Mathematics AS

Question 1

What factors affect the anount of gaseous exchange?

Answer 1

Size

Level of activity

Question 2

Peak flow meter

Answer 2

Measures rate at which air can be expelled from the lungs - often hsed for people with asthma to monitor lung function

Question 3

Vitalographs

Answer 3

More sophisticated versions of peak flow meter - breathe out as fast as possible showing amount of air against how quickly it is expelled

Question 4

What is forced expiratory volume?

Answer 4

Amount of air pushed out in 1 second

Question 5

Spirometer

Answer 5

Used to measure different aspects of lung volume/investigate breathing patterns

Question 6

What type of system is a spirometer?

Answer 6

Closed system with all of oxygen coming from within machine - so enough oxygen in chamber that person doesnt die

Question 7

Why does patient have nosepiece on?

Answer 7

Unable to breathe through nose giving more accurate representation of lung function

Question 8

Why does health matter with spirometer?

Answer 8

So that there are no diseases that impair lung function

Question 9

What feature is on spirometer?

Answer 9

Counterweight to prevent any resistance - does not have to breathe in and foce up/down the whole weight of the spirometer lid for example

Question 10

Why is there soda lime in spirometer?

Answer 10

All of CO2 produced (as a result of respirarion) is absorbed - which means that the trace eventually starts to decline as less gas breathed back into spirometer chamber than was breathed in - ONLY oxygen

Question 11

Breathe in…

Answer 11

Lid moves down - line moves up

Question 12

Breathe out

Answer 12

Lid moves up - line moves down

Question 13

What is tidal volume?

Answer 13

Volume of air that moves into and out of the lungs with each resting breath - it is around 500cm^3 with adults which uses about 15% of the vital capacity of the lungs

Question 14

What is vital capacity?

Answer 14

Volume of air that can be breathed in when strongest exhalation is followed by deepest possible intake

Question 15

Inspiratiry reserve volume

Answer 15

Maximum volume of air you can breathe in over and above a normal inhalation

Question 16

Expiratory reserve volume

Answer 16

Extra amount of air you can force out of your lungs over and above the normal tidal volume exhaled

Question 17

Residual volume

Answer 17

Volume of air left in lungs after exhaling as hard as possible - cannot be measured directly

Question 18

Total lung capacity

Answer 18

Total lung capscity = vital capacity + residual volume

Question 19

Label all of those features on spirometer

Answer 19

Total lung capacity = whole graph
Residual volume = bottom section
Tidal volume = height of normal breaths
Inspiratory Reserve volume = peak of tidal to top of graph
Inspiratory capscity = trough of tidal to top of graph
Vital capscity = everything except residual volume

Question 20

Breathing rate

Answer 20

Number of breaths per minute

Question 21

Ventilation rate

Answer 21

Total volume of air inhaled in 1 minute

Ventilation rate = tidal volume * breathing rate

Question 22

When body undergoes exercise?

Answer 22

Tidal volume increases from 15% to around 50% of vital capacity - breathing rate also increases thus increasing ventilation and so oxygen uptake during gaseous exchange can be increased to meet the demands of the tissues

Question 23

What is used to calculate Diversity?

Answer 23

Simpson’s index of diversity

Question 24

What does Simpsons include?

Answer 24

Species richness

Species evenness

Question 25

Range that Simpsons lies in?

Answer 25

0 and 1
0 = no diversity
1 = infinite diversity

Question 26

Formula of Simpsons

Answer 26

D = 1 - Σ(n/N)^2 
n = number of individuals of each species
N = all individuals of all species

Question 27

Standard Deviation

Answer 27

Square root : (sum(x-average)^2)/n-1
Where x = data value
n = number of values
x(bar) = average

Question 28

How to measure an outlier?

Answer 28

> or < mean +- (2*sd)

Question 29

Chi-Squared test

Answer 29

x^2 = (sum of (observed frequency - expected frequency)^2) / expected frequency

Question 30

Number of observations made?

Answer 30

The expected values depends on chance - ie if you toss a coin 10 times you get 5 heads and 5 tails but this is not always the case
If you increase the number of times the coin was thrown the difference between expected and observed decreases

Question 31

What does chi-squared help you measure?

Answer 31

The size of the difference between the results you actually get and your expected - whether these differences are significant or not
Chi squared is used to find out whether the difference is due to chance alone - thus allowing us to accept/reject the H0

Question 32

Degrees of freedom for chi squared

Answer 32

N-1 where n is the number of categories or possible outcomes present in the analysis
Yellow and green peas would be two categories and thus 1 degree of freedom

Question 33

If chi squares is less than critical value

Answer 33

Then we do not have sufficiently strong evidence to reject our null hypothesis as there is more than a 5% likelihood that this difference is due to chance - we accept null hypothesis

Question 34

If the calculated x^2 value is greater than critical value

Answer 34

We reject the null hypothesis as some other factor is likely to be causing a significant difference between expected and observed

Question 35

T test

Answer 35

Is used to compare the means of two sets of data and determine whether they are statistical,y significant or not

Question 36

Null hypothesis

Answer 36

No significant difference between two means and that any differences seen are due to chance

Question 37

How to calculate t test?

Answer 37

Calculate mean for each data set
Calculate standard deviation for each set of data (s1 and s2)
Square the standard deviation and divide by n1 and n2 respectively
Add those two values and take the square root of it
Divide difference between the two means with the value calculated in the step before to get the t value

Question 38

Degrees of freedom for a T-test

Answer 38

(n1 + n2) - 2 - unpaired ; different organisms/objects
n-1 for paired

Question 39

If t value is greater than critical value?

Answer 39

Reject the null hypothesis because there is less than a 5% chance that the difference is down to chance

Question 40

If t value is =/below critical value at 0.05

Answer 40

Then null hypothesis is accepted and there is no static tally significant difference

Question 41

Types of correlation

Answer 41

No correlation - no relationship between data
Positive correlation - as one set increases in value, the other set of data also increases in value
Negative correlation - as one increases the other set of data decreases

Question 42

What is the correlation test used to see?

Answer 42

If two different variables are correlated in a linear fashion in the context of a scatter graph

Question 43

Formula of spearman’s rank

Answer 43

r = 1 - (6(sumof)d^2)/(n(n^2-1))

Question 44

How to carry out a spearman’s rank

Answer 44

Data. For the two variables should be ordered from lowest to highest
If identical values exist then the average rank should be used - if two equal values appear
at rank 5 they are both assigned rank 5.5
Get rank difference d
Square it
Add them all up
Divide this by the number of pairs of data as n (shown in the equation)

Question 45

Rs value of +1
-1
0

Answer 45

\+1 = perfect positive correlation
-1 = perfect negative correlation 
0 = no correlation

Question 46

How to work out statistical strength of the correlation?

Answer 46

Value should be looked up in the correlation coefficient critical value tables - they will refer to the number of data pairs
For the data to be significantly significant, the spearman’s rank coefficient must be more than at 0.05% to give a certainty of more than 95%