Practice Biology questions for Induction day test 206 Q. The drawing shows an animal cell, seen at a very high magnification using an electron microscope. (a) (i) Label a mitochondrion [plural = mitochondria]. () What happens in the mitochondria?.. () (b) (i) Name and label the structure where you would find chromosomes. () What are chromosomes made of?.. () (c) What controls the rate of chemical reactions in the cytoplasm?... () (Total 5 marks) Page
Q2.A student uses a microscope to look at a section through part of a leaf. The diagram shows the student s drawing. (a) (i) Name tissues A and B. A B (2) The part of the leaf labelled C contains two different tissues that transport substances to and from the leaf. Name the two tissues found in part C. 2 (2) (b) The lower leaf surface has thousands of pores. The pores in the leaf surface allow the diffusion of gases between tissue B and the atmosphere. When the leaf is photosynthesising quickly the diffusion of gases through the pores is much faster than when the leaf is photosynthesising slowly. Explain why. Page 2
(2) (Total 6 marks) Q3. (a) Complete the equation for photosynthesis. lightenergy... +...... + oxygen (2) (b) Scientists investigated how temperature affects the rate of photosynthesis. The scientists grew some orange trees in a greenhouse. They used discs cut from the leaves of the young orange trees. The scientists used the rate of oxygen production by the leaf discs to show the rate of photosynthesis. (i) The leaf discs did not produce any oxygen in the dark. Why? () The leaf discs took in oxygen in the dark. Explain why. (2) Page 3
(c) In their investigation, the scientists measured the rate of oxygen release by the leaf discs in the light. The scientists then measured the rate of oxygen uptake by the leaf discs in the dark. The graph shows the effect of temperature on oxygen production in the light oxygen production in the light added to oxygen uptake in the dark. Use the information from the graph to answer each of the following questions. (i) Describe the effect of temperature on oxygen production in the light. (2) Page 4
Explain the effect of temperature on oxygen production in the light when the temperature is increased: from 25 C to 35 C from 40 C to 50 C. (2) (d) A farmer in the UK wants to grow orange trees in a greenhouse. He wants to sell the oranges he produces at a local market. He decides to heat the greenhouse to 35 C. Explain why he should not heat the greenhouse to a temperature higher than 35 C. Use information from the graph in your answer. (3) (Total 2 marks) Q4. Fresh milk is a mixture of compounds including fat, protein and about 5 % lactose sugar. Lactose must be digested by the enzyme lactase, before the products can be absorbed. Lactase can be added to fresh milk to pre-digest the lactose. This makes lactose-free milk, which is suitable for people who do not produce enough lactase of their own. A student investigated the effect of changing ph and temperature on the digestion of lactose in milk. Page 5
The results are shown in Tables and 2. Table Effect of ph Table 2 Effect of temperature ph Time taken to digest lactose in minutes Temperature in C Time taken to digest lactose in minutes 4.0 20 30 20 5.0 8 35 4 6.0 3 40 7.0 7 45 6 8.0 5 50 2 9.0 6 55 23 (a) The label on a carton of lactose-free milk states: Lactase is normally produced in the stomach of mammals. The results in Table show that this statement is unlikely to be true. Explain how. (2) (b) Explain as fully as you can the results shown in Table 2. Page 6 (3)
(c) Bile is produced in the liver and is released into the small intestine. Explain how bile helps the digestion of milk. (2) (Total 7 marks) Q5. (a) Respiration is a process which takes place in living cells. What is the purpose of respiration?...... () (b) (i) Balance the equation for the process of respiration when oxygen is available. C6H2O6 + O2 CO2 + H2O () What is the name of the substance in the equation with the formula C6H2O6?.. () (c) Oxygen is absorbed through the alveoli in the lungs. (i) How are the alveoli adapted for this function?...... Name the gas which is excreted through the alveoli... (2) () Page 7
(d) (i) What is the name of the process of respiration when oxygen is not available?.. () Describe the process of respiration which takes place in human beings when oxygen is not available and give an effect............. (3) (Total 0 marks) Q6.Some molecules can move into and out of cells across the cell membrane. (a) Dissolved substances move into and out of cells. Name this process. () (b) Diagram shows a model of a cell surrounded by water. The model cell contains a solution of two molecules, A and B. In the diagram, the circles represent molecules of A and B. The cell membrane contains small holes that allow molecules to pass through. Page 8
Diagram (i) Describe what will happen to the number of molecules of A and of B in the cell and in the water, in the next few hours. (3) Explain the reasons for your answer to part (b)(i). (2) Page 9
(c) Oxygen can pass through membranes into cells. Oxygen passes from the lungs into the blood. Diagram 2 shows a blood vessel and cells at the surface of the lung. Diagram 2 (i) Why do cells need oxygen? () Blood moves along the blood vessel all the time. In terms of oxygen passing into the blood from the lungs, why is the movement of blood important? (2) (Total 9 marks) Q7. The drawing shows a white blood cell ingesting a bacterium. Label the parts of the white blood cell. (Total 3 marks) Page 0
