Biology 9700 · AS & A Level
Oct/Nov 2011
120 questions from this paper, with worked solutions and instant marking.
What diameter is typical for a prokaryote such as Streptococcus?
Cells as the basic units of living organisms
Solutions containing biological molecules are tested for sugars. The table gives the colours observed in the solutions after the test. Which could contain reducing sugars?
Testing for biological molecules
Which characteristic of water makes it especially suitable for transport in eukaryotic organisms?
Water
Which statements about the effects of all enzyme inhibitors are correct?
Factors that affect enzyme action
The graph illustrates how an enzyme affects a reaction. Which option identifies X, Y and Z?
Mode of action of enzymes
Single-celled animals living in fresh water possess a vacuole that contracts at regular intervals to eliminate extra water. Single-celled plants living in fresh water do not have an equivalent vacuole. Which statement explains why only these animals need this vacuole?
Movement into and out of cells
Which statement gives the definition of active transport?
Movement into and out of cells
Which of these statements about the components of the cell surface membrane are correct?
Fluid mosaic membranes
Which statement concerning a diploid cell is not true?
Replication and division of nuclei and cells
Meiosis and mitosis are two forms of cell division. Before division, a cell contains 10 chromosomes. After it has divided by meiosis or mitosis, how many chromosomes will it contain?
Replication and division of nuclei and cells
A gene provides the instructions for making the protein p53, which attaches to damaged DNA while replication is taking place and stops that DNA from being copied. A carcinogen found in cigarette smoke mutates this gene. Which statement explains why this mutation may lead to cancer?
Replication and division of nuclei and cells
Which parts of a cell contain ribosomes?
Cells as the basic units of living organisms
During a genetic engineering experiment, a section of double-stranded DNA with 6000 nucleotides that codes for a specific polypeptide is transcribed and then translated. How many amino acids are there in total in this polypeptide?
Proteins
What allows DNA molecules to be replicated exactly?
Replication and division of nuclei and cells
Which molecule’s production is directly controlled by DNA?
Proteins
Bacteria were cultured in a medium that contained $^{15}\text{N}$. After a few generations, every bacterium contained $^{15}\text{N}$. Some of these bacteria were then moved into a medium containing the nitrogen isotope $^{14}\text{N}$. The bacteria were permitted to divide once. DNA was taken from some of these bacteria and examined. This DNA consisted entirely of hybrid DNA with equal quantities of $^{14}\text{N}$ and $^{15}\text{N}$. The rest of the bacteria were kept in the $^{14}\text{N}$ medium and allowed to divide once again. DNA from some of these bacteria was then extracted and analysed. What is the composition of this DNA?
Replication and division of nuclei and cells
The diagram illustrates how pressure in the left side of the heart and the aorta varies with time. This cardiac cycle lasts $0.6\,\text{s}$. Points $1$, $2$, $3$ and $4$ show when the atrio-ventricular valves and the semi-lunar valves open or close. What is the total length of time in one cardiac cycle for which the atrio-ventricular valves and the semi-lunar valves are both closed together?
The heart
The large arteries near the heart have a thick elastic layer in their walls. Which of the following statements about this layer are correct?
Proteins
The diagram illustrates the role of red blood cells in transporting carbon dioxide. Which row is correct?
Movement into and out of cells
Which blood components are also found in lymph?
The circulatory system
Under which combination of environmental conditions are the stomata of a plant most likely to be open?
Movement into and out of cells
The diagram shows the tissues involved in the transport of sucrose in a plant. In which part is the sucrose concentration highest?
Movement into and out of cells
In which part of a cell would cristae be located?
Cells as the basic units of living organisms
Which evidence provides support for the cohesion-tension theory of water transport in plants?
The microscope in cell studies
Which statement explains the way smoking contributes to cardiovascular disease?
The microscope in cell studies
In which part of the respiratory system are both goblet cells and ciliated epithelium present?
The gas exchange system
What is one consequence of inhaling tobacco smoke?
The microscope in cell studies
Which of the following does not improve the efficiency of gaseous exchange in the alveoli?
Movement into and out of cells
Which of the following details are correct?
Cells as the basic units of living organisms
In which places are antibodies and antigens located?
Proteins
Breast milk made by the mother for a new-born baby includes antibodies. What do these antibodies give?
Proteins
Which group could count as a population?
The microscope in cell studies
Which box includes only the components of an ecosystem that are classified as a food web?
Transport mechanisms
Which cell structures are found in every prokaryotic cell?
