Read the following passage.
A. In sheltered bays and estuaries of eastern Canada, eelgrass forms underwater meadows rooted in soft mud or sand. It is the only seagrass that is widespread in Atlantic Canada, and along the western Atlantic its range reaches from the coast of Labrador south to North Carolina. The beds grow from the low intertidal zone down to about 12 metres in some areas. Eelgrass grows along the entire coastline of Prince Edward Island but is generally absent from rocky, high-energy coasts and very murky water. Without it, many of these shallow areas would be bare sand or mud flats.
B. Eelgrass is a perennial plant with a network of roots and rhizomes under the sediment. It thrives best in clear water, and the maximum depth a bed can reach depends on how much light gets to the bottom. The plant is tolerant of a wide range of salinity and can even survive fresh water for short periods. Warm water can weaken it and make it more open to disease. In the 1930s, wasting disease, caused by an organism similar to a slime mould, reduced eelgrass along the Atlantic coast of North America and in Europe by about 90 per cent, and the beds did not recover until the 1960s.
C. Eelgrass meadows rank among the most productive ecosystems on the planet. The plants filter the water, hold sediment in place and buffer shorelines. More than 20 kinds of seaweed in Atlantic Canada need eelgrass to complete their life cycle, using its blades for support. Snails, amphipods and other invertebrates are more plentiful in the beds than on bare sand or mud, and the cover reduces deaths from predators. The meadows also support more fish, and more kinds of fish, than unvegetated bottoms. The Atlantic Brant, a migrating water bird, feeds almost only on eelgrass where it can.
D. In 2009, a federal science review concluded that eelgrass in eastern Canada meets the criteria of an Ecologically Significant Species, which means that severe harm to it would affect the ecosystem far more than harm to most other species. Eelgrass has been lost in nearly all areas of intense human settlement. In parts of the Maritime provinces, beds have declined by 30 to 95 per cent, and possible causes include nutrient pollution, the invasive green crab and other human activity. In Newfoundland, local knowledge suggests a general increase. Once large meadows are lost, they can be extremely difficult to re-establish, even with transplants or seeding.
E. Not given in any of the above paragraphs.
Decide which paragraph, A to D, has the information given in each statement below. Select E if the information is not given in any of the paragraphs.
AI explanationShows the answer. Tap to open.
Correct Answer: C
Why this is correct: Look at paragraph C: more than 20 kinds of seaweed in Atlantic Canada need eelgrass to complete their life cycle. They use its blades for support. Holding onto the blades is how they get through their whole life.
Passage Reference: More than 20 kinds of seaweed in Atlantic Canada need eelgrass to complete their life cycle, using its blades for support.
Tips: Find the sentence where seaweeds depend on eelgrass. Check it also says why they 'hold onto' it.
Why the other options are wrong:
- A: In paragraph A, you read where the meadows grow and how deep they go. No other plant living on eelgrass is mentioned.
- B: The second paragraph explains what eelgrass itself needs, such as clear water and the right temperature. Seaweed does not come up.
- D: The fourth paragraph weighs how serious a loss of eelgrass would be for other species in general. But it names no seaweed that depends on it.
- E: The seaweeds that need eelgrass blades to finish their life cycle are counted in paragraph C.
Correct Answer: E
Passage Reference: The meadows also support more fish, and more kinds of fish, than unvegetated bottoms.
Why this is correct: In paragraph C, the meadows support more fish, and more kinds of fish, than unvegetated bottoms. That comparison is with bare seabed. Kelp forests are never mentioned, so this comparison is not made.
Tips: Paragraph C does make a fish comparison. Check what the meadows are compared with.
Why the other options are wrong:
- A: The first paragraph contrasts eelgrass with the bare flats that would exist without it. It has nothing on fish or kelp.
- B: Paragraph B covers light, temperature and disease, and neither fish nor kelp appear in it.
- C: Paragraph C is the closest, since it does compare fish numbers. But the other habitat in its comparison is unvegetated bottom, not kelp.
- D: In paragraph D, the topic is how eelgrass is declining and how hard it is to replant, not fish in other habitats.
Correct Answer: B
Passage Reference: It thrives best in clear water, and the maximum depth a bed can reach depends on how much light gets to the bottom.
Why this is correct: Notice that paragraph B says the maximum depth a bed can reach depends on how much light gets to the bottom. In other words, sunlight on the seabed sets how deep eelgrass can grow.
Tips: Look for what decides how far down a meadow can grow. Check that the reason is about 'sunlight'.
Why the other options are wrong:
- A: Depths such as about 12 metres are given in paragraph A. But it does not explain what sets that limit.
- C: The third paragraph lists what the meadows do for water, seaweed and animals. The depth of the beds is not discussed.
- D: Losses and a few gains are reported in paragraph D, but nothing about light or how deep eelgrass grows.
- E: Paragraph B explains that light reaching the bottom decides the greatest depth of a bed.
Correct Answer: E
Passage Reference: In parts of the Maritime provinces, beds have declined by 30 to 95 per cent, and possible causes include nutrient pollution, the invasive green crab and other human activity.