Q8.Phenylketonuria (PKU) is an inherited condition. PKU makes people ill. (a) PKU is caused by a recessive allele. (i) What is an allele? What is meant by recessive? () () (b) The diagram below shows the inheritance of PKU in one family. (i) Give one piece of evidence from the diagram that PKU is caused by a recessive allele. () Persons 6 and 7 are planning to have another child. Use a genetic diagram to find the probability that the new child will have PKU. Use the following symbols in your answer: N = the dominant allele for not having PKU n = the recessive allele for PKU. Probability =... (4) Page
(c) Persons 6 and 7 wish to avoid having another child with PKU. A genetic counsellor advises that they could produce several embryos by IVF treatment. (i) During IVF treatment, each fertilised egg cell forms an embryo by cell division. Name this type of cell division. () An embryo screening technique could be used to find the genotype of each embryo. An unaffected embryo could then be placed in person 7 s uterus. The screening technique is carried out on a cell from an embryo after just three cell divisions of the fertilised egg. How many cells will there be in an embryo after the fertilised egg has divided three times? () (iii) During embryo screening, a technician tests the genetic material of the embryo to find out which alleles are present. The genetic material is made up of large molecules of a chemical substance. Name this chemical substance. () (d) Some people have ethical objections to embryo screening. (i) Give one ethical objection to embryo screening. () Give one reason in favour of embryo screening. () (Total 2 marks) Page 2
Q9. (a) How do fossils provide evidence that species alive today have evolved from simpler organisms? (3) (b) The photographs show two species of gull. Herring gull (Larus argentatus) Lesser black-backed gull (Larus fuscus) By Ken Billington (Own work) [CC-BY-SA-3.0],via Wikimedia Commons By Andreas Trepte (Own work) [CC-BY-SA-2.5],via Wikimedia Commons Both species are now found in the UK but the two species cannot interbreed with each other. Scientists believe that these two species have evolved from a common ancestor. Page 3
The map on the next page shows a view of the Earth from above the North Pole. The map also shows where these two species are found. Suggest an explanation for the development of these different species. (6) (Total 9 marks) Page 4
Markscheme M. (a) (i) award mark for any of the mitochondria correctly labelled if a number are labelled and one is incorrect award 0 marks respiration or the release or transfer of energy or it contains the enzymes for respiration do not accept energy produced (b) (i) nucleus (named and correctly labelled) arrow or line must touch or go inside the nuclear membrane DNA or genes or nucleic acids Page 5
accept protein or histones or nucleotides or ATGC (c) enzymes or nucleus do not accept factors that affect the rate rather than control it eg ph or temperature [5] M2.(a) (i) A = epidermis allow epidermal ignore upper B = mesophyll allow palisade and spongy mesophyll xylem either order phloem accept phonetic spellings (b) either oxygen produced faster allow more oxygen produced / released or Page 6
carbon dioxide used faster allow more carbon dioxide used / taken in / needed increases diffusion gradient allow increases difference in concentration (between inside and outside) allow more oxygen in the leaf compared to outside or less carbon dioxide in leaf compared to outside the leaf [6] M3. (a) LHS: carbon dioxide AND water in either order accept CO2 and H2O allow CO2 and H2O if names given ignore symbols do not accept CO 2 / H 2 O / Co / CO ignore balancing RHS: sugar(s) / glucose / starch / carbohydrate(s) accept C6H2O6 allow C6H2O6 do not accept C 6 H 2 O 6 (b) (i) light is needed for photosynthesis or no photosynthesis occurred (so no oxygen produced) oxygen is needed / used for (aerobic) respiration full statement respiration occurs or oxygen is needed for anaerobic respiration gains mark 2 (c) (i) (with increasing temperature) rise then fall in rate Page 7
use of figures, ie max. production at 40 C or maximum rate of 37.5 to 38 25 35 C either faster movement of particles / molecules / more collisions or particles have more energy / enzymes have more energy or temperature is a limiting factor over this range 40 50 C denaturation of proteins / enzymes ignore denaturation of cells ignore stomata (d) above 35 C (to 40 C) little increase in rate or > 40 C causes decrease in rate so waste of money or less profit / expensive because respiration rate is higher at > 35 C or respiration reduces the effect of photosynthesis [2] M4. (a) stomach is acidic / has low ph allow any ph below 7 ignore stomach is not alkaline Page 8
lactase works best / well in alkali / high ph / neutral / non-acidic conditions allow any ph of 7 and above accept works slowly in acid conditions allow figures from table with a comparison ignore reference to temperature (b) any three from (below 45( C)) increase in temperature increases rate / speed of reaction reference to molecules moving faster / colliding faster / harder / more collisions optimum / best at 45( C) allow value(s) in range 4-49 high temps / above 45( C) (rate slows due to) denaturation of enzyme /lactase allow synonyms of denaturation but not killed denaturation at high and low temperature does not gain this mark ignore body temperature ignore references to time / ph 3 (c) any two from acid neutralised or conditions made neutral / alkali accept bile is alkaline (allow) emulsification / greater surface area of fat / lipid allow description of emulsification eg fat is broken down / broken up into droplets enzymes (in small intestine) work (more effectively / better) allow better for enzymes 2 [7] M5. (a) to transfer / provide / give release energy or production of ATP / adenosine triphosphate (molecules) Page 9
