AS & A Level Biology - 9700 Paper 1 2018 Summer Zone 2

Some features of cells are listed.
1. cell wall
2. cell surface membrane
3. ribosomes
Which features can be found in plant cells and in prokaryotic cells?

Which of these statements about light microscopy are correct?
1. The greater the resolution of a light microscope, the greater the detail that can be seen.
2. The greater the magnification of a light microscope, the greater the detail that can be seen.
3. Increasing the magnification of a light microscope up to its limit of resolution allows more detail to be seen.
4. The shorter the wavelength of light used in a light microscope, the greater the detail that can be seen.

Which type of cell contains the highest proportion of cell structures bound by a single membrane?

The table shows a variety of structures which may be found in cells.
Which row shows structures that could be found in the root cells of a plant?
[Table_1]

Which of these cell structures are present in \textit{Plasmodium}?

A student was asked to estimate the concentration of glucose in a solution using the Benedict's test. The student was provided with a 1.0 mol dm^-3 glucose solution and was told to make a 0.6 mol dm^-3 solution by proportional dilution.
Which row shows the correct volumes of both 1.0 mol dm^-3 glucose solution and distilled water needed to make the 0.6 mol dm^-3 solution? [Table_1]

The diagram shows part of a carbohydrate molecule formed by glucose. What is the name of the molecule?

The diagram shows the relationship between some biological molecules.

Which row is correct?

Which diagram shows the reaction that occurs to join two of the monomers that form cellulose?

Which molecules contain C=O bonds?
1 amino acids
2 fatty acids
3 glycerol

Which row describes a collagen molecule?
[Table_1]

A student investigated the hydrolysis of the lipid in high-fat milk, using the enzyme lipase.
• 1 cm³ of enzyme solution was added to 10 cm³ of high-fat milk.
• The temperature was kept constant.
• The pH of the reaction mixture was recorded at time 0 minutes and every minute for 20 minutes.
Which statements could be supported by the results of the investigation?
1. Less product is made as time proceeds because the substrate is decreasing.
2. The pH of the reaction mixture changes more rapidly in the first few minutes and then changes less rapidly.
3. The product gradually causes more lipase molecules to denature.

A student carried out an investigation into the effect of temperature on the rate of an enzyme-catalysed reaction. At each temperature, the substrate concentration was measured after 10 minutes. All the other variables were kept constant. Which graph shows the effect of increasing temperature on the substrate concentration after 10 minutes?

The graph shows how the rate of an enzyme-catalysed reaction depends on the concentration of substrate.
What is the Michaelis-Menten constant \(K_m\) for this enzyme under these conditions?

The formula shows how the rate of diffusion across a cell surface membrane can be calculated.

$$\frac{\text{surface area} \times \text{difference in concentration}}{\text{thickness of membrane}}$$

Which row shows how the fastest rate of diffusion can be achieved?

[Table_1]

The diagram shows part of the cell surface membrane of an active animal cell.

Which statements correctly describe the net movement of molecules across this membrane?
1. Oxygen diffuses through molecules M from X to Y.
2. Carbon dioxide diffuses through molecules M from X to Y.
3. Water moves from Y to X through molecule L.

Some epidermal cells from a well-watered plant are placed in three solutions which have different water potentials.
Which row correctly shows the state of the plant cells in each of the solutions?
[Table_1]

One of the chromosomes in a nucleus has a telomere which contains many repeats of the base sequence TTAGGG.
This chromosome was extracted from four different cells and the total number of bases in the telomere was determined.
Which total number of bases was found in the cell that had undergone the most mitotic divisions?

The chromosome content of each daughter cell must be identical to that of the mother cell for successful cell replacement when repairing tissues. Which stages of mitosis make sure that each daughter cell receives one chromatid from each chromatid pair?

Which of these statements about cytokinesis is always true?
1. Cell structures replicate.
2. Cell structures are shared between two cells.
3. Nuclear envelope reforms.

Which statement is correct about the number of telomeres present in prophase of a human body cell?

Which statement explains why DNA replication is described as semi-conservative?

A section of a DNA molecule has the coding sequence: AGGCAATGGC.
Which statements are correct?
1. This coding sequence contains 3 pyrimidines.
2. The double-stranded DNA of this section contains 26 hydrogen bonds between complementary bases.
3. The double-stranded DNA of this section has 20 sugar-phosphate bonds.

XNA is a laboratory-made nucleic acid made of nucleotides in which one component has been replaced by chemical X. The chemical X is not found in nature. The part of the molecule responsible for coding is not changed.
Which organic component of a DNA or RNA nucleotide has been replaced by X?

Which statements about tRNA are correct?
1 Hydrogen bonds between bases temporarily hold tRNA against mRNA.
2 The base sequences in the tRNA molecules are the same as the base sequences in the mRNA that is being translated.
3 The specificity of the tRNA molecule for glycine and the specificity of the enzyme that loads glycine are both necessary for correct loading.

What is the role of ATP in a companion cell when sucrose is loaded into a sieve tube element?

A potometer was used to measure the transpiration rate of a leafy shoot. What could be the correct units?

Which combination of features is characteristic of a phloem sieve tube element as it is loaded from a source?

[Table_1]

The diagrams show transverse sections of parts of a plant.
Which structures, labelled 1 to 4, transport water and sucrose? [Table_1]

Which statement explains why the ventricles contract after the atria?

If the left atrioventricular valve in the heart does not close completely it results in blood flowing back into the atrium during ventricular systole.
What would be the immediate effect of this back flow?

The graph shows two oxygen dissociation curves, one for a tissue at rest and one for the same tissue during exercise.
What factors have caused the difference in the position of the dissociation curve during exercise compared with the dissociation curve for the tissue at rest?

Which of these statements about the formation of haemoglobinic acid are correct?
1. It can only occur with the dissociation of oxygen from haemoglobin.
2. It removes excess hydrogen ions preventing blood becoming too acidic.
3. It is linked to the action of carbonic anhydrase.

Which of these structures contain cartilage and cilia?
1. bronchi
2. bronchioles
3. trachea

What correctly describes the effect of carcinogens on lung tissue that causes a tumour to develop?

Which row identifies both the type of pathogen that causes cholera and the way in which cholera is transmitted from person to person? [Table_1]

Why do people with HIV/AIDS have a higher occurrence of malaria than people without HIV/AIDS?

How many variable regions are there on a typical Y-shaped antibody molecule?

Where are antigens found?
[Table_1]

When an organ is transplanted from one person to another, rejection of the non-self organ must be avoided. At the same time, the immune system of the recipient must be maintained to prevent death from infections.
What prevents rejection of the transplanted organ?