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Biology Grade 10 Unit 3: Biochemical Molecules

national exam questions have come from this unit. It runs 31 pages; one careful study pass takes about 3.6 hours, and its difficulty is easier among Biology units. Each section below lists the questions set from it, with the year, and opens the page that teaches it.

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3.1 Biochemical Molecules · read p. 51

Not asked in a national paper yet.

3.1.1 Inorganic molecule: Water · read p. 51

2018 E.C., Q78 – What is the main reason lipids are insoluble in water?
2016 E.C., Q14 – Which one of the following properties permits insects to freely walk on water? Its high
2015 E.C., Q75 – Which one of the following sentences correctly describes the properties of water? It
2013 E.C., Q57 – Which one of the following statements explains the property of water? It
2013 E.C., Q59 – Which property of water is useful for life that it continues in relatively warm water underneath through the cold weather?
2010 E.C., Q41 – Which is the possible effect of the weak hydrogen bond among water molecules?
2010 E.C., Q18 – Which of the following properties of water makes sweat a good body coolant?
2007 E.C., Q68 – Which of the properties of water allows mosquito larvae to hung themselves dawn in to the water from the water surface?

3.1.2 Inorganic ions · read p. 54

2017 E.C., Q16 – If your body cannot make enough red blood cells, which one of the following mineral rich foods can correct this problem?

