1. Which organism commonly produces carbon dioxide in bread making?
- A red blood cell
- A virus
- Yeast
Check the answer and reasoning
Yeast
Yeast metabolises sugars and releases carbon dioxide that expands the dough.
Biology / IGCSE
Biotechnology uses organisms or biological processes to make useful products.
Biotechnology uses organisms or biological processes to make useful products. Yeast fermentation can produce ethanol and carbon dioxide; controlled fermenters regulate factors such as temperature, nutrients and contamination.
Genetic modification changes genetic material, for example by introducing a gene enabling a production cell to make a useful protein. The outcome depends on expression and biological context. Product safety, ecosystem effects and access need case-specific evidence, not assumptions that all modifications have identical risks.
A supplied fermenter dataset shows 12 g product from 3 dm³ culture. Find product per dm³.
Divide mass by culture volume: 12/3=4 g per dm³.
Using the worked example as supplied data, predict the effect of changing one condition. Draw a labelled model, record your reasoning and identify a variable that would need controlling. No human, animal or microbial experiment is required.
Related simplified PhET model. Explain what it represents and what the living system does differently.
Yeast
Yeast metabolises sugars and releases carbon dioxide that expands the dough.
4 g/dm³
Divide mass by culture volume: 12/3=4 g per dm³.
No
Traditional fermentation can use unmodified organisms; genetic modification specifically changes genetic material.