RP : Photosynthesis Flashcards
what is the type of plant weed we use in this experiment called?
Elodea or Cambomba
what is the hypothesis?
the rate of phototsynthesis depends on light intensity
what are the variables?
independent- distance from the light source to the pondweed
dependent- the number of bubbles that are produced every minute
control variables- keeping the same temp by using a transparent screen
length of pondweed by measuring it with a ruler
use same species of pondweed
use the same concentration of sodium hydrogen carbonate powder
what is the method for this experiment?
set up equipment with a lamp at the 0 end of a metre ruler
cut the end of a piece of pondweed and push into measuring cylinder using a glass rod
fill with sodium hydrogen carbonate solution
place cylinder 10cm away from the light source and leave for 2 minutes
start the stopwatch after the 2 minutes and count the number of bubbles produced in a minute
record results in the table and repeat this count 2 more times
repeat this again for lengths 20,30,40 and 50cm away from the light source
what are some risks and hazards in this experiment?
bulb in the lamp can get hot and could burn you so hold the lamp by its stand
the sodium hydrogen carbonate if it gets into your eyes could irritate them so wear goggles
the metre ruler if not careful enough could hit someone so set experiment up far apart from other people
If the bubbles were evolving too fast and you coudn’t keep counting them for a minute what could you do?
count them for 30 seconds and then double the number
if results are repeatable what does that mean?
if the original experimenter repeats the investigation with the same method and equipment obtains the same results
if results are reproducible what does that means?
if the investigation is repeated by another person or by using different techniques or equipment and the same results are obtained
