what is the use of standard deviation
Measure range of values around the mean
what do overlapping standard deviation bars mean
the difference between two values is not significant
what is the use of the students t test
To find the difference between two means and whether it is significant
how to calculate degrees of freedom for the students t test
2n-2
in the students t test, when to accept the null hypothesis
t value is less than the critical value
means difference is due to chance
in the students t test, when to reject the null hypothesis
t value is more than the critical value
means difference is not due to chance
what is the use of Spearman’s
Rank correlation
Used to see the strength of the correlation (association) between two sets of continuous data
how to calculate degrees of freedom for Spearman’s
Rank correlation
n-2
in Spearman’s Rank correlation, when to reject the null hypothesis
if your calculated number is the same or higher than critical value then your correlation is significant and you would reject the null hypothesis
in Spearman’s Rank correlation, what will the result always be between
1 and minus 1
what is the use of the Chi- Squared test
Used to compare observed results with theoretical expected frequencies. The higher the X2 value the greater difference.
how to calculate degrees of freedom for the chi squared test
(n‐1)
when to reject the null hypothesis for the Chi Squared test
Greater value than critical value
how does caffeine increase heart rate in humans
by increasing release of excitatory neurotransmitters
why are daphnia used to investigate the effect of caffeine on heart rate
they have a translucent body through which the heartbeat can be observed
when investigating the effect of caffeine on heart rate in Daphnia, why is a coverslip not placed over the daphnia
to allow daphnia to access oxygen to aerobically respire
what happens when DCPIP is in the presence of vitamin C
reduced
decolourised from blue to colourless
what can change the permeability of a phospholipid bilayer
temperature and concentration of solvents, like ethanol
how to measure the permeability of a membrane
amount of beta lain pigment leaked from beetroot cells into an aqueous solution using a colorimeter
what happens to beetroot cells when the cell surface membrane has a higher permeability
more beta lain pigment leaks out of cells
how to cut beetroot into identical cylinders
cork borer
in the beetroot experiment, what does a higher absorbance indicate
higher pigment conc
more permeable membrane
impact of high temp on permeability of cell surface membrane
permeability increases
proteins in the membrane denature
heat damages the bonds in their tertiary structure
creates gaps in the membrane easier for molecules to pass through it
impact of low temp on permeability of cell surface membrane
permeability decreases
phospholipids have little energy
packed closely together to make the membrane rigid
restricts molecules from crossing the membrane
