B Cell Biology 35 Questions Name: Class: Date: Time: Marks: Comments: Page of 88
Figure shows an animal cell. Figure (a) What is structure A? Tick one box. alex-mit/istock/thinkstock Cell membrane Cell wall Chromosome Cytoplasm () Page 2 of 88
(b) What is structure B? Tick one box. Chloroplast Mitochondria Nucleus Vacuole () (c) Figure 2 shows a sperm cell. Figure 2 Describe how a sperm cell is adapted to carry out its function. () Page 3 of 88
(d) Substances can move into and out of cells by three processes. The diagrams show the concentration of different substances inside and outside a root hair cell. How would each substance move into the root hair cell? Draw one line from each root hair cell to the correct process. Root hair cell Process (2) (Total 5 marks) Page 4 of 88
2 The figure below shows a scale drawing of one type of cell in blood. (a) Use the scale to determine the width of the cell. Give your answer to the nearest micrometre. Width of cell = micrometres () (b) Complete the table below. Part of the blood Function Carries oxygen around the body Protects the body against infection Plasma (3) Page 5 of 88
(c) Platelets are fragments of cells. Platelets help the blood to clot. Suggest what might happen if the blood did not clot. () (Total 5 marks) 3 When an organism grows, new cells are produced by cell division. (a) What type of cell division happens to produce new body cells? Tick one box. Differentiation Meiosis Mitosis () (b) Why can cancers grow very large? Tick one box. Cancer cells are specialised Cell division is slow Cell division is uncontrolled () (c) Give one factor which increases the risk of getting cancer. () Page 6 of 88
(d) Survival rates for people with cancer have improved a lot. People who are alive 0 years after diagnosis are usually considered to be cured. The figure below shows data for people diagnosed with cancer in 96 and 200. 78% of people diagnosed with breast cancer in 200 were alive 0 years later. Complete the figure above to show this information. () (e) Which type of cancer diagnosed in 96 had the highest survival rate? Tick one box. Breast Prostate Skin Testicular () Page 7 of 88
(f) Which type of cancer shows the biggest improvement in the percentage of people alive after 0 years? Tick one box. Breast Prostate Skin Testicular () (g) Suggest two reasons why the survival rates for all cancers have increased.. 2. (2) (Total 8 marks) Page 8 of 88
4 Pathogens cause infectious diseases in animals and plants. (a) Draw one line from each disease to the type of pathogen that causes the disease. Disease Type of pathogen Bacterium Gonorrhoea Fungus Malaria Protist Measles Virus (3) Page 9 of 88
(b) Some parts of the human body have adaptations to reduce the entry of live pathogens. Look at Figure. Figure Explain how the trachea is adapted to reduce the entry of live pathogens. (4) Page 0 of 88
(c) Malaria is a serious disease that can be fatal. Malaria is spread to humans by infected mosquitoes. Scientists investigated the behaviour of mosquitoes to understand how the spread of malaria could be controlled. Figure 2 shows the equipment the scientists used. Figure 2 This is the method used.. 30 mosquitoes infected with malaria were placed in Container A. 2. 30 uninfected mosquitoes were placed in Container B. 3. The total number of times the mosquitoes landed on the socks was recorded. Name the dependent variable and suggest one control variable in this investigation. Dependent variable Control variable (2) Page of 88
(d) Infected mosquitoes landed on the socks three times more often than uninfected mosquitoes. Explain how this information can be used to reduce the spread of malaria. (2) Page 2 of 88
(e) Tobacco mosaic virus (TMV) affects many species of plant. Figure 3 shows a leaf infected with TMV. Figure 3 Nigel Cattlin/Getty Images TMV destroys chloroplasts in the leaf. Explain how this could affect the growth of the plant. (3) (Total 4 marks) Page 3 of 88
5 The figure below shows four different types of cell. (a) Which cell is a plant cell? Give one reason for your answer. Cell Reason (2) (b) Which cell is an animal cell? Give one reason for your answer. Cell Reason (2) (c) Which cell is a prokaryotic cell? Give one reason for your answer. Cell Reason (2) Page 4 of 88
(d) A scientist observed a cell using an electron microscope. The size of the image was 25 mm. The magnification was 00 000 Calculate the real size of the cell. Use the equation: Give your answer in micrometres. Real size = micrometres (3) (Total 9 marks) 6 Plants need nitrate ions in order to make proteins. A plant is growing in soil flooded with water. Explain why the plant cannot absorb enough nitrate ions. (Total 5 marks) Page 5 of 88
7 (a) Some antibiotics work by destroying the cell membranes of bacteria. Suggest why these antibiotics may have side effects in the animals that are given these antibiotics. () (b) Each arrow on the figure below shows the date of discovery of each new type of antibiotic. In which 0 year period were most new types of antibiotic discovered? () (c) The figure above shows 22 new types of antibiotic. These were discovered before 200. Determine the percentage of types of antibiotic that have been discovered between 980 and 200. Use information from the figure above. Give your answer to 2 significant figures. % (2) Page 6 of 88
(d) Bacteria can evolve rapidly. Many bacteria can develop into new strains which are resistant to antibiotics. Complete the table below to show if each action is more likely or less likely to help bacteria to become antibiotic resistant. Put a tick in each row. Action More likely Less likely Take painkillers for headache Washing with antiseptic hand gel Adding antibiotics to food for cows Giving antibiotics for colds and flu Stopping antibiotics as soon as you feel better (4) (Total 8 marks) Page 7 of 88
8 Starfish can split in half. Each half can then grow new arms to form offspring. This process is shown in the figure below. (a) What process produces the starfish offspring? Tick one box. Asexual reproduction Fertilisation Selective breeding Sexual reproduction () (b) More cells are produced as the starfish grows more arms. What process will produce more cells in the starfish as they grow? () (c) All the offspring produced are genetically identical. What name is given to genetically identical organisms? () Page 8 of 88
