maths

Question 1

what is uncertainty?

Answer 1

amount of error in a measurement
- due to limit of sensitivity

reduce it by using more sensitive equipment
using larger quantities of something

Question 2

percentage error

Answer 2

uncertainty
over
reading

x100

Question 3

gradient on a linear graph

Answer 3

change in y
over
change in x

Question 4

gradient on a curved graph

Answer 4

draw tangent
(meets line at point you want to know rate)

calculate gradient of tangent as linear
(y over x)

Question 5

what is a logarithmic scale?

Answer 5

log10 scale
each value is 10x large then last
- easier to plot very small and large number on same graph

use log button on calculator

Question 6

percentage change

Answer 6

final - original (change)
over
original

x100

Question 7

percentage increase/ decrease

Answer 7

+ change = increase
- change = decrease

Question 8

A as a % of B

Answer 8

A divided by B x100

Question 9

units

Answer 9

nano -> micro -> milli
x 1000

milli -> micro -> nano
/1000

Question 10

spearmans use

Answer 10

test for a correlation between 2 variables

Question 11

chi2 use

Answer 11

test for a significant difference between observed and expected

Question 12

t-test use

Answer 12

looks at significant difference between means

(null = no significant difference in means)

Question 13

how to calculate rate of reaction

Answer 13

change in DV
over
time

(unless DV is time = 1 over time)

Question 14

mitotic index

Answer 14

proportion of cells undergoing mitosis

number of cells with visible chromosomes
over
total number of visible cells

Question 15

cell in a stage of mitosis

Answer 15

number of cells in stage
over
total number of cells

x length of cell cycle

Question 16

percentage change in mass

Answer 16

change in mass
over
intial mass

x 100

Question 17

standard deviation

Answer 17

spread of data around a mean

larger = varied (less consistent)