cpac 1 -daphnia
Give two reasons why daphnia are used to investigate heart rate?
- They are transparent so it is easy to see their heart beating
- They have a less complex nervous system so they will not feel any pain
- note- daphnia reproduce asexually so will not affect population of daphnia
cpac 1 - daphnia
state the control used in Daphnia CPAC
- solution that does not contain caffeine
- to determine resting HR of daphnia
c1
how do you analyse results for daphnia cpac
calculate mean hr of daphnia for each concentration and standard deviation - if no overlap in error bars then result is significant
What is a control
Control is used for comparison to ensure valid results
state the control variables in daphnia and many other experiments
Usually two from:
* age/size/species of daphnia
* temperature/ph/ acclimatisation time
c17 - investigating breathing
Describe how to measure vital capacity
- difference between peak and trough in one cycle
equation for respiratory minute ventilation
tidal volume x rate of breathing
why is soda lime used for in cpac 17
**to absorb co2 **in order to ensure only volume of oxygen is measured
what does spirometer measure?
change in volume of gases in breathing
how can oxygen consumption per minute be measured using a spirometer trace
- difference in volume of one peak or trough compared to subsequent peak
- divide by time between two peaks or troughs and multiply by 60
why is it important that co2 is removed from system in cpac 17
so changes in volume are only due to oxygen being used up