Why this is correct: In paragraph D, beds in parts of the Maritime provinces have declined by 30 to 95 per cent. Possible causes are listed. It never says who first noticed or reported the losses. So fishing crews are not mentioned.
Tips: Paragraph D tells you how much was lost. Ask whether it says who reported it.
Why the other options are wrong:
- A: Labrador and Prince Edward Island are named in paragraph A only to say where eelgrass grows. It says nothing about losses or who reported them.
- B: The second paragraph reports the huge losses of the 1930s but does not say who recorded them.
- C: In paragraph C, the writer describes how many animals use the meadows. No one reporting a loss appears there.
- D: The Maritime declines are counted in paragraph D, yet nobody is named as the first to report them.
Correct Answer: A
Passage Reference: It is the only seagrass that is widespread in Atlantic Canada, and along the western Atlantic its range reaches from the coast of Labrador south to North Carolina.
Why this is correct: Look at paragraph A: eelgrass is the only seagrass that is widespread in Atlantic Canada. A seagrass is a grass that grows in the sea, and widespread means common.
Tips: 'Just one kind' is a strong claim. Several places mention the Atlantic, so ask which one says no other sea grass is common there.
Why the other options are wrong:
- B: The Atlantic coast of North America comes up in paragraph B, but only for the 1930s disease. It does not say how many seagrasses grow there.
- C: Seaweeds and fish in Atlantic Canada fill paragraph C, but it never says eelgrass is the one common seagrass.
- D: The fourth paragraph is about the status and decline of eelgrass, with no claim about other seagrasses.
- E: The fact that eelgrass is the only widespread seagrass in Atlantic Canada appears in paragraph A.
Correct Answer: C
Passage Reference: Snails, amphipods and other invertebrates are more plentiful in the beds than on bare sand or mud, and the cover reduces deaths from predators.
Why this is correct: In paragraph C, snails, amphipods and other invertebrates are more plentiful in the beds. The cover also reduces deaths from predators. Fewer deaths from predators means these small animals are less likely to be eaten.
Tips: Many animals depend on these plants. Ask which part says hiding in them keeps 'small creatures' from being eaten.
Why the other options are wrong:
- A: The first paragraph describes the meadows and where they grow. It does not mention any animals.
- B: Paragraph B talks about a disease that killed eelgrass itself, not animals being eaten.
- D: In paragraph D, other species would suffer if eelgrass were harmed. But predators are not mentioned.
- E: Protection from predators for the small animals in the beds is described in paragraph C.
Correct Answer: A
Passage Reference: It is the only seagrass that is widespread in Atlantic Canada, and along the western Atlantic its range reaches from the coast of Labrador south to North Carolina.
Why this is correct: Look at paragraph A: along the western Atlantic, the range of eelgrass reaches from the coast of Labrador south to North Carolina. The statement gives the same coast and the same two end points.
Tips: Several paragraphs name places. Look for the one that gives both ends of the range.
Why the other options are wrong:
- B: North America and Europe are named in paragraph B as places hit by wasting disease, not the limits of where eelgrass grows.
- C: The third paragraph describes what the meadows do, not how far along the coast they reach.
- D: In paragraph D, the Maritime provinces and Newfoundland are named for losses and gains. But it gives no northern or southern limit.
- E: Paragraph A traces eelgrass from the Labrador coast all the way to North Carolina.
Correct Answer: D
Passage Reference: Once large meadows are lost, they can be extremely difficult to re-establish, even with transplants or seeding.
Why this is correct: At the end of paragraph D, the writer says lost meadows can be extremely difficult to re-establish, even with transplants or seeding. Transplants and seeding are ways of planting. So even this help may not bring a meadow back.
Tips: Two ideas must match: a meadow is gone, and planting it again does not work well. Only one place gives both.
Why the other options are wrong:
- A: Paragraph A says what shallow areas would look like without eelgrass, but not whether people can replant it.
- B: In paragraph B, the beds recovered by the 1960s after the disease. But people planting eelgrass are not mentioned.
- C: The third paragraph describes the benefits of healthy meadows. It does not discuss restoring them.
- E: The difficulty of re-establishing lost meadows, even with transplants or seeding, is the final point of paragraph D.
Correct Answer: A
Passage Reference: Without it, many of these shallow areas would be bare sand or mud flats.
Why this is correct: Look at paragraph A: without eelgrass, many of these shallow areas would be bare sand or mud flats. Bare flats have nothing growing on them.
Tips: Bare sand or mud appears in two paragraphs. Find the one that imagines the seabed without eelgrass.
Why the other options are wrong:
- B: The second paragraph explains the plant's needs and the old disease, not what the seabed would look like without it.
- C: Life in the meadows is compared with bare sand or mud in paragraph C. Yet it never claims the meadows would turn into such flats.
- D: The fourth paragraph says eelgrass has been lost near dense settlement. It does not describe what remains where it is gone.
- E: Paragraph A ends by saying these shallow areas would be bare sand or mud flats without eelgrass.
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