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Name the three general shapes of bacterial cells - Leaving Cert Biology - Question 15 - 2015
Question 15
Name the three general shapes of bacterial cells. What is meant by the term pathogen? What is the difference between ‘asepsis’ and ‘sterility’? Give one way in wh... show full transcript
Worked Solution & Example Answer:Name the three general shapes of bacterial cells - Leaving Cert Biology - Question 15 - 2015
Step 1
Name the stages B, C and D.
Answer
Stage B represents the logarithmic (log) phase of bacterial growth, where bacteria multiply rapidly. Stage C indicates the stationary phase, where the growth rate stabilizes as resources become limited. Stage D is the decline (or death) phase, where bacteria start to die off due to lack of nutrients and accumulation of waste.
Step 2
Explain what is happening during stage C.
Answer
During stage C, bacteria enter the stationary phase. This phase is characterized by a balance between cell division and cell death. Factors such as limited nutrients, reduced availability of resources, and waste accumulation contribute to this stabilization. The growth rate equals the death rate, resulting in a relatively constant population size.
Step 3
Distinguish between batch processing and continuous flow in food processing.
Answer
Batch processing involves adding a fixed amount of nutrients at the beginning of the process and typically emptying the bioreactor at the end of production. During this time, all growth stages occur. In contrast, continuous flow processing entails nutrients being continuously fed into the bioreactor, or the product being removed continuously, allowing for sustained production and maintaining a constant population, typically around stage B or C.