AS & A Level Biology - 9700 Paper 1 2024 Summer Zone 1

The diagram shows a stage micrometer scale viewed with an eyepiece graticule, using a magnification of ×200.
Using the same magnification, a chloroplast is measured as 4 eyepiece graticule divisions long.
How long is the chloroplast?

Which range of cell diameters is typical for prokaryotic cells?

The diagram shows a typical animal cell.

Where would nucleic acids be found?

Which structure is found in a typical bacterial cell?

What is the maximum number of hydrogen bonds that can form between a single water molecule and other water molecules?

The diagrams show the structure of four amino acids in aqueous solution. Which two structures have an overall charge?

The table shows the number of carbon atoms and the number of carbon–carbon double bonds in molecules of three triglycerides and the fatty acids they contain.
The information is shown in the format 'number of carbon atoms : number of carbon–carbon double bonds'.
[Table_1]
Which description matches fatty acid 2 of the 56:4 triglyceride, identified in the table as X?

Collagen molecules are made up of three polypeptide chains interacting together. The individual polypeptide chains consist of a regular pattern of amino acids. Almost every third amino acid is glycine. Which protein structures of collagen are described?

The masses of the parts of haemoglobin are shown in the table.
[Table_1]
There are 1000 Da in 1 kDa.
What is the mass of a haemoglobin molecule in kDa?

What is the correct order of locations in the cell for the production of an extracellular enzyme?

The graph shows the trend from an enzyme-catalysed reaction.
Which labels are correct for the x-axis and y-axis?
[Table_1]

Which statements about the Michaelis–Menten constant ($K_m$) are correct?
1. The higher the $K_m$, the higher the enzyme affinity for the substrate.
2. $K_m$ is a measure of the degree of enzyme affinity for the substrate.
3. $K_m$ is defined as the substrate concentration at which the enzyme functions at half its maximum rate.

The diagram shows how nicotine is transported from the blood plasma into a cell using a type of cotransporter mechanism.



In the phloem tissue, there is a cotransporter mechanism that moves sucrose into the cytoplasm of a companion cell.
Which statement correctly describes a similarity between the cotransport of nicotine and the cotransport of sucrose?

The diagram shows a simple metabolic pathway.

W \rightarrow X \rightarrow Y \rightarrow Z

The letters W, X, Y and Z represent four different substances. At each step in the diagram the substrate undergoes a chemical reaction catalysed by an enzyme. The reaction produces the next substance in the pathway.

Which statements correctly describe the enzymes taking part in this metabolic pathway?

1. They are all globular proteins.
2. They all have the same tertiary structure.
3. They all contain hydrogen atoms in their structure.

A student observed the effect of two different concentrations of salt solution on blood cells.

The student added each concentration of salt solution to one of two microscope slides, and then a small drop of fresh blood was added.

Each slide was viewed using the high power lens of a microscope and the student's observations were recorded.

slide 1 No red blood cells were visible.

slide 2 The red blood cells were visible but looked slightly crinkled.

Which row correctly explains the results obtained?

[Table_1]
Key: \( \Psi = \text{water potential} \)

Which statement correctly describes facilitated diffusion?

Which row is correct for stem cells? [Table_1]

Eukaryotic organisms grow and increase in size as a result of cell division. The diagram shows some stages of mitosis with one stage missing, labelled X.



What happens in stage X?

The graphs show various distance measurements taken from the start of metaphase of mitosis. The graphs are to scale when compared to one another.

Which row correctly identifies the distance measurement for each graph?

Which row is correct for the start of anaphase of mitosis? [Table_1]

The diagrams show the chemical structure of four bases.

Which diagrams show thymine and cytosine?

The diagram shows the nucleotide sequence of a small section of the transcribed strand of a gene.

CGG GCC CCG CGG

The table shows the amino acids coded for by 10 mRNA codons.

[Table_1]
What is the sequence of the four amino acids in the polypeptide translated from this small section of a gene?

What does the process of translation require?

The electron micrograph shows a longitudinal section of part of the stem of a plant.



What is the name of the structure labelled X?

Which substance makes xylem vessel walls impermeable to water?

The following tissues carry an electrical impulse during the cardiac cycle.

1. atrioventricular node
2. muscle wall of atria
3. Purkyne tissue
4. sinoatrial node

In which order does the electrical impulse travel during the cardiac cycle?

The graph shows changes in the volume of the ventricles during a single cardiac cycle.



Which row is correct for the atrioventricular valve at P and for the semilunar valve at R?

The graph shows how changes in oxygen concentration affect the percentage oxygen saturation of human haemoglobin and cat haemoglobin under normal physiological conditions. The partial pressure of carbon dioxide was kept constant at 5.0 kPa and the temperature was kept constant at 37 °C.

Which conclusion is supported by the graph?

Which statement is correct about how oxygen combines with haemoglobin?

How are alveoli adapted to their function?

The diagram shows oxygen diffusing from the space inside an alveolus into the blood through the gaseous exchange surface.



What would increase the rate of diffusion of oxygen from the alveolus to the blood?

Which tissues are present in a bronchus?
[Table_1]

Steep concentration gradients must be maintained for efficient gaseous exchange to occur in the human lungs.
Which row correctly describes how steep concentration gradients can be maintained?
[Table_1]

A scientist investigated the effect of an antibiotic on the treatment of cholera.
320 people with cholera were divided into two groups. One group was treated with the antibiotic while the other group was not given the antibiotic. Both groups were given fluids containing sugars and mineral salts (oral rehydration therapy).
The scientist recorded the number of days that each person had diarrhoea.
The table shows the results.

[Table_1]

What is the percentage decrease in the mean time that a person had diarrhoea when they were treated with the antibiotic?

How does the antibiotic penicillin affect the metabolism of a bacterial cell?

Scientists studied the multidrug-resistant bacterial infections in children caused by one type of bacteria between 2007 and 2015. The percentage of multidrug-resistant infections rose from 0.2% to 1.5%.
What was the percentage increase in multidrug-resistant infections between 2007 and 2015?

Whooping cough is a highly infectious disease of the gas exchange system, caused by the bacterium Bordetella pertussis.
Which method provides protection to infants against whooping cough and reduces the chance of developing this disease later?

The electron micrograph shows a type of blood cell.
What can be concluded from the electron micrograph?

Why is mitosis important in the immune response?

What is fused with a B-lymphocyte to form a hybridoma cell in monoclonal antibody production?