Cell Structure (AQA GCSE Biology: Combined Science)

Both muscle and sperm cells are specialised animal cells.

The nucleus of a muscle cell is different from the nucleus of a sperm cell.

Outline one way in which the nucleus is different between these two cells.

All specialised cells are adapted to carry out their function.  

Describe two adaptations of a sperm cell that enables it to carry out its function. 

Specialised cells develop from unspecialised cells by differentiation when an organism develops.

What happens when a cell differentiates?

Compare the process of differentiation in animals and plants.

Cells can be visualised with a light microscope.

Figure 1 shows some smooth muscle cells from the wall of the small intestine.

Figure 1

All cells contain ribosomes.

Outline the function of ribosomes.

Muscle cells contain many mitochondria, as seen Figure 1.

What is the function of mitochondria?

Suggest why it is possible to visualise mitochondria using a light microscope, but not ribosomes.

Identify which cell from the list below would not contain mitochondria and suggest why this type of cell does not contain this cellular structure.

• Liver cell
• Gamete
• Palisade cell
• Bacterium

Figure 2 shows a bacterial cell and an animal cell as seen in a student’s textbook.

Figure 2

Animal cells store their genetic material in a nucleus, whereas a bacterial cell does not.

Give one other way in which a bacterial cell differs from an animal cell.

The cells in the diagram are drawn to a length of 100 mm in the student’s textbook.

The actual length of the animal cell is 60 micrometers (µm).

Calculate the magnification of the animal cell to 2 significant figures.

Show clearly how you work out your answer.

The nucleus of an animal cell has a diameter of about 6 µm.

Suggest a reason as to why bacteria do not have a nucleus.

Animal and plant cells have some structural features in common.

Name two structures you would find in both an animal cell and a plant cell.

Figure 3 shows a photomicrograph of the surface of a plant root.

Figure 3

Name structure X.

[1 mark]

Calculate the actual length of structure X in Figure 3.

Show your working.

Failure of structure X to develop properly in the cells of a plant root could be catastrophic to a plant.

Suggest an explanation as to why.

Figure 4 below shows a plant cell.

Figure 4

Name each labelled part of the plant cell and give its function.

Identify the cell wall in Figure 4, label it as S and describe its function.

The cell wall of a plant is made from cellulose.

Name one type of cell, other than a plant cell, that has a cell wall made from cellulose.

The cell in Figure 5 below is a salivary gland cell.

Figure 5

Salivary gland cells are adapted to produce salivary amylase, an important enzyme in digestion.

Use the information above and your own knowledge to suggest how salivary gland cells are adapted to their function.

Compare and contrast the structures of eukaryotic and prokaryotic cells.

Include reference to the relative sizes of cellular structures in your answer.

Identify the protein, produced by these cells, that is required for digestion of carbohydrates.

Suggest how the cell in Figure 1 is adapted for its function.

Describe how cell specialisation results in a zygote developing into a baby.

Figure 2

Calculate the size ratio of the bacterial cell compared to the liver cell and mesophyll cell.

Explain the role of differentiation in the development of root hair cells which allows them to carry out their specific function in plants.

Some scientists completed a study to investigate the starch content of roots in a species of grass at four points throughout the year. 

Their results can be seen in Figure 3.

Explain how the starch found in the roots of grass species helps to support growth of the grass.

Calculate the percentage change of stored starch from October to January and suggest a reason for this change.

The micrograph image below shows the organelle responsible for providing energy for cellular processes.

Name the organelle in Figure 4.

The organelle in the image is viewed at a magnification of 20 000 x.

Calculate the actual size of the organelle in Figure 4 and give your answer in mm shown as standard form.

Suggest whether this image was observed through a light microscope or an electron microscope. 

Explain your answer.

Complete Table 1 to show the correct size conversions. Record your answers as ordinary numbers.

Table 1

The mass of bacterial cells was measured in femtograms (fg).

Calculate the mass of bacteria, in grams, immediately after binary fission when the cell growth rate was 0.1 fg s^-1.

Give your answer in standard form.

The electron micrograph shows some cellular structure in a leaf. A student uses their ruler to measure the scale bar, which they find to be 1.5 cm.

Calculate the magnification of the image.