AS & A Level Biology - 9700 Paper 1 2022 Summer Zone 1

A student used a stage micrometer scale to calibrate an eyepiece graticule.
The diagram shows the view of both the stage micrometer scale and the eyepiece graticule seen by the student. The divisions on the stage micrometer scale are 0.1 mm apart.
The student removed the stage micrometer scale and viewed a slide with blood cells on it. The same lenses were used so that the magnification remained unchanged.
The student measured the diameter of one of the white blood cells on the slide using the eyepiece graticule and recorded that it was 8 eyepiece units.
What is the correct diameter of this white blood cell in micrometers?

Four students were asked to match the function with the appearance of some cell structures in an animal cell.
The functions were listed by number.
1 mRNA passes through to the ribosome
2 produces the mitotic spindle during cell division
3 packaging of hydrolytic enzymes that will remain in the cell
The appearances were listed by letter.
V membranes which surround an enclosed inner cavity
W non-membrane-bound, spherical structures
X a double membrane interspersed with pores
Y non-membrane-bound, cylindrical structures
Z membrane-bound sacs, arranged as a flattened stack
Which student correctly matched the numbered function with the appearance of the cell structure?
[Table_1]

Which size range would include most prokaryotic cells?

What is present in a typical prokaryotic cell and a typical eukaryotic cell?

Which statement about viruses is correct?

Samples of glucose, sucrose, and a mixture of glucose and sucrose were divided into two halves M and N.
M was then tested with Benedict’s solution.
N was boiled with dilute hydrochloric acid, neutralised and then tested with Benedict’s solution.
The colour of the solution was compared to colour standards.
Which table identifies the correct colour changes for these samples?
[Table_1]

Which molecules contain 1,4-glycosidic bonds? (amylose, cellulose, glycogen)

The diagram shows three triglycerides, X, Y and Z. Which row is correct for these triglycerides? [Table_1]

Some foods contain hydrogenated vegetable fats. These are unsaturated fats that have been converted to saturated fats.
Which property of the fats will have changed?

A polypeptide contains a specific number of amino acids, $n$.
How many peptide bonds are present in this polypeptide?

Which statement is correct?

A student used colorimetry to monitor the hydrolysis of a protein by a protease enzyme. The student used biuret solution to determine the concentration of protein in the hydrolysis reaction. The student produced a calibration curve using known concentrations of protein. Which diagram shows the calibration curve?

A student completed an experiment to measure how increasing concentrations of substrate affects the rate of an enzyme-controlled reaction.
The student then repeated the experiment after adding a fixed quantity of a reversible competitive inhibitor.
Which row describes the effect of a reversible competitive inhibitor on enzyme activity? [Table_1]

The diagram shows a liposome. Liposomes can be used to move therapeutic drugs into cells of the body to treat conditions such as cancer. Which row shows the property of a drug that could be transported in the sections of the liposome labelled 1 and 2? [Table_1]

Some processes occurring in cells are listed.
1. endocytosis of water into cells
2. exocytosis of enzymes from cells
3. facilitated diffusion of glucose into red blood cells
4. phagocytosis of dead cells by macrophages
Which processes use ATP?

The graph shows changes in the concentration of a solute inside a cell.

What explains this change in concentration?
1. diffusion
2. endocytosis
3. exocytosis
4. osmosis

The indicator cresol red, changes from red to yellow when put into acid.
Four blocks of agar containing cresol red were cut to different sizes measured in millimetres. The blocks were submerged in acid. All other variables were kept constant. The time taken for each of the blocks to completely turn yellow was recorded.
Which of the four blocks became completely yellow most quickly?

Which processes require mitosis?
1. the cloning of T-lymphocytes
2. the repair of cell structures by protein synthesis
3. the growth of multicellular organisms from a single cell
4. the reproduction of a unicellular eukaryote

Which events listed are part of the cell cycle?
1. interphase
2. prophase
3. cytokinesis

Telomerase is an enzyme that adds nucleotides to telomeres.
Which statement about telomerase is correct?

The photomicrograph shows cells at different stages of mitosis.



