sb6 Flashcards
How would you describe photosynthetic organisms?
The main producers of food and biomass
What is photosynthesis?
An endothermic reaction that uses light energy to react carbon dioxide and water to produce glucose and oxygen
How does light intensity affect the rate of photosynthesis?
the higher the light intensity, the faster the rate of photosynthesis
How does the concentration of carbon dioxide affect the rate of photosynthesis?
As the concentration of carbon dioxide increases, so does the rate of photosynthesis
How does temperature affect the rate of photosynthesis?
- increasing temperature also increases rate of photosynthesis
- this will continue until a point where enzymes start to denature and the rate of reaction decreases/stops
What is a limiting factor?
An environmental condition such as light intensity which in low levels restricts any increase in the rate of reaction
What is the independent variable in the cb6 core practical
light intensity and the distance from lamp
What is the dependant variable in the cb6 core practical?
The change in pH
What is the control variable for the cb6 core practical?
- temperature (as it also affects rate of photosynthesis)
- volume of indicator
- number of algal balls
- the lamp
How can you increase reliability of results?
- repeating experiments
- calculating a mean
- identifying anomalies
What is the control experiment for the cb6 core practical?
The same experiment but with the tube covered in foil
Why is light intensity directly proportional to the rate of photosynthesis?
The greater the light intensity, the more light energy hit chloroplasts, where photosynthesis occurs
What is the inverse square law?
Light intensity = 1/distance^2
What are some adaptations of xylem cells?
- Lignin on cells
—> withstands high water pressure
What are some adaptations of phloem cells?
- A lot of mitochondria from companion cells
—> for energy to transport sucrose