Download AQA Knowledge test ANSWERS Unit 2 Biology B2.1_Cells and

AQA Knowledge test ANSWERS Unit 2 Biology
B2.1_Cells and Simple cell transport B2.1.1 Cells and cell structure 1. What are the main parts of animal cells? Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes 2. Which parts of a cell are found in plant cells but not animal cells? Cell wall, chloroplasts, permanent vacuole 3. Name the parts of bacterial cells? Cytoplasm, ribosomes, genes (that are not a distinct nucleus) and a cell membrane surrounded by a cell wall. 4. Name the parts of yeast cells contain? Nucleus, cytoplasm and a membrane surrounded by a cell wall. 5. What is the function of a nucleus of a cell? To control the activities of the cell and to store the genetic information. 6. If a cell has adapted to do a particular function, what is it said to be? Specialised 7. What is the function of cytoplasm? To provide a place for most of the chemical reactions to take place. 8. What is the function of a cell membrane? To control the passage of substances into and out of the cell. 9. What is the function of mitochondria? To provide a place for most of the energy in respiration to be released. 10.Where does protein synthesis in the cell happen? Ribosomes 11.Which feature do plant cells have which help them to strengthen their cells? They have cell walls made of cellulose 12.What is the function of the chloroplasts? They absorb light energy to make glucose (carry out photosynthesis) 13.What is found inside the permanent vacuole of plant cells? Cell sap 14.What is important about the genetic information in a bacterial cell? It is not inside a distinct nucleus 15. What part is missing from a red blood cell? A nucleus 16.Name two features of a sperm cell. Tail, lots of mitochondria, enzymes in the head, single set of chromosomes 17.What is the function of the goblet cell? Produce mucus 18.Where in the body do you find goblet cells? Digestive system and lungs 19.Why do cilia and sperm have lots of mitochondria? They move a lot so need lots of energy. PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.1.2 Dissolved substances 1. How do dissolved substances move in and out of cells? Through cell membranes by diffusion 2. What is the definition of diffusion? Diffusion is the spreading of the particles of a gas or of any substances in solution from a region of higher concentration to a region of lower concentration. 3. What will affect the rate of diffusion? Temperature and concentration 4. What is a concentration gradient? A difference in concentration between two areas next to each other. 5. Name two locations in the body where diffusion is important. Lungs and small intestines 6. Which important gas passes through cell membranes into cells? Oxygen PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.2_Tissues, organs and organ systems B2.2.1 Animal organs 1. What does multicellular mean? An organism with a number of cells which work together to carry out functions. 2. What is a tissue? A group of cells with similar structure and function which work together to carry out a particular function e.g. muscle 3. What is an organ? Different types of tissue which work together to carry out a function e.g. the heart. 4. What is an organ system? A group of organs all working together to carry out a particular function. 5. What is the function of muscular tissue? To contract and relax to bring about movement. 6. What is glandular tissue? A tissue which produces substances such as enzymes and hormones (e.g. ovary) 7. What is epithelial tissue? A tissue which covers some parts of the body (lining of the body) 8. Which 3 main tissues does the stomach contain? Muscular tissue (to churn food), glandular tissue (to produce digestive juices) and epithelial tissue (to cover the outside and inside of the stomach) 9. Complete the following table for parts of the digestive system, name the parts. Part(s) Function
Stomach Digests food Liver Produces bile
Large intestine Absorbs water/ produces faeces
Small intestine Digest and absorb soluble food
Pancreas/ salivary glands Produce digestive juices
PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.2.2 Plant organs 1. What are the 4 main organs of plants? Roots, stems, flowers and leaves 2. What tissue are plants covered in? Epidermal 3. Which tissue is responsible for carrying out most photosynthesis? Mesophyll 4. Which tissue transports water around the plant? Xylem 5. Which tissue transports sugars around the plant? Phloem 6. What tissue allows gases in and out of a plant leaf? Stomata 7. Label parts A‐E. A – Waxy layer B – Upper epidermis C – Palisade cell D – Spongy Cell E ‐ Stomata PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.3.1 Photosynthesis 1. What are the reactants needed for photosynthesis? Water and Carbon dioxide 2. What are the products of photosynthesis? Glucose and oxygen 3. Which type of energy is essential for photosynthesis to take place? Light energy 4. Which organelle (part of a cell) carries out photosynthesis? Chloroplast 5. What is the name of the green substance which captures light energy (and is found in chloroplasts) to enable photosynthesis? Chlorophyll 6. Where does the water, required by plants, come from? The soil 7. What three factors can limit the rate of photosynthesis? Light, CO2, Temperature 8. How is glucose used by plants and algae? (There are a number of ways.) Used in respiration, used to produce fat, oil, cellulose (which strengthens cell walls) and proteins 9. What else do plants need to absorb from the soil to produce proteins? Nitrate ions 10.What do plants store starch as? Insoluble starch 11.List three things you can do in a greenhouse to increase growth. Artificial light ‐ allows photosynthesis to continue Heating ‐ allows photosynthesis to continue at an increased rate heater can also give off extra carbon dioxide released. PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.4.1 Distribution of organisms 1. Which six physical factors affect organisms? Temperature, availability of nutrients, amount of light, availability of water, availability of oxygen and availability of carbon dioxide 2. What is a quadrat? These are square frames, used to mark off specific areas of ground 0.5m X 0.5m 3. Which two methods can be used to collect quantitative data on the distribution of organisms? Random sampling using quadrats and sampling along a transect 4. How can you make sure you place the quadrats at random? Use a calculator to generate random numbers. 5. Why should a large sample size be used when sampling data? To make the results more valid (you can calculate a mean, identify anomalous results, look for patterns, etc) 6. What is another term for non‐living factors? Abiotic 7. What is another term for living factors? Biotic PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.5 Proteins – their functions and uses B2.5.1 Proteins/B2.5.2 Enzymes 1. Which molecule are proteins made from? Amino acids 2. What happens to the long chains formed by these molecules? They are folded up into a specific shape 3. What do proteins act as? Structural components of tissues (e.g. muscles), hormones, antibodies and catalysts. 4. What do catalysts do? The increase the rate of chemical reactions 5. What are biological catalysts called? Enzymes 6. Which type of molecule are enzymes made from? Proteins 7. What property of enzymes is vital for its function? The shape of the enzyme molecule 8. What do high temperatures do to enzymes? The shape of the enzyme molecule 9. What other factor is important for enzymes to function correctly? pH 10.What does denatured mean? When the active site of an enzyme changes shape. 11.Which two enzymes are present in biological detergents (washing powders)? Proteases and lipases 12.How does having enzymes in biological detergents help them to perform better? They are more effective at low temperatures (high temperatures will denature the enzymes in them) 13.How are proteases used in industry? To pre‐digest baby food (making it easier for babies to digest their food) 14.How is isomerase used in industry? To convert glucose syrup into fructose syrup, which is much sweeter, and therefore can be used in smaller quantities in slimming foods. PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.5.2 Enzymes 1. Where are digestive enzymes produced? By specialised cells in glands and the lining of the gut. 2. What is the general function of digestive enzymes? They breakdown large molecules into smaller molecules. 3. Where is the enzyme amylase produced? In the salivary glands, the pancreas and the small intestine. 4. What does amylase do? It catalyses the breakdown of starch into sugars in the mouth and small intestine. 5. Where is the enzyme protease produced? In the stomach, the pancreas and the small intestine. 6. What does protease do? It catalyses the breakdown of proteins into amino acids in the stomach and small intestine. 7. Where is the enzyme lipase produced? In the pancreas and small intestine. 8. What does lipase do? It catalyses the breakdown of lipids (fats and oils) into fatty acids and glycerol in the small intestine. 9. What conditions do the enzymes in the stomach work best in? Acidic 10.Approximately what is the pH of the acid in the stomach? pH 2 11.Where is ‘bile’ produced? The liver 12.What does bile do? It acts in the small intestine to neutralise the acid from the stomach. 