A student wrote four statements about the photomicrograph.
1. Cell P shows anaphase.
2. Spindle formation is occurring in cell Q.
3. The amount of DNA in cell R is the same as in cell T.
4. The correct order for the stages is $S \rightarrow R \rightarrow T \rightarrow P \rightarrow Q$.

Which statements are correct?

Bacterial cells with DNA containing only the ‘heavy’ isotope of nitrogen ($^{15} ext{N}$) are allowed to reproduce for three generations in a culture medium containing the normal isotope of nitrogen ($^{14} ext{N}$).
Which percentage of the DNA molecules produced contain strands with the heavy isotope of nitrogen?
[Table_1]

A bacterial circular DNA molecule is 2600150 base pairs long. 26\% of the bases are adenine. How many cytosine bases would be in the DNA molecule?

Which statement relating to the structure of DNA is correct?

A student sketched a diagram to represent the process of transcription.
Which part of their diagram shows the non-transcribed strand?

Which row is correct for the movement of water in a root?
[Table_1]

The table contains some information about uptake and movement of water and of mineral ions in plants.

[Table_1]

Using the information provided, which factors will affect the uptake and movement of water or of mineral ions in plants?
1. humidity
2. surface area of root hair cell
3. oxygen concentration
4. temperature

Which changes to the water potential and the volume of solution in the phloem sieve tube occur when sucrose is moved from a photosynthesising leaf into the phloem sieve tube? [Table_1]

A student wrote the following statements about a possible mechanism for loading sucrose from a source.
1. When energy is released from ATP, the released energy is used to move sucrose through a co-transporter protein in the companion cell membrane.
2. As sucrose is moved into a companion cell the pH in the cell wall of the companion cell decreases.
3. Proton pumps in the cell membrane of a companion cell move sucrose into the phloem sieve tube element.
Which statements are correct?

The diagram shows a transverse section through an artery.
Which tissues are present in layer X?

What is systolic blood pressure?

The diagram shows pressure changes in the left side of the heart and aorta over time. The length of this cardiac cycle is 0.6 s. Points 1, 2, 3 and 4 indicate when atrioventricular valves and semilunar valves either open or close.
What is the total time during one cardiac cycle that the atrioventricular valves and the semilunar valves are both closed at the same time?

Which reactions take place in the capillaries surrounding an alveolus?
1. carbon dioxide + water → carbonic acid
2. carbon dioxide + haemoglobin → carbaminohaemoglobin
3. haemoglobinic acid → haemoglobin + hydrogen ions
4. hydrogencarbonate ions + hydrogen ions → carbonic acid → carbon dioxide + water

Which statement explains the importance of the chloride shift in red blood cells (RBC)?

The photomicrographs show a cross-section through the lining of part of the respiratory system.
Which statements about the photomicrographs are correct?
1. Goblet cells are visible between squamous epithelium cells.
2. Smooth muscle is visible.
3. The section cannot be from a bronchiole as cartilage is visible.

The surface tension of the layer of liquid lining the alveoli tends to pull the walls inwards so alveoli could collapse.
Which statements could explain how this is prevented?
1. Alveolar fluid is moved around by cilia.
2. Elastic fibres keep the alveoli open.
3. Epithelial cells secrete a chemical that reduces the cohesion in water.

What will reduce the rate at which bacteria become resistant to antibiotics?
1. prescribing two antibiotics with different modes of action
2. prescribing different antibiotics for the same bacterium
3. finishing a prescribed course of antibiotics

T-lymphocytes have a protein, PD-1, on their surface. Some cancer cells have a receptor molecule on their surface which binds with PD-1, inactivating the T-lymphocyte.
A monoclonal antibody, lambrolizumab, has been produced against this receptor.
Trials showed that in 54 of 135 people with advanced skin cancer who were given lambrolizumab the tumours more than halved in volume. In six of the 57 people who were given the highest dose the tumours disappeared.
What may be correctly concluded from this information?

A person's blood group is determined by antigens present on the red blood cells.
The table shows the antigens and antibodies in the blood of people with different blood groups.

[Table_1]

During a blood transfusion, it is essential that the person receiving the blood does not have antibodies to the donor's blood.
Which blood groups can be given to a person with blood group AB?

Which types of cell are stimulated to divide by the cytokines produced by T-helper cells?