(d) Each body cell of the parent starfish contains 44 chromosomes. How many chromosomes are in each body cell of the offspring? () (Total 4 marks) 9 Students used quadrats to estimate the population of dandelion plants on a field. (a) Describe how quadrats should be used to estimate the number of dandelion plants in a field. (4) (b) The field measured 40 m by 45 m. The students used 0.25 m 2 quadrats. The students found a mean of 0.42 dandelions per quadrat. Estimate the population of dandelions on the field. Estimated population of dandelions = (2) Page 9 of 88
(c) In one area of the field there is a lot of grass growing in the same area as dandelions. Suggest why the dandelions may not grow well in this area. (4) (Total 0 marks) 0 Different antibiotics destroy bacteria in different ways. Some antibiotics disrupt the bacterial cell membrane. Some antibiotics disrupt the bacterial cell wall. (a) Antibiotics that disrupt the bacterial cell membrane often cause more side effects in humans compared with antibiotics that disrupt bacterial cell walls. Suggest why. () (b) Some antibiotics prevent ribosomes functioning. Suggest how this damages the bacterium. () Page 20 of 88
(c) Drug manufacturers are spending less on research into new antibiotics. One reason why is because new antibiotics are rarely prescribed. Some people think that governments should pay drug manufacturers to develop new antibiotics. Suggest why. (3) (Total 5 marks) Figure shows a cell viewed through a light microscope. Figure The size of the real cell is 0.03 mm. (a) Calculate the magnification of the microscope. Use Figure to help you answer. Magnification = (2) Page 2 of 88
(b) A light microscope uses light waves to observe objects. Light waves can be modelled using water waves. Figure 2 shows a water wave. Figure 2 Give one similarity between a light wave and a water wave. () (c) Write down the equation that links frequency, wave speed and wavelength. () (d) The wave in Figure 2 has a wavelength of 75 cm. The wave moves at a speed of.6 m / s. Calculate the frequency of the wave. Frequency = Hz (4) (Total 8 marks) Page 22 of 88
2 (a) In humans there are two types of cell division: mitosis and meiosis. The table below gives statements about cell division. Tick ( ) one box in each row to show if the statement is true for mitosis only, for meiosis only, or for both mitosis and meiosis. The first row has been done for you. Statement Mitosis only Meiosis only Both mitosis and meiosis How cells are replaced How gametes are made How a fertilised egg undergoes cell division How copies of the genetic information are made How genetically identical cells are produced (4) (b) Stem cells can be taken from human embryos. In therapeutic cloning, an embryo is produced that has the same genes as the patient. (i) Name one source of human stem cells, other than human embryos. () Stem cells from embryos can be transplanted into patients for medical treatment. Give one advantage of using stem cells from embryos, compared with cells from the source you named in part (i). () (Total 6 marks) Page 23 of 88
3 The image below shows an epithelial cell from the lining of the small intestine. (a) (i) In the image above, the part of the cell labelled A contains chromosomes. What is the name of part A? () How are most soluble food molecules absorbed into the epithelial cells of the small intestine? Draw a ring around the correct answer. diffusion osmosis respiration () (b) Suggest how the highly folded cell surface helps the epithelial cell to absorb soluble food. () (c) Epithelial cells also carry out active transport. (i) Name one food molecule absorbed into epithelial cells by active transport. () Page 24 of 88
Why is it necessary to absorb some food molecules by active transport? () Suggest why epithelial cells have many mitochondria. (2) (d) Some plants also carry out active transport. Give one substance that plants absorb by active transport. () (Total 8 marks) 4 Human cells and yeast cells have some parts that are the same. (a) The diagram shows a yeast cell. Parts A and B are found in human cells and in yeast cells. On the diagram, label parts A and B. (2) Page 25 of 88
(b) Many types of cell can divide to form new cells. Some cells in human skin can divide to make new skin cells. Why do human skin cells need to divide? () (c) Human stem cells can develop into many different types of human cell. (i) Use the correct answer from the box to complete the sentence. embryos hair nerve cells Human stem cells may come from () Use the correct answer from the box to complete the sentence. cystic fibrosis paralysis polydactyly Human stem cells can be used to treat () (Total 5 marks) Page 26 of 88
5 The diagram below shows the parts of the body that digest and absorb food. It also shows some details about the structure of the stomach. (a) Complete the table to show whether each structure is an organ, an organ system or a tissue. For each structure, tick ( ) one box. Structure Organ Organ system Tissue Stomach Cells lining the stomach Mouth, oesophagus, stomach, liver, pancreas, small and large intestine (2) (b) (i) The blood going to the stomach has a high concentration of oxygen. The cells lining the stomach have a low concentration of oxygen. Complete the following sentence. Oxygen moves from the blood to the cells lining the stomach by the process of. () Page 27 of 88
What other substance must move from the blood to the cells lining the stomach so that respiration can take place? Draw a ring around the correct answer. glucose protein starch () (iii) In which part of a cell does aerobic respiration take place? Draw a ring around the correct answer. cell membrane mitochondria nucleus () (Total 5 marks) 6 The image below shows some muscle cells from the wall of the stomach, as seen through a light microscope. (a) Describe the function of muscle cells in the wall of the stomach. (2) Page 28 of 88