Cells as the basic units of living organisms
The graph illustrates the yearly variation of these factors in a lake: intensity of light per day; numbers of producers; numbers of primary consumers; quantity of nutrients. Which curve shows the numbers of primary consumers?
Transport mechanisms
The diagram depicts a stage micrometer whose small divisions are $0.1\,\text{mm}$, observed using an eyepiece fitted with a graticule. The stage micrometer is then swapped for a slide of a plant cell. What is the length of the nucleus?
The microscope in cell studies
Why do eukaryotic cells usually divide more slowly than prokaryotic cells?
Replication and division of nuclei and cells
Which type of bonding in proteins is the strongest?
Proteins
Maltose and sucrose are two disaccharides. Maltose is made from two glucose molecules, whereas sucrose is made from glucose and fructose. Which row gives the molecular formulae of these two disaccharides?
Carbohydrates and lipids
The diagram depicts a carbohydrate molecule. Which polymers could it be a component of?
Carbohydrates and lipids
What is the usual diameter of a plant cell?
Cells as the basic units of living organisms
Solutions of biological molecules are examined for sugars. The table shows the colours of the solutions after the test. Which could contain non-reducing sugars?
Testing for biological molecules
As a lake starts to ice over, which features of water are necessary for fish to remain alive? 1 Water has a large surface tension. 2 Water possesses a high latent heat of vaporisation. 3 Water has a large thermal capacity. 4 Water reaches its greatest density at $4^\circ\text{C}$.
Water
In an enzyme-catalysed reaction, which pairing of inhibitor and substrate would produce the greatest rate of reaction?
Factors that affect enzyme action
After a heart attack, the enzyme lactate dehydrogenase enters the blood plasma from injured heart muscle. Which steps are needed to obtain the most accurate estimate of lactate dehydrogenase activity in a sample of blood plasma?
Factors that affect enzyme action
Red blood cells were immersed in a sodium chloride solution that had a less negative water potential than the cell contents. Haemoglobin escaped from the cells. By which process was the haemoglobin released?
Movement into and out of cells
The table presents three processes that help movement across cell-surface membranes. Which of these processes occur because molecules move randomly?
Movement into and out of cells
As the weather becomes colder, the cell surface membranes of plants adapted to cold conditions alter, enabling the plants to perform exocytosis. Which change takes place?
Fluid mosaic membranes
Which of the following statements concerning a diploid cell are correct? 1 can divide by mitosis in order to repair itself 2 has two full sets of chromosomes 3 carries out a reduction division to produce haploid cells 4 carries out mitotic division so that growth can take place
Replication and division of nuclei and cells
Meiosis and mitosis are two kinds of cell division. A cell contains 20 chromosomes before division. How many chromosomes will it have after it divides by meiosis or mitosis?
Replication and division of nuclei and cells
The graph illustrates how the length of the spindle fibres changes during mitosis. Which part of the graph indicates the point at which the centromeres separate from the spindle fibres?
Chromosome behaviour in mitosis
In which part of a cell would cisternae be located?
Cells as the basic units of living organisms
In a genetic engineering investigation, a double-stranded DNA segment containing $12 \times 10^3$ nucleotides that codes for a particular polypeptide is transcribed and then translated. What is the total number of amino acids in this polypeptide?
Proteins
What is the correct order of the stages involved in enzyme formation in a cell?
Proteins
The diagram illustrates a section of a DNA molecule. Which row correctly names the structures labelled 1, 2, 3 and 4?
The microscope in cell studies
Bacteria were cultured in a medium that contained $^{15}\text{N}$. After several generations, all of them contained $^{15}\text{N}$. A number of these bacteria were then moved to a medium containing the nitrogen isotope $^{14}\text{N}$. The bacteria were allowed to divide once. DNA from some of the bacteria was extracted and analysed. This DNA was entirely hybrid DNA, with equal amounts of $^{14}\text{N}$ and $^{15}\text{N}$. Some bacteria from the medium with $^{15}\text{N}$ were transferred to a medium of $^{14}\text{N}$. They were allowed to divide twice. The graph shows the percentages of $^{14}\text{N}$ and $^{15}\text{N}$ in the DNA of these bacteria. Some bacteria from the medium with $^{15}\text{N}$ were transferred to a medium of $^{14}\text{N}$. They were allowed to divide three times. What would be the percentages of $^{14}\text{N}$ and $^{15}\text{N}$ in the DNA extracted from these bacteria?
