Figure 17 shows colonies of bacteria growing on an agar plate - Edexcel - GCSE Biology - Question 9 - 2023 - Paper 1

Antibiotics are chemical agents that specifically target bacterial cells and disrupt vital cellular functions, inhibiting the growth and reproduction of bacteria. They can work by interfering with cell wall synthesis, protein synthesis, or DNA replication in bacteria. This selective action minimizes harm to human cells, allowing antibiotics to effectively eliminate the pathogens causing the infection.

Magnification can be calculated using the formula:

$\text{Magnification} = \frac{\text{Size of the drawing}}{\text{Actual size}}$

In this case:

• Size of the drawing = 80 mm
• Actual size = 0.005 mm

So:

$\text{Magnification} = \frac{80}{0.005} = 16000$

Thus, the magnification of the drawing is 16000.

Similarities:

• Both bacterial and plant cells are types of cells that can perform essential functions of life, such as metabolic processes.
• They both contain genetic material (DNA).
• Both have ribosomes for protein synthesis.

Differences:

• Bacterial cells are prokaryotic and do not have a defined nucleus, while plant cells are eukaryotic with a distinct nucleus.
• Plant cells have a rigid cell wall made of cellulose, while bacterial cells have a peptidoglycan layer.
• Plant cells contain chloroplasts for photosynthesis, which bacterial cells typically do not possess.
• Bacterial cells are generally smaller in size compared to plant cells.