(b) Figure above is highly magnified. The scale bar in Figure above represents 0. mm. Use a ruler to measure the length of the scale bar and then calculate the magnification of Figure above. Magnification = times (2) (c) The muscle cells in Figure above contain many mitochondria. What is the function of mitochondria? (2) (d) The muscle cells also contain many ribosomes. The ribosomes cannot be seen in Figure above. (i) What is the function of a ribosome? () Suggest why the ribosomes cannot be seen through a light microscope. () (Total 8 marks) Page 29 of 88
7 Our lungs help us to breathe. The image below shows the human breathing system. (a) (i) Name part A. () Give one function of the ribs. () (b) (i) Use the correct answer from the box to complete the sentence. active transport diffusion osmosis Oxygen moves from the air inside the lungs into the blood by the process of. () Use the correct answer from the box to complete the sentence. arteries capillaries veins Oxygen moves from the lungs into the blood through the walls of the. () Page 30 of 88
(iii) Inside the lungs, oxygen is absorbed from the air into the blood. Give two adaptations of the lungs that help the rapid absorption of oxygen into the blood.. 2. (2) (Total 6 marks) 8 Plants need different substances to survive. Figure shows the roots of a plant. (a) (i) Mineral ions are absorbed through the roots. Name one other substance absorbed through the roots. () Page 3 of 88
The plant in Figure has a higher concentration of mineral ions in the cells of its roots than the concentration of mineral ions in the soil. Which two statements correctly describe the absorption of mineral ions into the plant s roots? Tick ( ) two boxes. The mineral ions are absorbed by active transport. The mineral ions are absorbed by diffusion. The mineral ions are absorbed down the concentration gradient. The absorption of mineral ions needs energy. (2) (iii) The plant in Figure has roots adapted for absorption. Figure 2 shows a magnified part of a root from Figure. Describe how the root in Figure 2 is adapted for absorption. (2) Page 32 of 88
(b) The leaves of plants have stomata. What is the function of the stomata? () (c) Figure 3 shows the underside of two leaves, A and B, taken from a plant in a man s house. (i) In Figure 3, the cells labelled X control the size of the stomata. What is the name of the cells labelled X? Tick ( ) one box. Guard cells Phloem cells Xylem cells () Describe how the appearance of the stomata in leaf B is different from the appearance of the stomata in leaf A. () Page 33 of 88
(iii) The man forgets to water the plant. What might happen to the plant in the next few days if the stomata stay the same as shown in leaf A in Figure 3? () (Total 9 marks) 9 Gas exchange takes place in the lungs. The diagram shows an alveolus next to a blood capillary in a lung. The arrows show the movement of two gases, A and B. (a) (i) Draw a ring around the correct answer to complete the sentence. diffusion. Gases A and B move by osmosis. respiration. () Gas A moves from the blood to the air in the lungs. Gas A is then breathed out. Name Gas A. () (iii) Which cells in the blood carry Gas B? Draw a ring around the correct answer. platelets red blood cells white blood cells () Page 34 of 88
(b) The average number of alveoli in each human lung is 280 million. The average surface area of million alveoli is 0.25 m 2. Calculate the total surface area of a human lung. Answer m 2 (2) (c) An athlete trains to run a marathon. The surface area of each of the athlete s lungs has increased to 80 m 2. Give one way in which this increase will help the athlete. () (Total 6 marks) 20 The diagram below shows a single-celled alga which lives in fresh water. (a) Which part of the cell labelled above: (i) traps light for photosynthesis () is made of cellulose? () Page 35 of 88
(b) In the freshwater environment water enters the algal cell. (i) What is the name of the process by which water moves into cells? () Give the reason why the algal cell does not burst. () (c) (i) The alga can photosynthesise. Complete the word equation for photosynthesis. water + + oxygen (2) The flagellum helps the cell to move through water. Scientists think that the flagellum and the light-sensitive spot work together to increase photosynthesis. Suggest how this might happen. (2) (d) Multicellular organisms often have complex structures, such as lungs, for gas exchange. Explain why single-celled organisms, like algae, do not need complex structures for gas exchange. (3) (Total marks) Page 36 of 88
2 The diagram below shows a cross-section of a plant root. The transport tissues are labelled. (a) (i) What is tissue A? Draw a ring around the correct answer. cuticle epidermis xylem () Name two substances transported by tissue A.. 2. (2) (b) Phloem is involved in a process called translocation. (i) What is translocation? () Explain why translocation is important to plants. (2) Page 37 of 88
(c) Plants must use active transport to move some substances from the soil into root hair cells. (i) Active transport needs energy. Which part of the cell releases most of this energy? Tick ( ) one box. mitochondria nucleus ribosome () Explain why active transport is necessary in root hair cells. (2) (Total 9 marks) 22 Some infections are caused by bacteria. (a) The genetic material is arranged differently in the cells of bacteria compared with animal and plant cells. Describe two differences. (2) Page 38 of 88
(b) Tuberculosis (TB) is an infection caused by bacteria. The table below shows the number of cases of TB in different regions of southern England from 2000 20. Number of cases of TB per 00 000 people Year London South East South West 2000 37 5 3 200 36 6 4 2002 42 6 6 2003 42 7 4 2004 42 7 5 2005 49 8 5 2006 44 8 3 2007 43 8 5 2008 44 8 5 2009 44 9 6 200 42 9 5 20 45 0 5 (i) How does the number of cases of TB for London compare with the rest of southern England? () Describe the pattern in the data for cases of TB in the South East. () Page 39 of 88
(iii) Describe the pattern in the data for cases of TB in the South West. (2) (c) (i) On the graph paper below: plot the number of cases of TB in London label both the axes on the graph draw a line of best fit. (4) Suggest why a student thought the value for 2005 in London was anomalous. () Page 40 of 88
