2020 P2 Flashcards
Explain how steroid hormones can rapidly enter a cell by passing through its cell-surface membrane (2)
LIPID SOLUBLE so can diffuse through phospholipid bilayer.
Suggest and explain why testosterone binds to specific AR (2)
SPECIFIC tertiary structure which is complementary
Suggest how AR could stimulate gene expression (2)
AR is transcription factor
Binds to DNA
Which stimulates RNA polymerase
What can you conclude from the data in Table 1?
CAG repeats) (3
With =<16 repeats the association is significant
With =<17 repeats the association is not significant
SO with =<16, REJECT null hypothesis
Explain how two features of the calorimeter shown in Figure 2 would enable a valid measurement of the total heat energy released (2)
STIRRER distributes heat energy
INSULATION reduces loss or gain of heat
Heat energy released in KJ per g of biomass (2)
3.3
In natural ecosystems most of the light falling on producers is not used in photosynthesis. Why (2)
Light is WRONG WAVELENGTH
Light doesn’t HIT chlorophyll
Two products of light-dependent reaction (2)
ATP
NADPH
Number of Chlorella cells in culture after 24 hours (2)
1.31 x 10^8
Describe how you could produce a calibration curve for creatinine (4)
Use water and creatinine solution to produce a dilution series
Add creatinine-detecting solution to each
Use known volume of diluted creatinine solution
Record absorbance of solutions using COLORIMETER
Plot dilution of creatinine solution against absorbance graph
Two causes of genetic variation (2)
Crossing over
Independent segregation
Name the relationship between the two alleles that code for flower colour (1)
CO DOMINANCE
Complete genetic diagram (tall pink/white flowers)
Ratio 1:1:1:1
Use Hardy-Weinburg equation to calculate the percentages of pink-flowered plants in this population. (2)
42%
Calculate how many times greater the mean growth rate per day was using 37.5g potassium nitrate than using 37.5g ammonium sulfate (1)
1.38
