Q1. - QCL Science - Home



2E Animal & Plant NutritionTime: 1 hour 30 minutesTotal marks available: 90Total marks achieved: plex carbohydrates are broken down in the human digestive system.Name the elements present in a carbohydrate molecule...............................................................................................................................................Starch and glucose are carbohydrates found in living plete the table to show some of the properties of starch and glucose. Insert a tick if the property applies or a cross if it does not.(1)(5)(i) Describe how you could test for the presence of glucose in a substance.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(ii) Give two safety precautions you would take when carrying out the test.........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(3)(2)(Total for question = 11 marks)Q2.Read the passage below. Use the information in the passage and your own knowledge to answer the questions that follow.Suggest how spending time outdoors can reduce the chance of getting rickets (lines 7 and 8).(1)..........................................................................................................................................................................................................................................................................................................................................................................................................................................Suggest why vitamin D deficiency is more of a problem for children than for adults...........................................................................................................................................................................................................................................................................................................................................................................................................................................Vitamins are an essential part of a balanced diet. Give three other components of a balanced diet...........................................................................................................................................................................................................................................................................................................................................................................................................................................Suggest why snacking on crisps, chocolate and soft drinks is an unsuitable diet for children who are not very active (lines 16 and 17).......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Suggest the health problems that might develop if children have too much fat in their diet (line 18).....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(f ) Describe how you would carry out an experiment to find out the energy value of a potato crisp...........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(1)(3)(2)(2)(4)..............................................................................................................................................(Total for question = 13 marks)Q3.The Bristol scale is used to classify human faeces. It is used to help diagnose patients who have problems with their alimentary canal.Suggest why a patient might produce Type 1 faeces...........................................................................................................................................................................................................................................................................................................................................................................................................................................Suggest why a patient might produce Type 7 faeces...........................................................................................................................................................................................................................................................................................................................................................................................................................................Describe how food is moved through the gut...............................................................................................................................................(1)(1)(3)......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Name the part of the gut where faeces arestored..............................................................................................................................................expelled..............................................................................................................................................Explain how egestion differs from excretion...........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(1)(1)(3)(Total for question = 10 marks)Q4.511809429461The table shows the percentage of protein, fat and minerals found in the same mass of meat from different animals.(i) Which meat contains the least protein?..............................................................................................................................................(ii) Calculate how many grams of protein are present in one kilogram of rabbit meat. Show your working.(1)(2)Answer ........................................................... gWhich type of meat would provide the most energy?..............................................................................................................................................Give two uses of fat in the human body.............................................................................................................................................................................................................................................................................................Name the mineral in meat that is needed to make haemoglobin...............................................................................................................................................(1)(2)(1)(Total for question = 7 marks)Q5.1493519254201The photograph shows a water plant growing on the surface of a lake.This water plant grows by increasing the number of its leaves. Many mineral ions help plants to grow.Describe how one named mineral ion helps plants to grow.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Copper ions inhibit the growth of this water plant.To investigate this effect, a student put four plants with a total of 10 leaves into a beaker containing 400 cm3 of mineral ion solution together with a copper coin.She repeated this with 400 cm3 of the mineral ion solution without a copper coin. She counted the number of living leaves each day for the next eight days.The table shows her results.(2)Plot a line graph on the grid below to show the results of her investigation. Use a ruler to join the points with straight lines.(6)1497964152792In this investigation, the concentrations and volumes of the mineral ion solution and the species of water plant were kept the same.Name three other variables that need to be kept the same for the results ofthis investigation to be valid.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(3)(Total for question = 11 marks)Q6.During photosynthesis, plants absorb carbon dioxide through their leaves.Describe how the structure of a leaf is adapted to absorb carbon dioxide.