(d) People can be vaccinated against TB. Suggest how a vaccination programme would reduce the number of people with TB. Details of how a vaccine works are not required. (2) (Total 3 marks) 23 The lugworm lives in a U-shaped burrow in the sand on the seashore. The diagram below shows a lugworm in its burrow. Page 4 of 88
(a) Some scientists investigated the effect of different salt concentrations on lugworms. The scientists: collected 50 lugworms from the seashore separated them into five groups of 0 lugworms weighed each group of 0 lugworms placed each group into a different concentration of salt solution and left them for 8 hours took each lugworm out of the solution and placed it on blotting paper for 30 seconds re-weighed each group of 0 lugworms. (i) Why did the scientists use groups of 0 lugworms and not just lugworm at each concentration? () Suggest why the scientists placed each lugworm on blotting paper for 30 seconds before they reweighed the groups of lugworms. () (iii) How might the method of blotting have caused errors in the results? () (iv) Suggest one improvement the scientists could make to their investigation. () Page 42 of 88
(b) The table below shows the scientists results. Concentration of salt in arbitrary units Mass of 0 lugworms at start in grams Mass of 0 lugworms after 8 hours in grams Change in mass in grams Percentage (%) change in mass.0 4.2 6.8 +20.6 +50 2.0 37.5 45.0 +7.5 3.0 55.0 56. +. +2 4.0 46.2 22.2-24.0-52 5.0 45.3 22.6-22.7-50 (i) The scientists calculated the percentage change in mass at each salt concentration. Why is the percentage change in mass more useful than just the change in mass in grams? Use information from the table in your answer. (2) Calculate the percentage change in mass for the 0 lugworms in the salt solution with a concentration of 2.0 arbitrary units. Percentage change in mass = % (2) Page 43 of 88
(c) (i) On the graph paper below, draw a graph to show the scientists results: plot the percentage change in mass label the horizontal axis draw a line of best fit. (4) The scientists thought one of their results was anomalous. Draw a ring around the anomalous result on your graph. () (iii) Suggest what might have happened to cause this anomalous result. () Page 44 of 88
(d) (i) What do you think is the concentration of salts in the lugworm s natural environment? Use information from your graph to give the reason for your answer. Concentration = % Reason (2) The mass of the lugworms decreased in the salt solution with a concentration of 5.0 arbitrary units. Explain what caused this. (3) (Total 9 marks) 24 The diagram below shows how a nerve impulse passing along a relay neurone causes an impulse to be sent along another type of neurone, neurone X. Page 45 of 88
(a) What type of neurone is neurone X? () (b) Describe how information passes from the relay neurone to neurone X. Use the diagram to help you. (3) (c) Scientists investigated the effect of two toxins on the way in which information passes across synapses. The table below shows the results. Toxin Curare Strychnine Effect at the synapse Decreases the effect of the chemical on neurone X Increases the amount of the chemical made in the relay neurone Describe the effect of each of the toxins on the response by muscles. Curare Strychnine (2) (Total 6 marks) Page 46 of 88
25 The image below shows some cells in the lining of the stomach. (a) (i) Use words from the box to name structures A and B. cell membrane chloroplast cytoplasm vacuole A B (2) What is the function of the nucleus? Tick ( ) one box. To control the activities of the cell To control movement of substances into and out of the cell To release energy in respiration () Page 47 of 88
(b) Draw one line from each part of the human body to its correct scientific name. Part of human body Scientific name Layer of cells lining the stomach Stomach Mouth, stomach, intestines, liver and pancreas An organ An organism An organ system A tissue (3) (Total 6 marks) 26 In sexual reproduction, an egg fuses with a sperm. (a) (i) Draw a ring around the correct answer to complete the sentence. cloning. An egg and a sperm fuse together in the process of fertilisation. mitosis. () Egg cells and sperm cells each contain the structures given in the box. chromosome gene nucleus List these three structures in size order, starting with the smallest. (smallest) 2. 3 (largest) (2) Page 48 of 88
(iii) The egg and the sperm contain genetic material. Draw a ring around the correct answer to complete the sentence. carbohydrate. The genetic material is made of DNA. protein. () (b) The diagram below shows the inheritance of X and Y chromosomes. (i) Draw a tick ( ) on the part of the diagram that shows a sperm cell. () What is the chance of having a female child? Give the reason for your answer. (2) (Total 7 marks) 27 In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. Diffusion is an important process in animals and plants. The movement of many substances into and out of cells occurs by diffusion. Describe why diffusion is important to animals and plants. Page 49 of 88
In your answer you should refer to: animals plants examples of the diffusion of named substances. Extra space (Total 6 marks) Page 50 of 88
28 Substances can move into cells and out of cells. (a) Draw a ring around the correct answer to complete each sentence. active transport. Water moves into cells and out of cells by osmosis. reabsorption. freely permeable The water moves through a non-permeable membrane. partially permeable (2) (b) Students put plant cells into two different strengths of sugar solutions, A and B. The diagram below shows what the cells looked like after hour. Cell in sugar solution A (after hour) Cell in sugar solution B (after hour) (i) Describe two ways in which the cell in sugar solution B is different from the cell in sugar solution A.. 2. (2) Page 5 of 88
