Flashcards in Paper 2 Deck (33):
1
Exercise increases heart rate explain how receptors and the nervous system are involved
•Increased muscle respiration
•Higher conc of co2 in blood
•Chemoreceptors in artery detects this
•Nervous impulses to sympathetic nervous system in the medulla oblongnata
•Increased frequency of nervous impulses to SAN
•Higher frequency of waves of excitation released
•Higher heart rate
2
Suggest an advantage of AMPK during exercise
It allows fatty acids into mitochondria to be used as respiratory substrate
3
Why would releasing sterile males would reduce the chance of the spread of infection in humans
Sterile males will compete with fertile males for resources and females
Carrying capacity of ecosystem for population does not increase
Overall smaller breeding population
Fewer chances of disease transmission
4
Explain how scientists would use the mark release capture method to determine population size
Collect your sample
Mark them using labels or pens that would not cause any harm
Release
Wait for a period of time
Collect a second sample
Calculate how many marked and unmarked species were caught and record data
Population size is worked using the following equation:
2nd sample previously marked/1st sample X 2nd sample
5
Explain why the treatment was not effective
Sterile males do not outcompete fertile males
Sterile population becomes insignificant
So sterilisation is not permanent
6
Explain why transgenic mosquitoes were released in week batches
Because the have a short lifespan
This would maintain population as they die out and the allele will become extinct as it will not be passed on
7
Explain difference between staining
Untrained mice have less myoglobin which is found in slow twitch muscle and contains stores of oxygen for aerobic respiration
8
Group b could last longer than group a explain why
Trained mice have a more slow twitch muscle so they are aerobically able to respire
Providing more atp than untrained mice as they mainly anaerobically respire so they have more atp for muscle contraction and therefore exercise longer. Which limits amount of Latic acid build up
9
What was the average diameter of each cell
Area/pi= R2
The square root of R2 = R
R x 2= Diameter
Diameter/15= mean
Mean from mm to um is x1000= 84.10
10
Suggest why water potential was the same
There was no water potential gradient that would draw water into Chloroplasts by osmosis
And potentially cause them to burst
11
Explain why tube 1 was set up
To show that there was no colour change without chloroplasts
To show chloroplasts were having the effect
12
Explain results in tube 3
As chloroplasts photosynthesise the produce NADP
DCPIP accepts the electrons to regenerate NADP
Causing it (NADP) to become reduced and changing colour
13
What does reverse transcriptase do
Catalyses condensation reactions to form phosphodiester bonds between nucleotides
14
Why did the PCR stop
All the free floating nucleotides has been used up to make new dna strands
15
What is meant by phenotype
Observable characteristics of an organism determined by genetic and environmental factors
16
What type of gene interaction is the diagram displaying
Epistatsis
17
Work out offsprings genotypes phenotypes and phenotype ratio
Genotypes
Phenotypes: white:green:yellow
Ratio 2:1:1
18
Work out percentage that heterozygous Bb using hardy Weinberg
32%
19
Why shouldn’t pancreas transplant be used for people with type 2 diabetes
Type 2 can be treated with regular exercise and diet
There’s no need to risk for surgery
Beta cells still produce insulin but insulin receptors are damaged so would be ineffective
20
Tick the box that incorrectly describes role of insulin
D~ activates glycogeneisis reactions
21
Describe how transcription factors turn adult skin in iPS
Negative transcription factors are used to stop expression of specialised genes
Positive transcription factors are used to activate expression of genes
22
Evaluate use of IPS cells in humans
Transplant was successful in mice as after first week there was similar blood glucose levels to non diabetic. But mice showed more fluctuations than non diabetic group
Although done on mice there could be possible unknown side affects in humans or treatment may not be effective in humans
As transplant cells maybe rejected by immune system
More trials are needed and a larger sample size to see trend as glucose levels were going up gradually after transplant in diabetic mice
23
What is a gene pool
All genes in a population
24
Explain how 2 species of palm trees came about due to sympatric seletion where their flowering times are different
•No gene flow between populations
•Mutation occurs
•increases chance of survival to reproduce
•offspring with beneficial allele produced will reproduce
•allele frequency increases
•mutation occurred in both populations
•populations diverge to the point of being different species as allele frequency changes. So can no longer produce fertile offspring
•
25
People develop AD every 30 seconds by what % did the amount of people increase
(1x2x60x24x365.5)/5400000 x 100
19.5%
26
Why does inhibition of acetylcholinerase improve nerve communication in AD sufferers
Acetylcholine is not broken down
Allowing it to repeatedly stimulate action potentials
Which makes up for lack of ach the person had
27
Why was the gene not removed by natural selection
Carriers of allele reproduce before age 49
Gene would be passed on regardless of mutation
As there’s no selection pressure against it
28
Why was the mutation expressed at different ages
Variance in lifestyle or environment leads to variance in epigenetic gene expressions
Variance in genome of individuals may lead to vulnerability against disease in other ways
Clinical signs appear later or earlier
29
Why double the sample size and only 74/75 mutations were said to be under threat of developing the disease
Two alleles of each gene both susceptible to mutation
30
Why test the whole genome and not use probe test for the GAC mutation
GAC triplet will not be unique to mutated allele and probe for that triplet will bind all over the place
31
How fungi get their nutrients
Decompose dead matter
Satrophytes absorb nutrients
Fungi absorb the nutrients from them through the cell wall
32
What does DNA polymerase do
Join two strands of dna together
33