Electrostatics and hydrophobic effects both contribute to stabilizing double stranded nucleic acids; which of the following best accounts for this? select one: a. the hydrogen bonding between bases (electrostatics) and base stacking (hydrophobic) b. phosphate-phosphate repulsion (electrostatics) and exclusion of water from the interior of the duplex (hydrophobic). c. repulsion between exocyclic amines on adenine, cytosine, and guanine and carbonyls on thymine, guanosine, and cytosines (electrostatics) and base stacking (hydrophobic). d. the hydrogen bonding between bases (electrostatics) and the repulsion of water from the backbone (hydrophobic). e. none of the above.

In tossing one coin 10 times, what are your chances for tossing a head? a tail? 2. in tossing one coin 100 times, what are your chances for tossing a head? a tail? 3. in tossing one coin 200 times, what are your chances for tossing a head? a tail? deviation = ((absolute value of the difference between expected heads and observed heads) + (absolute value of the difference between expected tails and observed tails)) divided by total number of tosses. this value should always be positive. 4. what is the deviation for 10 tosses? 5. what is the deviation for the 100 tosses? 6. what is the deviation for 200 tosses? 7. how does increasing the total number of coin tosses from 10 to 100 affect the deviation? 8. how does increasing the total number of tosses from 100 to 200 affect the deviation? 9. what two important probability principles were established in this exercise? 10. the percent of occurrence is the obtained results divided by the total tosses and multiplied by 100%. toss the coins 100 times and record your results. calculate the percent occurrence for each combination. percent head-head occurrence: percent tail-tail occurrence: percent head-tail occurrence:

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?

In response to framton's dialogue about his health issues, mr. sappleton replies: "no? " said mr. sappleton, in a voice which only replaced a yawn at the last moment. then she suddenly brightened into alert not to what framton was saying. what does this statement reveal about how mrs. sappleton feels about framton? a) she finds him boring. b) she's happy he came by. c) she finds him annoying. d) she feels sorry for him