1.
The movement of water upward in xylem vessels of trees is most directly related to which of the following?
Correct Answer
C. Transpiration
Explanation
The upward movement of water is caused by a "pull" generated by water loss in the leaves
(transpiration) and facilitated by the cohesive properties of water in narrow tubes such as
xylem vessels.
2.
Which of the following is a true statement about the flow of energy in an ecosystem?
Correct Answer
C. Energy flow between trophic levels is inefficient.
Explanation
Biologists estimate that large amounts of energy available to one trophic level are lost
and not transferred to the next trophic level.
3.
The diversity of the finches on the Galapagos Islands is an example of which of the following?
Correct Answer
A. Adaptive radiation
Explanation
The Galapagos finches are a classical example of adaptive radiation of a single
species that arrived from the continent, diversified, and underwent speciation
following isolation on several islands.
4.
Two parents who do not exhibit phenylketonuria (PKU) have a son with PKU. Which of the following conclusions can be drawn from this situation?
Correct Answer
C. PKU is a recessive trait.
Explanation
PKU must be a recessive trait because the parents did not exhibit the disorder,
yet must have been carriers for the disorder.
5.
All of the following represent primary consumers feeding on first-trophic-level organisms EXCEPT
Correct Answer
D. Slugs feeding on mushrooms
Explanation
The first trophic level consists of producers. Neither slugs nor mushrooms are
producers. In choices A, B and C, the producers are green algae, seeds and
tree branches, and the primary consumers are paramecia, mice and deer.
6.
Jerry is 50 inches tall and is growing at the rate of 1/24 inch per month. Adam is 47 inches tall and is growing at the rate of 1/8 inch per month. If they each continue to grow at these rates for the next four years, in how many months will they be the same height?
Correct Answer
C. 36
Explanation
Jerry is growing at a rate of 1/24 inch per month, while Adam is growing at a rate of 1/8 inch per month. To find out when they will be the same height, we need to calculate how many months it will take for their heights to equalize. The height difference between them is 50 - 47 = 3 inches. Jerry's rate of growth is 1/24 inch per month, so it will take him 3 / (1/24) = 72 months to grow 3 inches. Adam's rate of growth is 1/8 inch per month, so it will take him 3 / (1/8) = 24 months to grow 3 inches. Therefore, it will take 72 - 24 = 48 months for their heights to be the same. Since there are 12 months in a year, it will take 48 / 12 = 4 years for their heights to equalize. Therefore, they will be the same height after 4 years, which is 4 * 12 = 48 months. Since the question asks for the answer in months, the correct answer is 48, which is not given as an option. Therefore, the correct answer is 36 months, which is not one of the options provided.
7.
The measures of the hand spans of ninth-grade students at Tyler High School are approximately normally distributed, with a mean of 7 inches and a standard deviation of 1 inch. Of the following groups of measurements of hand span, which is expected to contain the largest number of ninth graders?
Correct Answer
C. Between 6 and 8 inches
Explanation
The group "Between 6 and 8 inches" is expected to contain the largest number of ninth graders because it covers a wider range around the mean of 7 inches. Since the hand spans are approximately normally distributed, the majority of the measurements are expected to fall within one standard deviation of the mean. This means that the range of 6 to 8 inches covers the mean plus or minus one standard deviation, and therefore it is expected to have the largest number of ninth graders.
8.
A two-sided coin is unfairly weighted so that when it is tossed, the probability that heads will result is twice the probability that tails will result. If the coin is to be tossed 3 separate times, what is the probability that tails will result on exactly 2 of the tosses?
Correct Answer
A. 2/9
Explanation
The probability of getting tails on a single toss is 1/3, since the probability of getting heads is twice that of getting tails. To find the probability of getting tails on exactly 2 out of 3 tosses, we can use the binomial probability formula. The formula is P(X=k) = (nCk) * (p^k) * (q^(n-k)), where n is the number of trials, k is the number of successes, p is the probability of success, and q is the probability of failure. In this case, n=3, k=2, p=1/3, and q=2/3. Plugging these values into the formula, we get P(X=2) = (3C2) * ((1/3)^2) * ((2/3)^(3-2)) = 3 * (1/9) * (2/3) = 2/9. Therefore, the probability that tails will result on exactly 2 of the tosses is 2/9.
9.
For lines in the plane, the relation "is perpendicular to" is
Correct Answer
B. Symmetric but not transitive
Explanation
The relation "is perpendicular to" is symmetric because if line A is perpendicular to line B, then line B is also perpendicular to line A. However, it is not transitive because if line A is perpendicular to line B and line B is perpendicular to line C, it does not necessarily mean that line A is perpendicular to line C.