general exam tips Flashcards
why do the standard deviations differ
different groups have different spreads of data around the mean
what does it mean when the standard deviations overlap
-the data is not significant - so there is no significant difference in the values
what does it mean when the standard deviations dont overlap
-the data is significant - there is a significant difference between the means
estimate the value of the correlation coeffeicent of a postive correlation
-close to +1
-so between 0.5 and 0.99
estimate the value of a negative correlation coefficient
-close to 0
-0 to 0.5
sugegst some considerations that should have been taken into account to ensure that the study was reliable
-large sample size
-chose ppl randomly
-chose ppl with a range of ages
-equal number of males and females
-repeat readings/measurements
why do the shapes/size in the image appear to be different comapred to each other and in real life
shape- tissue has been treated/killed/damaged
size-cut through different sections/planes
patients recorded the intensity of pain, suggest two reasons why it was
important to use a statistically valid scale.
- (Sensation of) pain is subjective
OR
Pain sensitivity/threshold/tolerance varies; - To ensure that differences (in pain detection)
were (statistically) significant
OR
For (valid) comparison;
Suggest what the scientist should do to ensure that he has removed all the water from
the sample.
- Weigh and heat;
- (Until) mass is constant;
suggest one explanation for why the transmission reaction was less than 45 ms in trial 3
-student started to move her hand before the ruler was released
-ruler didnt fall vertically
-ruler stuck to skin
- student b held ruler to high
in response to touch, nerve impulses can be transmitted at speeds of 76.2 m s-1
-suggest three reasons why, in this investigation, the estimated speed of student A’s impulse transmission was less than 76.2 ms-1
-synaptic transmission OR transmission at a neuromuscular junction
-time for muscle contraction
-time taken for (stretch-mediated) sodium ion channels to open
-student may have been distracted/concentrating
-time taken for coordination/comprehension (by the brain)
if not asked for % of mitoitc index
do not times by 100
-just divide number of cells in mitosis by the total number of cells
give reasons why bacteria/ other organisms are able to use human DNA to produce human proteins
-genetic code is universal
-mechanism of transcription is universal
-mechanism of translation is universal
explain the importance of the marker gene
-shows that the gene has been taken up by the cells
-shows the transgenic/transformed cells
-allows detection of GM cells/organims
the enhancer only stimulates the region M in a certain area
-suggests reasons for the importance of the enhancer being included in the DNA fragment transferred
-milk/protein is easy to extract from a goat
-extracting milk does not harm the goat
-if gene was in the blood could prevent/affect clotting
-could damage other cells