13.Do enzymes in the small intestine prefer alkaline or acid conditions? Alkaline (this is why the bile is added to neutralise the acid, it also makes the solution slightly alkaline) 14.Name 3 processes where enzymes work inside cells. Enzymes for respiration, photosynthesis and protein synthesis work inside cells PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.6_Aerobic and anaerobic respiration B2.6.1 Aerobic respiration 1. What are chemical reactions inside the body controlled by? Enzymes 2. What are the reactants of aerobic respiration? Glucose and oxygen 3. What are the products of aerobic respiration? Carbon dioxide and water (and energy) 4. Where, in the cell, do most of the reactions in aerobic respiration take place? Mitochondria 5. How is energy produced by respiration used by ALL organisms? To build larger molecules from smaller ones 6. How is energy produced by respiration used by mammals and birds? To maintain a steady body temperature in colder surroundings 7. How is energy produced by respiration used by plants? To build up sugars, nitrates and other nutrients into amino acids which are then used to make proteins 8. What are the two main ways the body responds during exercise? Increased heart rate and rate and depth of breathing increases 9. Why does the body respond to exercise in this way? To increase blood flow to muscles, so increase glucose and oxygen supply to them (increasing rate of respiration so more energy is produced) and increase the rate of removal of carbon dioxide. PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.6.2 Anaerobic respiration 1. Which substance do muscles store glucose as? Glycogen 2. What happens to the stored glucose in muscles during exercise? Converts glycogen to glucose 3. Why do muscles carry out anaerobic respiration? If too little oxygen is reaching them during exercise 4. How does the breakdown of glucose differ in aerobic and anaerobic respiration? Anaerobic respiration is the incomplete breakdown of glucose 5. What is the product of anaerobic respiration? Lactic acid 6. How does the amount of energy produced differ in aerobic and anaerobic respiration? Less is produced in anaerobic 7. HT ‐How is the oxygen debt produced by anaerobic respiration repaid? Lactic acid is oxidized (using oxygen) to carbon dioxide and water 8. Why do muscles become fatigued? If they are subjected to long periods of vigorous activity 9. What does ‘fatigued’mean? Muscles stop contracting efficiently 10.What is one of the causes of muscle fatigue? The build‐up of lactic acid 11.What is fermentation? The anaerobic respiration in yeast it produces ethanol and carbon dioxide PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.7 Cell division and inheritance B2.7.1 Cell division 1. How are chromosomes normally arranged in body cells? In pairs 2. What is the name of the type of cell division seen in body cells? Mitosis 3. What do chromosomes contain? Genetic information 4. What first happens to the genetic material when a body cell divides? It is copied 5. How many times does a body cell divide? Once 6. How does the genetic information of a new cell, produced by a body cell dividing, compare with the original cell? They are identical 7. How many sets of chromosomes does a human body cell have? Two 8. How many sets of chromosomes do sex cells have? One 9. What is another name for ‘sex cells’? Gametes 10.What is the name of the type of cell division that produces gametes? Meiosis 11. HT‐ What first happens to the genetic material when a cell divides to form gametes? Copies of the genetic material are made. 12. HT ‐ How many divisions does an original cell go through to produce sex cells? Two 13. HT ‐ How many gametes are formed after one original cell divides? Four 14. HT ‐ How many sets of chromosomes do these gametes contain? One 15. HT ‐ How does the genetic information of gametes compare to the original cell? They have half of the information 16.What happens to at fertilisation? Gametes join to form a single body cell with a new pair of chromosomes. 17.What type of cell division happens once and egg has been fertilised? Mitosis 18.Why do mature animal cells divide? To repair and replace old cells PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards 19.Where do human stem cells come from? Embryos and adult bone marrow 20.What can human stem cells have the ability to do? Develop into any type of human cell 21.When do animal cells differentiate compared to plant cells? Animal cells differentiate at early stages, whereas many plant cells retain the ability to differentiate throughout life. 22.How many pairs of chromosomes are there in a human body cell? 23 pairs PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.7_Cell division and Inheritance B2.7.2 Genetic variation 1. How does sexual reproduction give rise to variation? Reproduction without the need for fertilisation (mitosis from a single cell) 2. How are inherited characteristics controlled? Some are controlled by a single gene, others are controlled by a number of genes. 