module 1 Flashcards
what is the formula for magnification
I/AM
where I is image size
A is actual size
and M is magnification
define Q10
the factor by which the rate of reaction increases for every 10 degrees rise in temperature (celcius or kelvin - units must match)
there are no units
10/(T2-T1)
Q10 = R2
R1
were R is rate and T is temperature
usually between 2-3
how do you calculate the SA and V of a sphere
SA is 4pi r^2
V is 4/3 pi r^3
what is the rf value
Used in chromatography to indicate how polar a molecule is.
it is the distance moved by compound/distance moved by solvent
we can compare the Rf value to a known table of values in order to identify the unknown
give the equation for the cardiac output (volume of blood the heart pumps per minute)
the stroke volume x heart rate
stroke volume is the volume of blood pumped out of the left ventricle with each systolic contraction
2 x pi x r tells us …
circumference of a circle
pi r^2 tells us …
area of a circle
how do you calculate efficiency
biomass transferred/ biomass intake x100
what is the RQ value
the respiratory quotient
carbon dioxide exhaled / oxygen inhaled
how do you calculate biodiversity
number of polymorphic gene loci/ total number of loci
how do you calculate percentage error
what steps can be take to reduce this value
number of readings x uncertainty of the scale / reading x100
where the uncertainty of the scale is half of the smallest interval
increase the resolution (use more precise equipment with smaller intervals)
use a greater amount of something
what are the 2 different types of error in results that you can get
random error - this is when the results are not likely to be reliable as the don’t have high resolution (they are not close together/ round the mean)
the best way to deal with this is to reduce the effects by completing more readings so it has a higher repeatability and reduces the chance of anomalies.
systematic error - this is usually due to equipment not working and can lead to results repeatedly occurring in predictable ways. this can be reduced by recalibrating the equipment
when calculating a mean, how many decimal places should you write your answer to
one decimal place greater then the raw score. if you do anymore you will lose the mark for inappropraite use of dp
outline when the most appropriate time is to plot a …
1. scatter graph
2. histogram
3. bar chart
4. line graph
also list some key details to consider for each graph
- when you have two dependent variables (measured) ie height and weight. involves using a spearman’s rank in order to test whether there is a correlation between them
- represent continuous data when there is no independent or dependent variable ie women’s height in inches . the bars should touch.
- discontinuous data is presented on a bar chart where the lines do not touch. ie the percent of populations blood types
- continuous data independent variable is on the x axis and the dependent variable is on the y axis.
what does the standard deviation tell you
it tells you have spread out the data is around the mean
a small value indicates that the values are close to the mean so your results are precise and has high repeatability
if SD is high then the results have low repeatability, the values are not around the mean so results are less precise
it can be shown on a graph using error bars. the greater the overlap in error bars between two sets of data, the less confident you can be in the overall trend - as many of the same values are present in both data sets.
a small overlap is more confidence in your results as fewer datasets are being sharing results values.
