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Figure 10 shows colonies of bacteria growing on an agar plate - Edexcel - GCSE Biology Combined Science - Question 6 - 2023 - Paper 1
Question 6
Figure 10 shows colonies of bacteria growing on an agar plate. Each colony starts as one bacterium. Every time bacteria reproduce, the number of bacteria in each c... show full transcript
Worked Solution & Example Answer:Figure 10 shows colonies of bacteria growing on an agar plate - Edexcel - GCSE Biology Combined Science - Question 6 - 2023 - Paper 1
Step 1
Calculate the number of bacteria in a colony after five hours
Answer
To calculate the number of bacteria after five hours, we need to determine how many 30-minute intervals are in five hours. There are 10 intervals in a five-hour period (300 minutes / 30 minutes).
The formula for the number of bacteria is:
y = 2^n
where n is the number of divisions. Thus:
y = 2^{10} = 1024.
Therefore, there are 1024 bacteria in the colony after five hours.
Step 2
Step 3
Explain why antibiotics can be used to treat bacterial infections
Answer
Antibiotics are effective against bacterial infections because they inhibit processes that occur in bacteria. They can disrupt cell walls, stop protein synthesis, or interfere with DNA replication. Importantly, antibiotics do not damage human cells, as they specifically target bacterial cells.
Step 4
Step 5
Describe the similarities and differences of a bacterial cell and a plant cell
Answer
Similarities:
- Both bacterial cells and plant cells have a cell membrane.
- Both have cytoplasm and ribosomes.
- Both types of cells contain DNA.
Differences:
- Bacterial cells have chromosomal DNA, while plant cells usually have linear DNA organized within a nucleus.
- Bacterial cells are generally smaller and prokaryotic, whereas plant cells are eukaryotic and larger.
- Bacteria may have flagella for movement, while plant cells do not.