3. What is an allele? A different form of a gene 4. What is a dominant allele? An allele which controls a characteristic when it is present on only one of the chromosomes in the pair 5. What is a recessive allele? An allele which controls the development of characteristics only if the dominant allele is not present. 6. Which molecule are chromosomes made from and what is its structure like? DNA 7. What is a gene? A small section of DNA 8. What does a gene contain? The genetic code for a particular sequence of amino acids which makes a specific protein. 9. What does DNA fingerprinting tell us? Each person has a unique DNA which can be used to identify individuals. 10.What are the female sex chromosomes? XX 11.What are the male sex chromosomes? XY 12.HT ‐ What is a monohybrid cross? A cross (joining of gametes) between organisms which looks at only one allele at a time. 13.HT ‐ What does homozygous and heterozygous mean? Homozygous means both alleles which code for a particular protein are the same (bb or BB), heterozygous means alleles are different (Bb). 14.HT ‐ What does genotype mean? A description of the alleles present. e.g. Bb 15.HT ‐ What does phenotype mean? A description of the observed characteristic e.g. brown hair. 16.What are genetic disorders? Disorders which are inherited due to mutations in genes. 17.What is ‘polydactyly’? When a person is born with extra digits (fingers and/or toes). PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards 18.How is polydactyly inherited? It is caused by a dominant allele and can be passed on by only one parent who has the disorder. 19.What is cystic fibrosis? A disorder of cell membranes which makes patients produce more mucus (particularly in lungs) than normal. 20.How is cystic fibrosis inherited? It is a recessive disorder so both parents must be carriers of the cystic fibrosis allele. 21.What does a ‘carrier’ mean? Someone who has the allele for a disorder but does not have the disorder themselves. Carriers can only be present in inherited disorders which are recessive. 22.How can you carry out screening for these disorders? You can screen embryos for the alleles of genetic disorders. 23.What is a generic pedigree? A diagram that shows who in a family have a genetic disorder, are carriers and are normal. 24.What ideas did Mendel propose and why was this discovery not recognised until after his death? They did not take him seriously and knew nothing about genes. 25.Which organism did Mendel carry out most of his research on? He looked at pea plants. PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards B2.8_Speciation B2.8.1 Old and new species 1. Where does evidence for early forms of life come from? Fossils 2. Why are scientists not certain about how life began on Earth? Because early forms of life did not leave much fossil evidence, they did not have bones and may have been disrupted by the Earth’s natural movements. 3. What is a fossil? The ‘remains’ of organisms from many years ago, found in rocks. 4. How are fossils formed? 1. From the hard parts of animals that do not decay easily. 2. From parts of organisms that have not decayed because one or more of the conditions needed for decay are absent e.g. oxygen. 3. What parts of the organism are replaced by other materials as they decay. 4. As preserved traces of organisms e.g. footprints, burrows and faeces. 5. What can we learn from the fossil record? How much or little organisms have changed as life developed on Earth. 6. How might extinction be caused? By changes to the environment, new predators, new diseases, new and more successful competitors, a single catastrophic event 7. HT ‐ What is speciation? When an isolated population becomes so different from the original population that a new species is produced. 8. HT ‐ Describe the process of natural selection. Variation –populations of organisms have variations. Over‐production –produce more young than will survive to adulthood. Struggle for existence – competition for survival between the organisms Survival – those with advantageous characteristics are more likely to survive Advantageous characteristics inherited – better adapted organisms are more likely to reproduce successfully passing on the advantageous characteristics to their offspring in their genes. Gradual change – over a period of time the more individuals with the advantageous characteristics in the population. PiXL AQA Knowledge Test ANSWERS Unit 2 Biology 2 B2 GCSE Additional Science for certification June 2014 onwards