Third Timed Quiz
Make sure you open the AP equation sheet first
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AP Equation sheet
The figure above shows a model of a ligand precursor being cleaved to produce an active ligand that binds to a specific receptor. Which of the following is most likely to reduce the binding of the active ligand to its receptor?
A change in the cytoskeletal attachment of transmembrane proteins
The presence of a large amount of the precursor form of the ligand
An increase in the ratio of the number of unsaturated to the number of saturated fatty acid tails of the membrane lipids
A mutation in the receptor gene that causes a substitution of a charged amino acid for a nonpolar amino acid in the ligand binding site of the receptor
Which of the following provides the best indication that light is required for the activation of electron transfer reactions in chloroplasts?
Use the table and explanation for the next 5 questions
Calculating the rate of change of the absorbance for sample 1
Comparing the observed results for sample 2 and sample 3
Repeating the entire experimental procedure at night
Including multiple trials for all the samples
Which of the following can be reasonably concluded from the experimental results?
Chloroplasts must be suspended in a buffer solution to function properly.
The optimal temperature for activation of electron transfer is 25°C.
DCPIP inhibits biochemical reactions in suspended chloroplasts.
Light from a lamp can substitute for sunlight in stimulating chloroplast processes.
If an additional sample containing the chloroplast/DCPIP solution was placed at a distance of 90 cm from the lamp, which of the following predictions would be most consistent with the experimental results?
The concentration of DCPIP in the solution will increase exponentially.
The absorbance at 60 minutes will be roughly equal to 1.4.
The change in absorbance over time in the solution will be less than that of the other samples.
The temperature of the solution will exceed 75°C.
Which of the following descriptions of photosynthesis best explains the results of the experiment?
Availability of electrons for transfer to DCPIP depends on light energy.
Movement of DCPIP across chloroplast membranes occurs in less than 60 minutes.
Chlorophyll molecules degrade rapidly in the presence of DCPIP.
DCPIP can only be used to measurephotosynthetic activity at low light levels.
Which of the following scientific questions could be investigated using a similar experimental setup?
How much carbon dioxide is required by a plant cell to produce one molecule of glucose?
What wavelength of light best activates electron transfer reactions in chloroplasts?
Which molecule in chloroplasts accepts activated electrons from DCPIP during photosynthesis?
Are the same genes that are expressedin chloroplasts also expressed in mitochondria?
Some people have the ability to taste a bitter chemical called phenylthiocarbamide (PTC). The ability to taste PTC is due to the presence of at least one dominant allele for the PTC taste gene. The incidence of nontasters in North America is approximately 45%. Assuming the population is in Hardy-Weinberg equilibrium, what percent of the North American population is homozygous dominant for the ability to taste PTC? Provide your answer as a number between 0 and 1 to the nearest hundredth.
Based on the data shown, calculate the average rate of increase in oxygen consumption for animals acclimated to 5 degrees C as the temperature increases from 10°C to 30°C. Give the answer in mL O2/g/h/°C to the nearest tenth.
A certain species of plant has four unlinked genetic loci, W, X, Y, and Z. Each genetic locus has one dominant allele and one recessive allele. For a plant with the genotype WwXxYyZz, what is the probability that the plant will produce a gamete with a haploid genotype of Wxyz ? Give your answer as a fraction or as a value between 0 and 1, to four decimal places.