3.1.3 Organic molecules · read p. 59

2018 E.C., Q75 – Which of the following is a polysaccharide that is a storage form of glucose in animals?
2018 E.C., Q79 – Which type of lipid is an ester of fatty acids and long-chain alcohols?
2018 E.C., Q73 – Which of the following is an example of a disaccharide?
2018 E.C., Q76 – What type of reaction results in the formation of disaccharides from monosaccharides?
2018 E.C., Q77 – Which of the following lipids are made up of fatty acids, glycerol or other alcohol, and phosphoric acid?
2018 E.C., Q1 – Which of the following is a major carbohydrate found in plants that humans cannot digest?
2018 E.C., Q80 – What is the primary function of glycolipids in the cell membrane?
2018 E.C., Q2 – Which of the following best describes the difference between saturated and unsaturated fatty acids?
2018 E.C., Q39 – What is the main difference between the structure of DNA and RNA?
2018 E.C., Q74 – What is the main difference between alpha-D-glucose and beta-D-glucose?
2017 E.C., Q34 – Which structural and functional difference is observed between DNA and RNA?
2017 E.C., Q9 – In an experiment, students wanted to prove that enzymatic digestion begins in the mouth using certain chewed food coated with their own saliva. In order to get a positive result for their experiment, what type of food sa
2016 E.C., Q81 – Which one of the following organic molecules has ester bonds in its molecular structure?
2016 E.C., Q85 – A student conducted a food test on three unknown food samples and obtained results as presented in the table below. No Procedures used Colour changes of the food samples after the experiment Food sample 1 Food sample 2 F
2016 E.C., Q44 – Which one of the following statements properly describes the structure of ATP? It is made up of
2015 E.C., Q77 – In animal cells, glycogen is hydrolyzed quickly to release glucose for respiration. This is due to the presence of several
2015 E.C., Q40 – This item is based on the following diagram which depicts structural formula of a biological molecule.
2015 E.C., Q92 – This item is based on the table below which shows a list of molecules. No Molecules 1 Calcium carbonate, glucose and methane 2 Carbon dioxide, linoleic acid and water 3 Linoleic acid, glucose and methane 4 Iron III oxide
2015 E.C., Q66 – Which one of the following is correct about DNA? It is
2014 E.C., Q41 – When three fatty acid molecules and a glycerol molecule undergo condensation reaction, they form
2014 E.C., Q87 – Which one of the following is correct with respect to the structural components of the plasma membrane?
2014 E.C., Q43 – Four students wanted to conduct chemical tests on unknown food particles and used the following chemicals and materials. Student A: Test tubes and burnet solution Student B: Test tubes, ethanol, water, filter paper Stude
2014 E.C., Q42 – In water, phospholipids become organized into a bilayer. In this configuration, which part of the bilayer faces towards the water?
2013 E.C., Q50 – Which one of the following is the correct formula of maltose?
2013 E.C., Q61 – Cellulose is
2013 E.C., Q62 – Which organic molecules are formed when two fatty acid molecules are bounded to the glycerol and the place of the third is taken by a phosphate group?
2013 E.C., Q88 – A biologist conducted simple experiment to investigate the effect of pH on salivary amylase. She added 5 cm3 amylase solution into starch suspension with a neutral pH in a test tube. After ten minutes, she tested it with
2013 E.C., Q60 – Consider the following table which contains organic and inorganic molecules. Which rows contain the corresponding organic and inorganic molecules correctly? No Organic Molecules Inorganic Molecules 1 Lysine, surcose Salt
2013 E.C., Q49 – Which one of the following organic molecules is used to make haemoglobin?
2013 E.C., Q70 – Which of the following is correct about the structure of the cell membrane?
2013 E.C., Q51 – A grade 11 student added Benedict's reagent on food sample and heated the mixture for 5 minutes. Then he observed a color change. Which one of the following is FALSE about the result?
2013 E.C., Q52 – In a Benedict's test for sucrose, why does the test sample first boil with hydrochloric acid?
2013 E.C., Q63 – All are the function of lipids EXCEPT
2012 E.C., Q16 – What is the role of cholesterol in the cell membrane?
2011 E.C., Q85 – Lipids to become sphingolipids must contain:
2011 E.C., Q13 – What are the compounds that have the same chemical composition, but different arrangement of atoms?
2011 E.C., Q35 – One of the following is a non-carbohydrate molecule.
2011 E.C., Q34 – Which of these elements is known to have less than 10% occurrence in many cells?
2011 E.C., Q22 – Of the following four elements, which one is the least abundant in living things?
2010 E.C., Q19 – How many molecule of glycerol and fatty acids, respectively, are needed to from 100 molecules of triglyceride fat?
2010 E.C., Q30 – In which industrial enzyme technology is lactase practical applied to produce lactose-free mile for used by lactose intolerant individuals?
2010 E.C., Q6 – Of the following organic molecules which one includes a pentose sugar?
2010 E.C., Q72 – Which of the following two elements are found in all organic molecules?
2010 E.C., Q29 – How are organic molecules distinguished from inorganic molecules? Organic molecules always contain:
2010 E.C., Q55 – To which group of sugar can the molecule dihydroxyacetone be classified ?
2010 E.C., Q80 – Which of the following organic molecules is least informative about the evolutionary relationships between species
2010 E.C., Q73 – If two molecule of a six carbon sugar are condensed to form a disaccharide, which of the following is the correct molecular formula of the disaccharide?
2010 E.C., Q70 – Which of the following nucleotide sequences contains four pyrimidine bases?