Replication and division of nuclei and cells
The diagram illustrates pressure changes in the aorta, left atrium and left ventricle throughout the cardiac cycle. Which row describes the changes in the left ventricle at different points on the graph?
The heart
Which row indicates how the concentration changes in the red blood cells as carbon dioxide diffuses away from respiring cells?
Movement into and out of cells
The list below includes all structural parts found in blood vessels. 1 collagen fibres 2 elastic fibres 3 endothelial cells 4 smooth muscle cells Which row indicates how these components are distributed in the different blood vessels?
The microscope in cell studies
Which blood components are found in tissue fluid as well? Key: $\checkmark$ = found, $\times$ = not found
Movement into and out of cells
The diagram illustrates a longitudinal section of transport tissue in a plant stem. What are the names of element X and the tissue in which it occurs?
Structure of transport tissues
The diagram illustrates the tissues in the transport system of flowering plants. At which point is the water potential most negative?
Movement into and out of cells
Ribosomes are made up of separate subunits that join together during protein synthesis. What are these subunits made of?
Protein synthesis
Which evidence supports the theory of water movement by root pressure in flowering plants?
The microscope in cell studies
Cardiovascular disease is described as multifactorial. What is meant by this?
The circulatory system
The first diagram depicts a spirometer, an instrument used to measure changes in lung volume. During exhalation, the cover moves up, and during inhalation it moves down, creating a record on a rotating drum. The second diagram shows a typical spirometer trace. Which trace would show the vital capacity?
The gas exchange system
Which row identifies the correct positions of cartilage and smooth muscle in the human gas exchange system?
The gas exchange system
Which observation would show a difference in the structure of the gas exchange system of a cigarette smoker and a non-smoker?
The gas exchange system
Which row is the correct one?
Testing for biological molecules
Why does passive immunity remain effective for only a short period?
Proteins
What is the immune system’s initial reaction to a pathogen?
The immune system
In an ecosystem, there are only a few top consumers in a food chain. Which statement accounts for this?
Carbohydrates and lipids
The diagram illustrates energy transfer through a food chain. Values are given in $\text{kJ m}^{-2}\ \text{year}^{-1}$. What percentage of light energy is converted to net primary productivity?
The microscope in cell studies
Which cell components hold mRNA?
Protein synthesis
The diagram illustrates part of the nitrogen cycle. In soil that drains badly, which process is increased?
Water
The diagram depicts a stage micrometer with small divisions of $0.1\,\text{mm}$ viewed through an eyepiece fitted with a graticule. The stage micrometer is then exchanged for a slide of a plant cell. What is the width of a chloroplast?
The microscope in cell studies
In eukaryotes and prokaryotes, which processes occur?
Protein synthesis
At high concentrations, urea breaks every bond except covalent bonds in protein molecules. Which level of protein structure would stay unchanged when a protein is exposed to urea?
Proteins
Cellobiose and sucrose are two disaccharides. Cellobiose is made from two glucose molecules, whereas sucrose is made from glucose and fructose. Which row gives the molecular formulae of these two disaccharides?
Carbohydrates and lipids
The diagram depicts a section of a carbohydrate molecule. Which polymers might it form part of?
Carbohydrates and lipids
Which group might be a population?
Infectious diseases
In which part of the respiratory system are goblet cells and ciliated epithelium both present?
The gas exchange system
Which of the following does not improve the efficiency of gaseous exchange in the alveoli?
Movement into and out of cells
What is one consequence of breathing in tobacco smoke?
The gas exchange system
Which statement describes how smoking contributes to cardiovascular disease?
The circulatory system
Which details are accurate?
Cells as the basic units of living organisms
In what locations are antibodies and antigens found?
Proteins
Breast milk made by the mother for a newly born baby contains antibodies. What do these antibodies give?
Proteins
Which characteristic of water makes it most suitable for transport in eukaryotic organisms?
Water
The diagram illustrates a carbohydrate molecule. Which polymers might this be part of?
Carbohydrates and lipids
Maltose and sucrose are two disaccharides. Maltose is made from two glucose molecules, whereas sucrose is made from glucose and fructose. Which row gives the molecular formulae of these two disaccharides?
Carbohydrates and lipids
The graph illustrates the yearly variation in the following factors in a lake. intensity of light per day numbers of producers numbers of primary consumers quantity of nutrients Which curve shows the numbers of primary consumers?
The microscope in cell studies
What is the strongest type of bonding present in proteins?
