TOEFL IBT Listening Practice Test 11 Solution, Explanation & Transcripts

Questions 6 through 11.

Listen to part of a lecture in a botany class.

W: Several of the processes related to growth and aging in plants involve the effects of hormones. Today I’ll talk about two aging processes—the ripening of fruit and the falling of leaves in autumn. These processes involve a hormone called ethylene. What is ethylene? It’s a chemical, a gas produced by plants as a hormone. Ethylene is unique among plant hormones because it’s the only hormone that’s a gas. The gaseous state is important because it enables ethylene to move through the plant. Like all other hormones, ethylene triggers certain responses in the plant. Ethylene is associated with a variety of aging processes. One example of the aging process is the ripening of fruit. The ripening of fruit involves several changes in structure and metabolism. Some of these changes are aging processes. One change is the weakening of cell walls, which softens the fruit. Another is the decrease in chlorophyll content, which causes the fruit to lose its greenness. Ethylene initiates or hastens both of these changes and also causes some ripened fruit to drop from the plant. A chain reaction occurs during ripening, as ethylene triggers aging. The aging cells then release more ethylene. Because ethylene is a gas, the signal to ripen spreads from fruit to fruit. You’ve heard the expression “One bad apple spoils the whole lot.” Well, it really is true! Yes, Randy?

M: So, when we buy fruit, like peaches that are still kind of green, and we store them in a plastic bag, and the peaches ripen faster—is this because of ethylene? I mean, I think I get it. The bag traps the ethylene gas, and this speeds up the ripening.

W: Right. That’s exactly what happens. Ethylene accumulates inside the plastic bag, and this starts a chain reaction. The signal to ripen spreads from one peach to another, and this causes all of the peaches to ripen faster.

By the way, the role of ethylene was discovered in sort of an interesting way. A century ago, citrus growers used to ripen fruit by “curing” it in sheds that were heated by kerosene stoves. The growers thought it was the heat from the stoves that ripened the fruit. However, they later discovered that the fruit didn’t ripen after they started using newer, cleanerburning stoves. Botanists figured out that the reason the fruit ripened in the sheds with kerosene stoves was because of ethylene—not heat—because, as it turns out, ethylene is a by-product of kerosene combustion. Nowadays, a lot of fruit is ripened in huge storage containers that have ethylene gas piped in. It’s a new variation on the old curing shed. But in other cases, storage facilities have to slow down the ripening caused by natural ethylene. For example, apples are stored in bins that are flushed with carbon dioxide. Circulating the air with carbon dioxide prevents ethylene from accumulating, and carbon dioxide slows down the action of whatever ethylene isn’t flushed away. This is how apples can be stored for several months before they’re shipped to supermarkets.

Another aging process in plants where ethylene plays a role is the falling of leaves in autumn. When a leaf falls from a tree, the breaking point is a layer near the base of the leaf’s stalk. A change in the balance of two hormones—ethylene and auxin—controls the falling of leaves. An aging leaf produces less and less auxin, a hormone that stimulates cell growth. The drop in auxin makes the cells of the breaking layer more sensitive to ethylene. As the influence of ethylene becomes stronger, the cells start producing enzymes that weaken the cell walls of the breaking layer. Finally, with the help of wind or rain, the leaf breaks away at that layer and falls from the tree.

“An aging leaf produces less and less auxin, a hormone that stimulates cell growth. The drop in auxin makes the cells of the breaking layer more sensitive to ethylene. As the influence of ethylene becomes stronger, the cells start producing enzymes that weaken the cell walls of the breaking layer. Finally, with the help of wind or rain, the leaf breaks away at that layer and falls from the tree.” What does the professor imply about the falling of leaves?

Question 12 through 17.

Ml: Managers must manage. It’s a simple statement, but let’s think about what it means for a minute. Let’s ask ourselves, what makes a manager? Tammy?

W: A manager is someone who supervises other people … and plans and carries out projects.

M1: That’s right. A manager has the ability to set goals, and then to accomplish what he or she sets out to do. Business managers shoot for results. This means that once you set your business plan and budget for the year, you have to achieve the sales, the market share, the earnings—whatever you set out to do. Yes, Doug?

M2: But even the best managers can’t achieve every goal.

A lot can go wrong that’s beyond your control. Say, for example, the whole economy goes into recession— that would interfere with your goals, like your sales, for example. Sometimes things go wrong, no matter what you do.

M1: You could say that about life in general. We’re always being hit with things that are beyond our control. But good managers have to adjust to changing circumstances. They … they have to … but let me share a story I tell all my students. It’s about two promising young people of equal intelligence and ability. Both are college students, and both want to go on to a top graduate school of business.

The first student, May, hands in all of her assignments and does exactly what’s expected ot her. She receives good grades—mostly As with a few Bs—during her first couple of years in college. But then one year she gets the flu before final exams, and she performs poorly on her exams. As a result, her grade point average slips to just above a C. May tells herself that it wasn’t her fault, it was because she wasn’t able to study when she was sick, and she vows to do better next year. But something always happens to wreck May’s plans. Next year she misunderstands a question on the final and gets a C. May graduates with a B-minus average.

The second student, Kay, also wants to go to a top school, so she sets out to get an A average. She studies four hours every night. Her diligence and hard work pay off, and she gets all. As her first three years. Then, in her senior year, she runs into trouble with one of her courses, advanced accounting. She works hard, but the material is difficult, and she has a hard time solving some of the problems. At midterm she’s struggling for a B. She works harder, does some outside reading. She asks her professor for help, but the professor doesn’t have much time for students. What does Kay do? After trying several different approaches—studying harder, reading more, asking for help—what she ends up doing is finding a graduate student to tutor her. She works long and thinks hard. And, of course, you know the end of the story: Kay gets her A.

Now, what kind of manager is each student?

W:Kay is certainly a more successful student because she got all As.

M2:The first student, May, probably won’t get into a top business school because the top schools require you have to have a high grade point average, and she didn’t have that. So the other student, Kay, has a better chance of getting a topnotch business education.

M1:What you both said is true. But who’s the better manager: May or Kay?

W:In my opinion, May wouldn’t be a strong manager. She just drifted along. When she got the flu and blew it on her exams, she never really caught up. Kay is clearly the better manager.

M2:I agree with Tammy. I think Kay will be a better manager. She graduated with an A average, so that shows how hard she worked, but she also knew what to do when she was having trouble in her accounting course.

M1:Kay was a manager before she even reached business school. She had grasped the essentials of good business management—not because she worked so hard, but because when one action failed, she tried another, and another, until she achieved her goal. That is what managers do.