2009 E.C., Q24 – Among the following organic molecules, identify the one that dose not contain nitrogen.
2009 E.C., Q13 – Which one of the following is different from the other three?
2009 E.C., Q17 – Which type of fatty acids is healthier when used as a human food source?
2009 E.C., Q68 – Which of the following nitrogenous bases of nucleic acids is a purine base?
2009 E.C., Q21 – Which drop of iodine solution is added to a solution of a foodstuff and the foodstuff turns dark blue what dose the foodstuff contain
2009 E.C., Q11 – Which of the following bases is NOT found in RNA?
2009 E.C., Q62 – which of the following alternatives contain ONLY organic molecule?
2008 E.C., Q70 – Which of the following classes of fatty acids is without carbon-carbon double bond?
2008 E.C., Q73 – If it is known that the total amount of DNA in a cell is 300 units and that adenine contributes 70 of these units, how many units go to cytosine?
2008 E.C., Q52 – According to the fluid-mosaic model of the plasma membrane, what does the word 'mosaic' refer to?
2008 E.C., Q87 – Why does sucrose give a negative result when mixed and heated with Benedict's solution?
2008 E.C., Q9 – How many fatty acids would a cell need to form a molecule of triglyceride
2008 E.C., Q54 – Which of the following organic compounds would release both nitrogen and sulphur to the ecosystem when decomposed?
2008 E.C., Q1 – Which of the following food types would most likely give a negative result upon addition of iodine solution?
2008 E.C., Q39 – Which of the following molecules can serve as a raw material for industries that produce glucose?
2007 E.C., Q4 – To which one of the following organic molecules do enzymes belong?
2007 E.C., Q47 – What is the base found in RNA in place of thymine of DNA ?
2007 E.C., Q20 – If certain food stuff gave a positive result with benedicts test only after it was hydrolysed with hydrochloric acid, which of the following substances could it be?
2007 E.C., Q67 – Which of the following is true about all proteins?
2007 E.C., Q44 – Which element is found in nucleic acids?
2007 E.C., Q84 – Which of the following is a functional group of a fatty acid?
2007 E.C., Q56 – To which group of organic compounds do the triglycerides and waxes belong?
2007 E.C., Q82 – Which two nitrogenous bases belong to the purines?
2007 E.C., Q24 – Which of the following classes of molecule CANNOT pass easily across the cell membrane by simple diffusion?
2007 E.C., Q13 – A carbohydrate compound is known to have 12 carbon atoms in the whole molecule. What could this compound be?
2007 E.C., Q51 – In the formation of a macromolecule, what type of reaction would join two subunits together?
2007 E.C., Q52 – Which are the four most abundant elements in living cells?
2007 E.C., Q12 – What is the molecule that supplies the quickest and suitable source of energy to cells?
2007 E.C., Q32 – Which one of the following classes of organic molecule is the least important source of energy for cellular respiration?
2006 E.C., Q9 – Which molecule in the cell is the constituent of the gene?
2006 E.C., Q85 – If DNA contain 10% thymine, what is the percentage of cytosine in the DNA?
2006 E.C., Q26 – Which of the following carbohydrate has structural function?
2006 E.C., Q18 – Which of the following is a distinguishing feature of amino acids that is NOT found in carbohydrates?
2006 E.C., Q81 – Choose the one that represent a chemical formula of an organic compound?
2006 E.C., Q20 – Which one of the following molecule in living things is not an organic molecule?
2006 E.C., Q88 – Which of the following is produced when a lipid molecule is hydrolyzed?
2006 E.C., Q69 – Among the following identify the organelle in which nucleic acid is NOT found ?
2006 E.C., Q58 – Which of the following is true about the substance represented by the chemical formula ?
2006 E.C., Q51 – Which of the following is true about saturated fatty acids?
2006 E.C., Q14 – How many carbon and oxygen tomes are there in a molecule of maltose?
2006 E.C., Q41 – Which group of organic compound includes the enzymes?
2006 E.C., Q43 – Choose the characteristics that viruses share with living things.
2006 E.C., Q77 – How are unsaturated fats distinguished?
2006 E.C., Q1 – Which of the following do viruses share with cells?
2005 E.C., Q53 – Most cell membrane are primarily composed of which compounds
2005 E.C., Q4 – The main components of the plant cell wall are ____________?
2005 E.C., Q14 – Which energy rich organic compound contains adenine in its molecule ?
2005 E.C., Q87 – Which of the following groups of substance are all inorganic?
2005 E.C., Q80 – Which of the following is generally expected to give better health benefits when presence in human diet?
2005 E.C., Q10 – All proteins contain carbon, hydrogen, oxygen and what other element?
2005 E.C., Q47 – What is the name of the suger found in milk?
2005 E.C., Q12 – How many carbon atoms are there in one disaccharide molecule?
2005 E.C., Q22 – Which of the following pairs of molecule are known to have catalytic activity?
2005 E.C., Q71 – What can one conclude about the contents of the food stuff if a mixture of Benedict solution and foodstuff remain blue after heating ?
2005 E.C., Q1 – Which one of the following is the main constituent of biological membranes?
2005 E.C., Q79 – In which of the following compound are both members of the pair are polymers of carbohydrates that naturally occur in plants only?
2005 E.C., Q69 – In which of its contents RNA differs from DNA?
2005 E.C., Q26 – When two species are compared ,which of the following sources of evidence is least informative about the degree of relationships between the species?
2005 E.C., Q21 – What makes unsaturated fatty acids different from saturated fatty acids?
2005 E.C., Q49 – Which of the following crops is considered to be the best choice for a better balance of essential amino aides as a human diet?