Using Biology Flashcards
How can awareness of limiting factors and how they affect the rate of photosynthesis be used by farmers?
To improve crop yields
When can’t a farmer control limiting factors?
If their crops are being grown outside
How does growing plants in an enclosed environment affect farmers and why?
It increases their crop yields as they can control the climate inside
Examples of enclosed environments for crops to grow
Glasshouses, polythene tunnels
Whatis the purpose of manipulating condiitons in a glasshouse?
To increase the rate of photosynthesis
How can conditions be manipulated in a glasshouse?
Artificial heating, artificial lighting, increasing carbon dioxide content, regular watering
How does artificial heating in glasshouses work?
Enzymes controlling photosynthesis can work faster at slightly higher temperatures
Where in the world can artificial heating be used?
In temperate countries such as the UK
How is artificial lighting useful in glasshouses?
It means that plants can synthesise for longer
How is increasing carbon dioxide content of the air inside a glasshouse useful?
It means that plants can photosynthesise quicker
What do farmers need to financially balance when using glasshouses?
The extra cost of providing manipulating conditions against increased income
Can tropical countries use glasshouses to control other conditions?
Yes as long as they are well ventilated to release hot air and avoid temperatures rising too high
What happens if temperatures rise too high in a glasshouse?
The enzymes controlling the photosynthesis reaction may denature
What are polythene tunnels (polytunnels)?
Large plastic tunnels that cover crops
What do polytunnels do?
Protects crops grown outside from the effects of weather, including excessive wind, rain and extreme temperatures
What can polytunnels do to the temperature inside the tunnel?
Increase it slightly
What can polytunnels prevent?
The entry of pests that can damage plants or diseases that can kill plants
What is a limiting factor?
A factor that is the lowest at the time that limits something from occurring to its full potential
What are the three main factors that limit the rate of photosynthesis?
Temperature, light intensity, carbon dioxide concentration
How and why does temperature affect the rate of photosynthesis?
The rate of photosynthesis increases as the reaction is controlled by enzymes
What happens to the rate of photosynthesis if the temperature gets too high and why?
It will decrease as the enzymes would begin to denature
How does light intensity affect the rate of photosynthesis?
The more light a plant receives, the higher the rate of photosynthesis
How does carbon dioxide affect the rate of photosynthesis?
The more carbon dioxide that is present, the faster the reaction can occur