Topic 5 Flashcards
(20 cards)
How can glasshouses increase crop yield?
They provide controlled conditions such as temperature, light, and humidity for optimal growth.
How do polythene tunnels help increase crop yield?
They protect crops from pests and weather, and create a warmer environment.
How does increasing carbon dioxide concentration affect crop yield?
It increases the rate of photosynthesis, leading to faster growth and higher yield.
How does increasing temperature affect crop yield?
It speeds up enzyme activity and photosynthesis up to the optimum temperature.
How does the use of fertilisers increase crop yield?
They supply essential mineral ions like nitrates and phosphates to support healthy growth.
Why is pest control important in agriculture?
To prevent pests from reducing crop yield and quality.
What is the advantage of using pesticides?
They are effective and work quickly to kill pests.
What is the disadvantage of using pesticides?
They may harm other organisms, cause resistance, and leave residues.
What is the advantage of using biological control?
It is specific to the pest and avoids chemical pollution.
What is the disadvantage of using biological control?
It may not completely remove the pest and can disrupt ecosystems.
What is the role of yeast in bread production?
Yeast respires anaerobically, producing carbon dioxide that makes the dough rise.
What gas is produced by anaerobic respiration of yeast in bread making?
Carbon dioxide.
What is the role of Lactobacillus in yoghurt production?
It ferments lactose into lactic acid, which thickens the milk and gives yoghurt its taste.
What conditions must be maintained in an industrial fermenter?
Aseptic conditions, nutrients, optimal temperature and pH, oxygenation, and stirring.
Why are aseptic precautions important in a fermenter?
To prevent contamination by unwanted micro-organisms.
Why are nutrients added to a fermenter?
To support the growth and metabolism of micro-organisms.
Why is temperature control important in a fermenter?
To maintain optimum enzyme activity and prevent denaturation.
Why is pH control important in a fermenter?
To ensure enzymes function at their optimum pH.
Why is oxygenation needed in a fermenter?
To support aerobic respiration in aerobic micro-organisms.
Why is stirring used in a fermenter?
To keep conditions uniform and ensure even distribution of nutrients and gases.
