maths/graphs in biology

Question 1

how do you calculate percentage error?

Answer 1

error/actual reading x 100

Question 2

how do you calculate rate of reaction (in enzyme experiments)?

Answer 2

1/time

Question 3

how do you calculate rate of reaction from a reaction progress graph?

Answer 3

draw a tangent to the curve and draw a line of best fit

Question 4

what should you do if the data given only shows the time completed to complete the reaction (specifically in enzyme experiments)?

Answer 4

calculate rate of reaction using 1/time

Question 5

how do you calculate rate of reaction from a reaction progress graph (graph which shows mass of products made/ mass of reactants used up against time?)

Answer 5

draw a tangent to the curve and calculate gradient

Question 6

how would you answer a question which asks to evaluate the effectiveness of a certain treatment? (5)

Answer 6

1) explicitly state if it is ineffective/effective
2) explicitly give a reason why and be specific with data
e.g effective bc levels of x reduce after 4 months
3) link data to disease
e.g ineffective bc symptoms will still occur for 2 months
4) state if data remains stable/ increases/ decreases and at what point
5) state if there are reasons for unreliability e.g
only shows results for a short period of time
unknown side effects
no control group/ only one person

Question 7

how do you calculate log(10) of antibodies when a question gives you data with a wide range of values?

Answer 7

log(whatever the number is)

Question 8

how do you work backwards when the question gives you
log10+6.22

Answer 8

press shift and put in the number
e.g
log10=6.22
10^6.22

Question 9

how to answer a question that gives you a scale and asks you to calculate the minimum distance of something? (3)

Answer 9

1) measure scale with ruler in
2) measure width of object asked to measure in image
3) divide step 2 by step 1 and multiply by number on the scale

Question 10

what is the surface area of a sphere?

Answer 10

4 pi r2

Question 11

what is the volume of a sphere?

Answer 11

4/3 pi r3

Question 12

outline how you would answer a question which asks you to calculate the number of stomata per mm2 of the leaf surface and shows an image of four stomata with a scale of 0.1mm

Answer 12

1) measure the scale in cm
2) measure the length in cm and multiply this by step 1
3) multiply step 2 by the scale (0.1mm)- this gives the length
4) measure the width and repeat the above steps
5) multiply length by width to calculate area in mm2
6) count the stomata and put the answer to step 5 = to this
7) multiply area to get 1mm2 and do the same to the number of stomata

Question 13

when working out SA:V, what should you do on a calculator

Answer 13

divide by fraction