and leaves the cell. | (any suitable substance, such as enzymes or hormones that are secreted) |
| Name two substances that plants take in from the soil through their roots. | (water and dissolved mineral salts) |
| There is a 5% sucrose solution and a 10% sucrose solution. Which solution has the higher concentration of sucrose? | (10% solution) |
| Two beakers contain the same volume of solution. One is a 10% sodium chloride solution, the other is a 5% sodium chloride solution. Which beaker contains more water molecules? | (5% solution) |
| Digested food substances are absorbed from the small intestine into the body. At the start of this process, in which place are they in highest concentration – in the body or in the small intestine? | (small intestine) |