A student put red blood cells into water. Suggest what would happen to the cells. () (c) In the human body, glucose is absorbed into the blood from the small intestine. The small intestine contains many villi. Which two of the following help the absorption of glucose in the small intestine? Tick ( ) two boxes. Villi have a cell wall. Villi are covered in thick mucus. Villi give the small intestine a large surface area. Villi have many blood capillaries. (2) (Total 7 marks) 29 Plant roots absorb water from the soil by osmosis. (a) What is osmosis? (3) Page 52 of 88
(b) The image below shows part of a plant root. The plant root is adapted for absorbing water from the soil. Use information from the diagram to explain how this plant root is adapted for absorbing water. (3) (Total 6 marks) Page 53 of 88
30 The diagram shows a cell. (a) (i) Use words from the box to name the structures labelled A and B. cell membrane chloroplast cytoplasm nucleus A B (2) The cell in the diagram is an animal cell. How can you tell it is an animal cell and not a plant cell? Give two reasons.. 2. (2) (b) Oxygen will diffuse into the cell in the diagram. Why? Use information from the diagram. () Page 54 of 88
(c) The cell shown in the diagram is usually found with similar cells. Draw a ring around the correct answer to complete the sentence. an organ. Scientists call a group of similar cells a system. a tissue. () (Total 6 marks) 3 CADASIL is an inherited disorder caused by a dominant allele. CADASIL leads to weakening of blood vessels in the brain. The diagram shows the inheritance of CADASIL in one family. (a) CADASIL is caused by a dominant allele. (i) What is a dominant allele? () What is the evidence in the diagram that CADASIL is caused by a dominant allele? () Page 55 of 88
(iii) Person 7 has CADASIL. Is person 7 homozygous or heterozygous for the CADASIL allele? Give evidence for your answer from the diagram. () (b) Persons 7 and 8 are planning to have another baby. Use a genetic diagram to find the probability that the new baby will develop into a person with CADASIL. Use the following symbols to represent alleles. D = allele for CADASIL d = allele for not having CADASIL Probability = (4) (c) Scientists are trying to develop a treatment for CADASIL using stem cells. Specially treated stem cells would be injected into the damaged part of the brain. (i) Why do the scientists use stem cells? (2) Page 56 of 88
Embryonic stem cells can be obtained by removing a few cells from a human embryo. In 2006, scientists in Japan discovered how to change adult skin cells into stem cells. Suggest one advantage of using stem cells from adult skin cells. () (Total 0 marks) 32 The diagram shows some of the stages in IVF (in vitro fertilisation). (a) Use words from the box to name structures A, B, C and D. egg embryo fertilised egg ovary sperm Structure A Structure B Structure C Structure D (4) (b) What do doctors do next with structure D? (2) Page 57 of 88
(c) The table gives statistics for an IVF clinic. Age of women treated Below 35 years 35 37 years 38 39 years 40 42 years Number of women treated 44 207 06 53 Number of women who produced one baby 90 43 7 Number of women who produced twins 24 8 4 Number of women who produced triplets 0 0 0 (i) About what proportion of the treated women aged 35 37 years produced one or more babies? Draw a ring around your answer. one quarter one third half () This clinic does not give IVF treatment to women over 42 years of age. Use data from the table to explain why. (2) (iii) The committee which regulates IVF treatment now advises that only one embryo is used in each treatment. Suggest one reason for this. () (Total 0 marks) Page 58 of 88
33 The diagrams show four types of cell, A, B, C and D. Two of the cells are plant cells and two are animal cells. (a) (i) Which two of the cells are plant cells? Tick ( ) one box. A and B A and D C and D () Give one reason for your answer. () Page 59 of 88
(b) (i) Which cell, A, B, C or D, is adapted for swimming? () Which cell, A, B, C or D, can produce glucose by photosynthesis? () (c) Cells A, B, C and D all use oxygen. For what process do cells use oxygen? Draw a ring around one answer. osmosis photosynthesis respiration () (Total 5 marks) 34 Substances can move into and out of cells. (a) (i) How does oxygen move into and out of cells? Draw a ring around one answer. diffusion digestion photosynthesis () Diagram shows the percentage concentration of oxygen in three cells, A, B and C. Diagram Oxygen can move from cell to cell. Into which cell, A, B or C, will oxygen move the fastest? () Page 60 of 88
(b) (i) How does water move into and out of cells? Draw a ring around one answer. breathing osmosis respiration () Differences in the concentration of sugars in cells cause water to move into or out of cells at different rates. Diagram 2 shows three different cells, P, Q and R. The information shows the percentage concentration of sugar solution in cells P, Q and R. Diagram 2 Water can move from cell to cell. Into which cell, P, Q or R, will water move the fastest? () (Total 4 marks) Page 6 of 88
35 Diagrams A, B and C show cells from different parts of the human body, all drawn to the same scale. A B C (a) Which cell, A, B or C, appears to be best adapted to increase diffusion into or out of the cell? Give one reason for your choice. () (b) (i) Cell C is found in the salivary glands. Name the enzyme produced by the salivary glands. () Use information from the diagram to explain how cell C is adapted for producing this enzyme. (2) (Total 4 marks) Page 62 of 88
Mark schemes (a) cell membrane extra boxes ticked negates mark (b) nucleus extra boxes ticked negates mark (c) (d) has a tail so it can swim (to an egg) accept has many mitochondria to release energy to swim all three correct for 2 marks one or two correct for mark 2 [5] 2 (a) 8 (micrometres) (b) red blood cell(s) white blood cell(s) accept named cell eg phagocyte / lymphocyte Page 63 of 88
(plasma) transports proteins / dissolved substances / food (molecules) / urea / hormones / blood cells (c) any one from: you could lose a lot of blood bleed internally allow bleeding would not stop allow could bleed to death [5] 3 (a) mitosis extra box ticked negates mark (b) (c) cell division is uncontrolled any one from: smoking / tar alcohol carcinogens extra box ticked negates mark allow named chemical viruses (living in cells) (ionising) radiation accept UV / X-rays / gamma waves (d) bar plotted at 78% ignore width of bar (e) testicular extra box ticked negates mark (f) prostate extra box ticked negates mark Page 64 of 88