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Write the balanced chemical equation for photosynthesis...............................................................................................................................................A simple controlled experiment can be carried out to show that a plant leaf produces starch when exposed to light.At the start of the experiment, all of the starch should be removed from the leaf. Suggest how this could be done...........................................................................................................................................................................................................................................................................................................................................................................................................................................Describe the control you would set up in this experiment...........................................................................................................................................................................................................................................................................................................................................................................................................................................Describe how you would test a leaf for starch.Include the safety precautions you would take and the results you would expect to see.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(3)(2)(1)(1)(3)(Total for question = 10 marks)Q7.The photograph shows a variegated leaf. The dark (green) part of the leaf has cells that contain chloroplasts. The white part of the leaf has cells that do not contain chloroplasts.Describe the role of chloroplasts in leaf cells.........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................The diagram shows a leaf cell from the green part of the leaf.Name the parts labelled A, B and C.(2)(3)A ..................................................................................................................................................................................................B ..................................................................................................................................................................................................C ..................................................................................................................................................................................................The diagram shows a plant with variegated leaves.The plant was destarched by leaving it in the dark for 24 hours.Leaf X then had a strip of black paper attached to both the upper and lower surfaces. It was then sealed in a flask containing a solution of sodium hydroxide, a substance that absorbs carbon dioxide.Leaf Y also had a strip of black paper attached to both the upper and lower surfaces.The plant was then placed in the light for 24 hours and then a starch test was carried out on leaf X and leaf Y.The five leaves, A to E, show the possible appearance of leaf X and leaf Y after the starch test.Which of the leaves A to E matches the result you would obtain after testing leaf X and leaf Y for starch?(2)leaf X ............................................................................................................................................................................................leaf Y ............................................................................................................................................................................................Explain what happens in a leaf when it is destarched.........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)Describe how the green pigment in leaf cells is removed safely before testing a leaf for the presence of starch...............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Name the chemical used to test for starch...............................................................................................................................................(3)(1)(Total for question = 13 marks)Q8.1222375254201The diagram shows a section through a leaf.Name the structures labelled A and B.(2)A ....................................................................................................................................................................................................B ....................................................................................................................................................................................................Give the function of the waxy cuticle.............................................................................................................................................................................................................................................................................................Some of the leaf cells carry out photosynthesis. Write a word equation for this process...............................................................................................................................................Plants, like all living organisms, need to excrete waste products. Explain how the excretory product of photosynthesis is removed from the leaf...........................................................................................................................................................................................................................................................................................................................................................................................................................................Some plants lose their leaves in cooler months. This can be described as an excretory mechanism. Suggest two other reasons why some plants lose their leaves in cooler months.(1)(2)(2)(2)1 ...................................................................................................................................................................................................................................................................................................................................................2 ...................................................................................................................................................................................................................................................................................................................................................Name one excretory organ in humans and name the substance it an..............................................................................................................................................substance..............................................................................................................................................(2)(Total for question = 11 marks)Q9.1851660429461The diagram shows the label on a packet of a new kind of food for people who want to lose weight.The food is a powder which is added to water to make a liquid drink. The label on the packet claims that the food provides a complete balanced diet.What is meant by the term balanced diet?........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................A pregnant woman decides that this food does not provide her with a complete balanced diet.Use the information on the packet to give two reasons why the pregnant woman may be right.