Required Practicals Paper Two Flashcards
The diagram shows some equipment set up by a student to measure the effect of light intensity on the rate of photosynthesis. What is the independent variable?
the distance of the lamp from the plant
Suggest why LED lamps are more useful for photosynthesis experiments than filament bulbs
They produce less heat
Which dependent variable is more likely to give a precise measurement of gas produced by water plants.
measuring the volume of gas by collecting bubbles
What is the gas in the bubbles produced by the water plant?
Oxygen
Why is temperature an important control variable?
it affects the rate of photosynthesis
In which order would you change the magnification of an image using the objective lenses?
low magnification to high magnification
In which order do you adjust the focus of the image?
adjust the coarse focus and then the fine focus
What is the magnification of a microscope with a x10 eyepiece lens and a x40 objective lens?
400
What is sometimes used so that you can see certain structures in cells more clearly?
a coloured stain
Which type of microscope has the highest magnification and resolution?
electron microscope
True or False? The number of bubbles decreases as the distance from the light source increases.
True
A student decides to repeat her investigation. Which reason explains why she should use a piece of pondweed with the same number of leaves?
a plant with more leaves will carry out more photosynthesis
What is the specimen?
The object you will look at
In the photosynthesis required practical what is the independent variable?
Light intensity - the distance of the lamp from the pondweed
In the photosynthesis required practical what is the dependent variable?
The rate of photosynthesis - the number of bubbles per minute