(g) any two from: improved treatment / drugs earlier diagnosis more cancer screening improved patient knowledge (of risk factors) allow improved patient diet / lifestyle 2 [8] 4 (a) (b) (c) (trachea) has mucus to trap pathogens (trachea) has cilia to move mucus out of trachea dependent variable: number of times mosquitoes landed on socks 3 Page 65 of 88
control variable: any one from: (d) (e) number of mosquitoes in each container length of time socks worn dampness of socks same type of socks size of container time temperature species of mosquito age of mosquito use worn socks or use chemical from worn socks to attract / trap infected mosquitoes or accept: wear clean socks / change socks regularly () to reduce the chance of attracting mosquitoes () less chlorophyll present (so) less light absorbed (so) reduced photosynthesis or (so) less sugar / food made [4] 5 (a) D any one from: has chloroplasts has a (large) vacuole ignore has a (cell) wall (b) B does not have a (cell) wall allow has only a nucleus, (cell) membrane and cytoplasm Page 66 of 88
(c) C any one from: genetic material is not in a nucleus allow no nucleus has a single loop of DNA (d) real size = 25 / 00 000 0.00025 (conversion to) 0.25 (µm) allow 0.25 (µm) with no working shown for 3 marks [9] 6 (nitrate) ions are absorbed by active transport (active transport) is the movement of ions against the concentration gradient allow (active transport) is the movement of ions from a dilute to a more concentrated solution (active transport) requires energy from respiration (respiration) requires oxygen no / little oxygen / air in water-logged soil [5] 7 (a) animal cells also have cell membrane (b) 945 955 allow 946 956 or 947 957 (c) 9. (%) allow 9.09 (%) or 9 (%) with no working shown for mark allow 9. (%) with no working shown for 2 marks Page 67 of 88
(d) More likely Less likely allow 3 marks for 4 correct allow 2 marks for 3 correct allow mark for 2 correct more than one tick in a row negates a mark 4 [8] 8 (a) asexual reproduction (b) mitosis (c) clones (d) 44 [4] 9 (a) (placed) randomly allow description of placement sufficient number (of quadrats) used count (dandelions) in each quadrat use mean number of dandelions, area of quadrat and area of field to estimate population accept (area of field / area quadrat) mean number of dandelions per quadrat (b) (40 45) / 0.25 = 23 200 Page 68 of 88
(0.42 23 200 =) 9744 allow 9744 with no working shown for 2 marks allow ecf from correct attempt at the previous step) 0.42 for mark (c) Level 2 (3 4 marks): A detailed and coherent explanation is given. Logical links between clearly identified relevant points are made to explain why dandelion growth may be limited. Level ( 2 marks): Discrete relevant points are made. The logic may be unclear. 0 marks: No relevant content Indicative content factors that may be considered: competition for resources including: light water space mineral ions (allow nutrients / salts / ions from the soil) reference to why growth may be limited: (light) energy for photosynthesis water as a raw material for photosynthesis / support surface area exposed to light sugar / glucose produced in photosynthesis (space) to grow bigger (space) for growth of root system (mineral ions) for growth (mineral ions / sugar) for production of larger molecules or named example 4 [0] 0 (a) human cells have cell membrane or human cells have no cell wall (b) can no longer synthesise proteins (c) antibiotics are being developed at a slower rate than emergence of new resistant strains resistant strains mean we cannot treat (common) infections reduce (future) cost of antibiotic resistant infections [5] Page 69 of 88
(a) = 29 0.03 = 967 allow 967 with no working shown for 2 marks (b) (c) (d) they are transverse wave speed = frequency wavelength allow v = f λ 75 cm = 0.75 m.6 = f 0.75 f =.6 0.75 = 2.3 (Hz) allow 2.3 (Hz) with no working shown for 4 marks [8] Page 70 of 88
2 (a) Mitosis only Meiosis only Both mitosis and meiosis How cells are replaced How gametes are made How a fertilised egg undergoes cell division How copies of the genetic information are made How genetically identical cells are produced if more than one tick per row then no mark ignore first row (b) (i) (adult) bone marrow accept (umbilical) cord blood, skin, amniotic fluid / membrane cells will not be rejected by the patient s body (if they have been produced by therapeutic cloning) allow easier to obtain linked to embryo stem cells or (embryo stem cells) can develop into many different types of cells allow doesn t need an operation linked to bone marrow or (embryo stem cells) not yet differentiated / specialised or undifferentiated accept embryo cells are pluripotent [6] Page 7 of 88
3 (a) (i) nucleus diffusion (b) increases / larger surface area (for diffusion) ignore large surface area to volume ratio (c) (i) sugar / glucose accept amino acids / other named monosaccharides (iii) against a concentration gradient or from low to high concentration (active transport requires) energy (from) respiration (d) minerals / ions accept named ion ignore nutrients do not accept water [8] 4 (a) A = nucleus allow phonetic spelling B = (cell) membrane (b) for repair / growth or to replace cells ignore new cells / skin (c) (i) embryos paralysis [5] Page 72 of 88
5 (a) Structure Organ Organ system Tissue Stomach Cells lining the stomach Mouth, oesophagus, stomach, liver, pancreas, small and large intestine all 3 correct = 2 marks 2 correct = mark or 0 correct = 0 marks (b) (i) diffusion allow phonetic spelling 2 glucose (iii) mitochondria [5] 6 (a) contract / shorten ignore relax do not allow expand to churn / move / mix food accept peristalsis / mechanical digestion ignore movement unqualified (b) 400 acceptable range 390-40 allow mark for answer in range of 39 to 4 allow mark for answer in range of 3900 to 400 2 (c) to transfer energy for use allow to release / give / supply / provide energy do not allow to make / produce / create energy allow to make ATP ignore to store energy Page 73 of 88