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(2)(2)(Total for question = 4 marks)Q1.This question was on carbohydrates. All but a very few candidates could give the elements present in a carbohydrate molecule in part a). However, only the best candidates gained full credit in part b) for completing the table on the properties of starch and glucose. In part c) most candidates were able to describe a test they could carry out for glucose. A number of responses included adding glucose to the substance to be tested. Most responses also gave two safety precautions such as heating in a water bath and wearing safety glasses.Q2.The comprehension was about diet in children and tested understanding of vitamins, balanced diet and energy balance. In part (a), most appreciated that spending time outdoors allows sunlight to make vitamin D and so reduce the chance of getting rickets. Those who thought sunlight contains vitamin D were not credited. Part (b) was more challenging, but about 60% appreciated that children are still growing which is why a vitamin D deficiency would cause a problem, particularly with bone development. Those who did not read the question carefully wrote about the time children spend indoors or commented on the amount of cod liver oil they take. Most candidates were able to list three other components of a balanced diet in part (c). In part (d), a pleasing number of candidates appreciated the energy balance implications of eating foods rich in carbohydrates and fats and not using the calories due to hypoactivity. Then, in part (e), many were aware of the health risks of a high fat diet in causing obesity, cardiovascular disease and diabetes. Part (f) required candidates to write about a practical procedure listed in the specification. Those who had carried out the practical were able to recall many of the points allowed in the mark scheme. However, it was clear that some candidates had no idea what was required to find out the energy value of a food sample.Q3.This question provided students with a copy of the Bristol scale used to diagnose problems with alimentary canal function. In parts (a) and (b) the more able candidates were able to suggest why the different form of faeces might be produced. In part (c) the question required candidates to describe how food is moved through the gut. Most responses gained some marks with the best responses describing peristalsis as contraction of the circular and longitudinal muscles in the gut wall. In (d) most candidates could name the part where faeces are expelled but fewer could name the part where faeces are stored. In part (e) candidates needed to explain how egestion differs from excretion. Very few seemed to understand the differences and only the best candidates scored full marks. Many responses talked about faeces being excreted and few candidates knew what egestion was.Q4.This question presented data on the protein, fat and mineral content of 5 different meats. In part a) almost every candidate could correctly identify the meat with least protein and calculate how many grams would be present in one kilogram of rabbit meat.Q5.The question gave a picture of a water plant growing on a lake. In (a), most candidates were able to suggest a mineral ion required by a plant and its role inthe plant. We would expect candidates to give the ions required in the specification - magnesium for chlorophyll or nitrate for amino acids. However, other ions were also credited. Candidates then had to plot a line graph of some experimental results in (b). Those from centres who had practiced graph plotting scored very well. In (d), many candidates could identify three variables to be kept constant with light intensity, carbon dioxide level and temperature being the most common correct answers.Q6.required a description of how the leaf is adapted to absorbcarbon dioxide. Many candidates gained full credit for writing about the presence of a large surfaces area and many stomata. The thinness of the leaf provides a short diffusion distance and the moist surfaces of the spongy mesophyll cells. Incandidates had to write a balanced chemical equation for photosynthesis. Although many gained full marks some confused respiration, others gave wrong formulae. In part (c) students needed to remember the practical experiment used to show that light is required for photosynthesis. This is straight from the specification and we were disappointed by how many candidates did not know how to destarch a leaf or test one for starch.Q7.This question gave candidates a photograph of a variegated leaf. In (a) almost all could describe the role of chloroplasts. Again, In part (b), most couldname the structures in the diagram of the plant cell. The experiment described in part (c) should have been familiar to all candidates. However this item (iv) discriminated well between candidates and only the best could identify the appearance of the leaves after testing for starch. In parts (ii) and (iii) those candidates who had carried out investigations testing leaves for starch could answer well and those who had not seen this practical performed poorly. In part (iv) almost all could correctly identify iodine solution as the chemical test for starch.Q8.This question provided a diagram of a section through a leaf. In part a) almost all candidates could correctly name the structures labelled. Most were able to give the function of the waxy cuticle as reducing transpiration and preventing entry of microorganisms. Most could also give the word equation for photosynthesis, although a significant minority chose to give chemical formulae. In the final part the better candidates gained full credit for explaining that oxygen exits the stomata down a diffusion gradient from a high concentration to a lower one outside the leaf. Part b) asked candidates to suggest reasons why some plants lose their leaves in cooler months. Answers that gained credit included reduction of water loss, lack of sunlight for photosynthesis and conservation of energy resources.Q9.This question required students to use information from a label on a slimming drink. In part (a) most students gained some credit with the best answers describing a balanced diet as containing the correct proportions of carbohydrate, protein, lipid, vitamins and minerals. In part (b) most could identify why the drink would not be suitable for a pregnant woman.Q1.507365136310Q2.Question numberAnswerNotesMarks(a)sun/ light makes vitamin D;1(b)children still growing (bones) Ideveloping(bones) / eq;allow converse -adult bones fully developed ignore ref to cod liver oil / timespent indoors1(c)fat / lipid;carb ohydrate; protein;fibre I roughage;water;minerals / salts / ions;only accept generic names, so iron = O, glucose = Oif list ignore non gene ric namesMax 3(d)1 , idea of high in sugar / fat /carbohydrateI energy I calories2. not used / not burnt / not neededI eq;marks are for idea of energy balanceand not consequence2{e)1 , obesity / overweight / jointdamage;diabetes;heart disease I heart attack / angina Icardiac arrest / eq;blocks/ narro ws/ build up arteriesignore vein / capillaryMax 2Iblocks blood vessels / high bloodpressure;5. stroke;{f)1 , weigh crisp / mass of crisp;burn crisp / eq;burnt completely I eq;heat water /hold ! burning crisp) under tube / hold burning crisp) under water / calorimeter / eq;volumeof water / mass of water;measure temperature before and after Itemperature rise I temperature increase Ichange in temperature / eq;allow marks ifclear in formulaallow heat water if implicitMax 4Tota l 13 marksQ3.507365136310Q4.Q5.507365107088Q6.Q7.507365136310Q8.Q9.507365136310 ................
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