Paper 2 Flashcards
(33 cards)
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
Suggest an advantage of AMPK during exercise
It allows fatty acids into mitochondria to be used as respiratory substrate
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
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
Explain why the treatment was not effective
Sterile males do not outcompete fertile males
Sterile population becomes insignificant
So sterilisation is not permanent
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
Explain difference between staining
Untrained mice have less myoglobin which is found in slow twitch muscle and contains stores of oxygen for aerobic respiration
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
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
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
Explain why tube 1 was set up
To show that there was no colour change without chloroplasts
To show chloroplasts were having the effect
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
What does reverse transcriptase do
Catalyses condensation reactions to form phosphodiester bonds between nucleotides
Why did the PCR stop
All the free floating nucleotides has been used up to make new dna strands
What is meant by phenotype
Observable characteristics of an organism determined by genetic and environmental factors
What type of gene interaction is the diagram displaying
Epistatsis
Work out offsprings genotypes phenotypes and phenotype ratio
Genotypes
Phenotypes: white:green:yellow
Ratio 2:1:1
Work out percentage that heterozygous Bb using hardy Weinberg
32%
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
Tick the box that incorrectly describes role of insulin
D~ activates glycogeneisis reactions
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
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
What is a gene pool
All genes in a population
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
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