by (aerobic) respiration or from glucose do not allow anaerobic energy released for respiration = max mark (d) (i) to make protein / enzyme ignore antibody or other named protein too small / very small allow light microscope does not have sufficient magnification / resolution allow ribosomes are smaller than mitochondria ignore not sensitive enough ignore ribosomes are transparent [8] 7 (a) (i) alveoli / alveolus allow air sacs allow phonetic spelling any one from: protection (of lungs / heart) help you breathe / inflate lungs. (b) (i) diffusion (iii) capillaries any two from: (have many) alveoli allow air sacs large surface / area thin (exchange) surface or short diffusion pathway accept only one / two cell(s) thick good blood supply / many capillaries allow (kept) ventilated or maintained concentration gradient. 2 [6] Page 74 of 88
8 (a) (i) water / H 2 O accept oxygen allow H 2 O do not allow H 2 O or H2O (iii) the mineral ions are absorbed by active transport the absorption of mineral ions needs energy have (many root) hairs (which) give a large surface area (for absorption) (b) carbon dioxide in or oxygen out or control water loss accept gas exchange ignore gases in and out ignore gain / lose water (c) (i) guard cells (iii) (stomata are) closed allow there is no gap / space plant will wilt / droop ignore die [9] 9 (a) (i) diffusion carbon dioxide accept CO 2 / CO2 do not accept CO 2 (iii) red blood cells Page 75 of 88
(b) 70 if no / incorrect answer then 70 000 000 or 280 x 0.25 gains mark ignore doubling the answer 2 (c) allows more gas / oxygen / CO 2 (exchange) do not accept air [6] 20 (a) (i) chloroplast cell wall (b) (i) osmosis accept diffusion cell wall (prevents bursting) (c) (i) carbon dioxide allow correct formula glucose allow sugar / starch any two from: (d) light sensitive spot detects light tells flagellum to move towards light more light = more photosynthesis (cell has) larger SA:volume ratio short (diffusion) distance allow correct description 2 Page 76 of 88
(diffusion) via cell membrane is sufficient / good enough or flow of water maintains concentration gradient [] 2 (a) (i) xylem water minerals / ions / named example(s) ignore nutrients (b) (i) movement of (dissolved) sugar allow additional substances, eg amino acids / correct named sugar (allow sucrose / glucose) allow nutrients / substances / food molecules if sufficiently qualified ignore food alone sugars are made in the leaves so they need to be moved to other parts of the plant for respiration / growth / storage (c) (i) mitochondria for movement of minerals / ions Do not accept water against their concentration gradient [9] 22 (a) any two from: only one chromosome allow one strand of DNA circular allow loop may have plasmids not in a nucleus / no nucleus 2 Page 77 of 88
(b) (i) any one from: (iii) London is much higher or converse more variable / wider range increases allow on average it is 5 / 6 times greater Included figures must be correct overall slight increase accept doesn t change much variable / goes up and down (c) (i) both axes correctly labelled x = Year y = Number of cases correct points all correct = 2 marks -2 errors = mark > 2 errors = 0 marks suitable line of best fit accept straight line or smooth curve doesn t fit the pattern / line of best fit 2 (d) provides immunity / protection (to TB) ignore stops people catching it ignore resistance prevents TB spreading accept ref to herd immunity [3] Page 78 of 88
23 (a) (i) variation in masses / more representative / more typical / more reliable / average / mean / reference to anomalies or (iii) one worm to light to measure change do not allow more accurate / more precise ignore fair test / valid / repeatable / reproducible remove solution / liquid (on outside of worm) allow water variable amounts removed from each worm ignore reference to length of timing (iv) equal sizes of worm / more worms (in each group) / wash off all the sand / repeats / use more accurate balance / use smaller concentration intervals allow reference to improve blotting technique eg blot before / blot more thoroughly (b) (i) different (starting) masses / sizes / weights (at different concentrations) allows comparisons / shows pattern / shows trend (+)20 correct answer = 2 marks, with or without working or for mark 2 (c) (i) graph: points correct allow ± mm mark per error allow ecf from part b label on x-axis including units ie Concentration of salt in arbitrary units 2 Page 79 of 88
line of best fit = smooth curve / ruled straight line anomaly (4.0, 52) either plotted and ignored re. line or not plotted do not allow point to point allow best fit for ecf from 2bii on graph: ring drawn around point at (4.0, 52) allow (5.0, 50) if cand. line indicates this (iii) sensible suggestion eg used wrong solution / used 5.0% instead of 4.0% / different length of time in solutions / ref to error in blotting / balance not zeroed / error in weighing allow some lugworms died allow error in calculation (d) (i) 2.9 to 3.0 / correct for candidate s graph ± 0. value of no change in mass / worms in equilibrium with soln / described allow small(est) mass change water loss by osmosis / diffusion from dilute region in the worm to more concentrated solution outside allow correct description in terms of high to low water concentration / high to low water potential salt solution is hypertonic concentration unqualified = salt concentration [9] 24 (a) motor allow efferent / postsynaptic allow another relay (neurone) (b) release of chemical (from relay neurone) allow ecf for motor neurone from (a) allow release of neurotransmitter / named example Page 80 of 88
(c) chemical crosses gap / junction / synapse allow diffuses across allow chemical moves to X chemical attaches to X / motor / next neurone (causing impulse) (curare) decrease / no contraction accept (muscle) relaxes (strychnine) increase / more contraction if no other mark awarded allow mark for (curare) decrease / no response and (strychnine) increase / more response [6] 25 (a) (i) A = (cell) membrane B = cytoplasm do not accept cytoplast To control the activities of the cell (b) extra lines cancel 3 [6] 26 (a) (i) fertilisation Page 8 of 88