Proteins
Samples of biological molecules are examined for sugars. The table gives the conditions used and the outcomes after each test. Solution 1: heated with Benedict’s solution → blue; boiled with hydrochloric acid, neutralised, then heated with Benedict’s solution → yellow. Solution 2: heated with Benedict’s solution → green; boiled with hydrochloric acid, neutralised, then heated with Benedict’s solution → orange. Solution 3: heated with Benedict’s solution → orange; boiled with hydrochloric acid, neutralised, then heated with Benedict’s solution → red. Which may contain reducing sugars?
Testing for biological molecules
The graph illustrates the effect of an enzyme on a reaction. Which combination identifies X, Y and Z?
Mode of action of enzymes
Which of the following statements about the effect of all enzyme inhibitors are correct?
Factors that affect enzyme action
Which statement is the definition of active transport?
Movement into and out of cells
Single-celled animals living in fresh water possess a vacuole that contracts at regular intervals to expel extra water. Single-celled plants living in fresh water do not have a comparable vacuole. Which statement accounts for why only these animals require this vacuole?
Movement into and out of cells
Which statements concerning the parts of the cell surface membrane are correct?
Fluid mosaic membranes
Which statement concerning a diploid cell is not true?
Chromosome behaviour in mitosis
Meiosis and mitosis are two kinds of cell division. Before it divides, a cell contains 10 chromosomes. How many chromosomes will it have after division by meiosis or mitosis?
Replication and division of nuclei and cells
What enables DNA molecules to be copied precisely?
Replication and division of nuclei and cells
Which box includes only those parts of an ecosystem that are classified as a food web?
Cells as the basic units of living organisms
Which molecule has its production directly controlled by DNA?
Proteins
A gene instructs cells to produce a protein, p53, which attaches to damaged DNA when cell division occurs and stops it from being replicated. A carcinogen found in cigarette smoke mutates this gene. Which statement explains why this mutation may cause cancer?
Replication and division of nuclei and cells
During a genetic engineering experiment, a double-stranded DNA fragment with 6000 nucleotides that codes for a particular polypeptide is transcribed and then translated. How many amino acids are present in total in this polypeptide?
Proteins
Bacteria were cultured in a medium containing $^{15}\text{N}$. After a number of generations, every DNA molecule contained $^{15}\text{N}$. Some of the bacteria were then moved to a medium containing the common nitrogen isotope, $^{14}\text{N}$. The bacteria were permitted to divide once. DNA from some of these bacteria was removed and examined, and it consisted entirely of hybrid DNA with equal quantities of $^{14}\text{N}$ and $^{15}\text{N}$. The rest of the bacteria were kept in the $^{14}\text{N}$ medium and allowed to divide once again. DNA from some of these bacteria was then removed and examined. What is the makeup of this DNA?
Replication and division of nuclei and cells
The arteries nearest the heart have a thick elastic layer in their walls. Which of these statements about this layer are correct?
The circulatory system
The diagram illustrates how pressure in the left side of the heart and the aorta varies during this cardiac cycle, which lasts $0.6\,\text{s}$. Points 1, 2, 3 and 4 show the moments when the atrio-ventricular valves and semi-lunar valves open or close. What is the total duration in one cardiac cycle for which both the atrio-ventricular valves and the semi-lunar valves are closed at the same time?
The heart
The diagram illustrates the role of red blood cells in transporting carbon dioxide. Which row is correct?
Movement into and out of cells
Which parts of the blood are also found in lymph?
The circulatory system
Which piece of evidence supports the cohesion-tension theory of water movement in plants?
Transport mechanisms
Under which mix of environmental conditions are a plant’s stomata most likely to close?
Movement into and out of cells
In general, eukaryotic cells divide far more slowly than prokaryotic cells. What explains this?
Replication and division of nuclei and cells
The diagram illustrates the tissues involved in sucrose transport in a plant. In which location is the concentration of sucrose highest?
Transport mechanisms
What diameter is usually seen in a prokaryote, such as Streptococcus?
Cells as the basic units of living organisms
Which cell structures are found in every prokaryotic cell?
Cells as the basic units of living organisms
The diagram depicts a stage micrometer whose minor divisions are $0.1\,\text{mm}$. It is observed using an eyepiece that has a graticule. The stage micrometer is then changed to a slide containing a plant cell. What is the length of the nucleus?
The microscope in cell studies
In which cell structure are cristae located?
Cells as the basic units of living organisms
Which cell structures include ribosomes?
Cells as the basic units of living organisms