accept to give heat (b) (i) C6H2O6 + 6O2 6CO2 + 6H2O accept any other n : 6n : 6n : 6n ratio do not credit if any other changes have been made glucose do not credit sugar / sucrose (c) (i) any two from large surface thin (surface) moist (surface) (with a good) blood supply carbon dioxide accept water vapour do not credit just water 2 (d) (i) anaerobic (respiration) any three from in mitochondria glucose decomposes / breaks down / reacts or glucose lactic acid for (2) marks to give lactic acid or breathing hard or lactic acid CO2 + water causing pain (leaving an) oxygen debt (quick) source of energy (but) less efficient than aerobic respiration accept less efficient than with oxygen Page 20 3 [0]
M6.(a) diffusion ignore absorption (b) (i) any three from max 2 marks for A or B only (the number of) A decreases in the cell (the number of) A increases in the water if neither of first two bullet points given allow mark for A moves out of cell / membrane or A moves into water until (number of) A is equal inside and outside cell or until (number of) A is half what it was at beginning (in cell) accept the idea that the concentrations of A in the cell and in the water will become (close to) equal (the number of) B stays the same in the cell there are no (molecules of) B in the water if neither bullet point 4 nor 5 is given allow mark for B does not move out of cell or B does not move into the water 3 (molecules of) A small enough to pass through holes / membrane allow membrane permeable to A or membrane not permeable to B or (molecules of) B too large to pass through holes / membrane allow reference to size of holes (in membrane) being too small for B or large enough for A, to pass through once concentration of molecules of A is the same inside and outside cell there will be no (net) movement Page 2
allow this idea in terms of numbers of molecules or A moves from high concentration (in cell) to low concentration (in water) (c) (i) for (aerobic) respiration ignore references to energy or uses of energy eg contraction or to respire do not accept anaerobic respiration any two from: removes oxygen that has diffused / passed into blood keeps difference (in concentration) between lungs and blood high accept idea of maintaining diffusion / concentration gradient increases speed of diffusion / passage of oxygen into blood if no other mark given allow mark for so oxygen can reach the cells / (named) parts of the body 2 [9] M7. cytoplasm reject protoplasm (cell) membrane nucleus all correctly labelled each for mark [3] M8.(a) (i) one form of a / one gene do not allow a type of gene allow a mutation of a gene Page 22
not expressed if dominant / other allele is present / if heterozygous or only expressed if dominant allele not present / or no other allele present allow need two copies to be expressed / not expressed if only one copy / only expressed if homozygous (b) (i) two parents without PKU produce a child with PKU / 6 and 7 0 allow it skips a generation genetic diagram including: accept alternative symbols if defined Parental gametes: 6: N and n and 7: N and n derivation of offspring genotypes: NN Nn Nn nn allow genotypes correctly derived from student s parental gametes identification: NN and Nn as non-pku OR nn as PKU allow correct identification of student s offspring genotypes correct probability only: 0.25 / ¼ / in 4 / 25% / : 3 do not allow 3 : / : 4 do not allow if extra incorrect probabilities given (c) (i) mitosis correct spelling only Page 23
8 (iii) DNA allow deoxyribonucleic acid do not allow RNA / ribonucleic acid (d) (i) may lead to damage to embryo / may destroy embryos / embryo cannot give consent allow avoid abortion allow emotive terms eg murder religious argument must be qualified allow ref to miscarriage allow idea of avoiding prejudice against disabled people allow idea of not producing designer babies any one from: prevent having child with the disorder / prevent future suffering / reduce incidence of the disease ignore ref to having a healthy child ignore ref to selection of gender embryo cells could be used in stem cell treatment allow ref to long term cost of treating a child (with a disorder) allow ref to time for parents to become prepared [2] M9. (a) fossil is (remains / impression of) organism that lived a long time ago if numbers, 000s years fossils show changes over time or older fossils simpler or fossils simpler than present-day species fossils have similar features to present-day species allow fossils allow us to compare old species with present-day species Page 24
(b) isolation / separation / splitting by geographical barrier / sea ignore other examples there was variation (in these isolated populations) / different alleles accept mutation different environmental conditions or example eg climate / predators / food natural selection acted on the isolated populations accept became adapted in each area OR only certain allele(s) passed on to offspring / different alleles passed on in different environments allow genes so differences lead to inability to interbreed allow differences described eg mismatch of genitalia / different courtship displays / different breeding seasons [9] Page 25