in sequence: accept next to gene, 2 next to chromosome and 3 next to nucleus in box (iii) gene 2 chromosome 3 nucleus DNA allow mark for smallest or largest in correct position 2 (b) (i) On diagram: tick drawn next to X and / or Y from Parent tick(s) must be totally outside grid squares allow ticks around parent extra ticks elsewhere cancel 0.5 / ½ / 50% / : / 50:50 / in 2 allow 2/4 / 2 in 4 / 2 out of 4 / even(s) / fifty fifty do not allow :2 or 50 / 50 or 50 50 2 (out of 4) boxes are XX or half of the sperm contain an X-chromosome allow XY is male and 2 (out of 4) boxes are XY [7] Page 82 of 88
27 Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also apply a best-fit approach to the marking. 0 marks No relevant content. Level ( 2 marks) An example is given of a named substance or a process or there is an idea of why diffusion is important eg definition. Level 2 (3 4 marks) At least one example of a substance is given and correctly linked to a process in either animals or plants. Level 3 (5 6 marks) There is a description of a process occurring in either animals or plants that is correctly linked to a substance and a process occurring in the other type of organism that is correctly linked to a substance. examples of points made in the response Importance of diffusion: to take in substances for use in cell processes products from cell processes removed Examples of processes and substances: for gas exchange / respiration: O 2 in / CO 2 out for gas exchange / photosynthesis: CO 2 in / O 2 out food molecules absorbed: glucose, amino acids, etc water absorption in the large intestine water lost from leaves / transpiration water absorption by roots mineral ions absorbed by roots extra information Description of processes might include: movement of particles / molecules / ions through a partially permeable membrane (movement of substance) down a concentration gradient osmosis: turgor / support / stomatal movements [6] Page 83 of 88
28 (a) osmosis partially permeable (b) (i) any two from: allow correct answers in terms of A vacuole is small(er) cytoplasm has shrunk allow cytoplasm is smaller gap between cytoplasm and cell wall cell wall curves inwards allow cell B is flaccid or cell A is turgid the (cell) membrane has moved away from the wall 2 any one from: (c) water will move / diffuse in (cells) will swell (cells) will burst ignore turgid villi give the small intestines a large surface area villi have many blood capillaries [7] 29 (a) any three from: (water through a) partially permeable accept semi permeable / selectively permeable membrane from dilute to (more) concentrated solution allow from a high concentration of water to a lower concentration (of water) allow from high water potential to low water potential allow down a concentration gradient of water do not accept along a concentration gradient of water (it s a) passive (process) allow requires no energy 3 Page 84 of 88
(b) (there are) many hairs or thin hairs or hairs are one cell thick (which gives) large / increased surface area or short diffusion pathway (so there is) more diffusion / osmosis (of water into the root) ignore absorption [6] 30 (a) (i) A = nucleus B = (cell) membrane any two from: ignore shape no (cell) wall no (large / permanent) vacuole no chloroplasts / chlorophyll 2 (b) because high to low oxygen / concentration or down gradient allow more / a lot of oxygen molecules outside ignore along / across gradient (c) a tissue [6] 3 (a) (i) allele expressed even when other allele present or expressed if just one copy of allele is present or expressed if heterozygous if present other allele not expressed 2 affected parents have unaffected child or and 2 5 / 6 or if recessive all of and 2 s children would have CADASIL (iii) heterozygous has unaffected children or because if homozygous all children would have CADASIL (b) genetic diagram including: accept alternative symbols, if defined Page 85 of 88
correct gametes: D and d and d (and d) ignore 7 / 8 or male / female derivation of offspring genotypes: Dd Dd dd dd allow just Dd dd if ½-diagram allow ecf if correct for student s gametes identification of Dd as CADASIL or dd as unaffected allow ecf if correct for student s gametes correct probability: 0.5 / ½ / in 2 / 50% / : (c) (i) stem cells can differentiate or are undifferentiated / unspecialised can form blood vessel cells / brain cells or stem cells can divide ethical argument - eg no risk of damage to embryo or adult can give consent for removal of cells or adult can re-grow skin more ethical qualified ignore religion unqualified or if from a relative then less chance of rejection or if from self then no chance of rejection or skin cells more accessible [0] 32 (a) A sperm B egg C fertilised egg Page 86 of 88
(b) D embryo insert into mother ignore fertilise / check fertilisation / check viability womb / uterus (c) (i) one quarter no / little chance of success over 42 reference to table of only two women in the age bracket 40-42 years became pregnant the statement only 2 out of 53 40-42 year old women became pregnant / had babies gains 2 marks (iii) so fewer twins / multiple births or multiple births more dangerous [0] 33 (a) (i) C and D no mark if more than one box is ticked any one from: do not allow if other cell parts are given in a list (have) cell wall(s) (have) vacuole(s) (b) (i) A apply list principle D apply list principle (c) respiration apply list principle [5] Page 87 of 88
34 (a) (i) diffusion apply list principle A apply list principle (b) (i) osmosis apply list principle R apply list principle [4] 35 (a) B no mark for B alone, the mark is for B and the explanation. large(r) surface / area or large(r) membrane accept reference to microvilli ignore villi / hairs / cilia accept reasonable descriptions of the surface eg folded membrane / surface do not accept wall / cell wall (b) (i) any one from: (salivary) amylase carbohydrase many ribosomes do not mix routes. If both routes given award marks for the greater. ribosomes produce protein accept amylase / enzyme / carbohydrase is made of protein or (allow) many mitochondria () mitochondria provide energy to build / make protein () accept ATP instead of energy [4] Page 88 of 88