Daily Practice Questions

Explanation: In this problem, it is stated that the population is NOT in Hardy-Weinberg equilibrium, nor is this population under the conditions necessary for Hardy-Weinberg equilibrium. So the Hardy-Weinberg equations cannot be used. To find the frequency of the nontaster allele, total up how many recessive alleles are in the population and divide by the total number of alleles in the population. There are a total of 1,000 individuals (520 + 400 + 80 = 1,000), so there are 2,000 alleles in total. Each of the 400 heterozygous individuals contributes one nontaster allele (400 nontaster alleles), and each of the 80 nontaster individuals contributes two nontaster alleles (160 nontaster alleles) for a total of 560 nontaster alleles: \frac{560}{2,000} = 0.28 . Choices (B), (C), and (D) do not list the correct frequency.

Explanation: In the second paragraph, the author describes the tremendous impact that printing has had on human history, saying that it “changed the destiny of Europe,” and that it has “governed opinion,” reigning over the mind of man. So, this influence can best be described as “extremely significant.” It is not choice (B) because the influence of printing is relevant, not irrelevant. It is not (C) because the author suggests that printing has had a widespread influence, not that it has had a serious negative impact on society. It is not (D) because the impact of printing is more cultural, not militaristic.

Explanation: D —You may wish to review the Kinetics chapter if you have forgotten what the activation energy is.

Explanation: An ArithmeticException will be thrown at run time. Note that if N were of type double , no exception would be thrown. The variable sum would be assigned the value Infinity , and the error would only be detected in the output.

Explanation: Before we do any serious math on this problem, let’s see if we can get rid of some answer choices by Ballparking. First, we need to figure out what percent 54 is of 600. It’s pretty small, definitely way less than 50%, so we can eliminate (E) right off the bat. Now, think about easy percentages that you know—10% and 25%—and start from there. What’s 10% of 600? Just move the decimal one place to the left to get it, and you’ll find that 10% of 600 is 60. Therefore, if the number from the problem is 54, the answer must be less than 10%. Let’s get rid of (D). Now, we know that 54 is pretty close to 60, so we want something close to 10% but slightly less, and the only possible answer is (C).

Explanation: The correct answer is (D) because it maintains proper sentence structure by avoiding unnecessary punctuation within the compound object of the verb "decide." The phrase "what to leave and what to paint over" functions as a single noun clause, so no comma or colon should separate the two items. Choices (B) and (C) incorrectly insert a comma or colon that breaks the flow of this clause, while choice (A) lacks the necessary parallel structure for clarity.