The northern long-necked turtle (Chelodina rugosa) of tropical Australia always lays its eggs underwater-the only reptile in the world known for certain to do so consistently. Australian researcher Rod Kennett discovered the remarkable nesting habits of this turtle almost by accident. These turtles are commonest on tropical floodplains in Australia’s Northern Territory.Here, from December through April, monsoonal rains flood thousands of square kilometers, creating great shallow marshlands that dry almost completely in the near-rainless months outside the monsoon.As the waters recede, turtles retreat, if they can, to the few permanent water sources, or bury themselves in the drying mud to await the next coming of the rains.
1.What can be inferred from paragraph 1 about northern long-necked turtles?
A.They lay fewer eggs than other turtles do.
B.Many live in shallow marshlands from December through April.
C.They are most common in the dry areas of Australia’s Northern Territory
D.They retreat to other areas when monsoons threaten their nests.
Kennett could not understand why, no matter how common these turtles were in the billabongs (pools formed during the wet season) he was studying, he was unable to find a single nest despite two years of searching. ▉The Aboriginal people (the native people of Australia) knew the answer: they said that the turtles buried their eggs in the mud beneath the shallows as the rainy season came to an end, before the waters themselves dried.▉In 1991, Kennett and his coworkers tried an ingenious test of the Aboriginal answer. ▉They implanted tiny egg-shaped radio transmitters in the reproductive tubes of pregnant turtles at a lagoon near Darwin. When the turtles laid their eggs, the transmitters became part of the clutch (group of eggs), broadcasting the nests’ location. ▉This strategy for detecting turtle nests worked twice.The transmitters’ signals proved that the Aboriginals were right: both nests identified by the transmitters were underwater, buried beneath clumps of aquatic vegetation 17 meters and 14.5 meters,respectively, from shore.
2.The word “ingenious” in the passage is closest in meaning to
A.appropriate
B.comprehensive
C.clever
D.complicated
3.According to paragraph 2, all of the following are true of the test conducted by Kennett and his coworkers EXCEPT:
A.It provided information about the number of eggs in a turtle’s clutch.
B.It revealed the distance of turtle clutches from the shore.
C.It confirmed the information provided by the Aboriginal people.
D.lt was successful more than one time.
The transmitters solved one mystery but left the scientists with even greater ones. How do the eggs survive such treatment? And why do the turtles nest underwater in the first place? Flooding kills most reptile eggs because it denies them the oxygen they need to develop, and because water penetrating the shell may cause the egg to swell and the shell to crack. In some turtles, water entry is not necessarily a problem and may even be a normal part of development, as long as the underlying membranes surrounding the embryo remain intact. If these rupture, though, the embryo will likely die.Northern long-necked turtle embryos solve these problems by having a particularly water-resistant vitelline(innermost)membrane surrounding the yolk and the embryo and by simply not developing until the waters above them recede and air can reach the eggs. They can survive for at least 12 weeks in a state of arrested development-a remarkable feat considering that embryos of their close relative, the snake-necked turtle,will die after only about two weeks underwater.
4.In paragraph 3, why does the author discuss the embryos of the snake-necked turtle?
A.To describe the nesting habits of a close relative of the northern long-necked turtle
B.To introduce an additional discovery made by Kennett and his coworkers
C.To provide another example of embryos that have arrested development
D.To emphasize the exceptional ability of the eggs of the northern long-necked turtle to survive underwater
5.According to paragraph 3, how do the embryos of northern long-necked turtles differ from the embryos of other turtles?
A.They are not harmed if water enters the inner membrane of the egg.
B.They require less oxygen during the later stages of development.
C.They are surrounded by a special membrane that is not easily ruptured
D.They have very hard shells that protect them from swelling
Why do these turtles have such a bizarre adaptation?The answer probably has to do with the temporary and unpredictable nature of their watery habitat.Other tropical Australian turtles live in more or less permanent waters and nest on land in the traditional manner, even.apparently,including the newly described Arnhem Land long-necked turtle, which may be the northern long-necked turtle’s closest relative.Because they live in temporary floodwaters, though, northern long-necks may not be able to find a safe dry-land site at the right time of year. If the turtles lay on land during the rainy season, or toward the end of the dry season, their eggs may be flooded when the waters rise again, and flooding during the later stages of development, as opposed to immediately after laying, will kill even their embryos.Waiting until the waters recede at the end of the rainy season could delay nesting by several months, and cost them the chance to lay more than one clutch.
6.The word “bizarre” in the passage is closest in meaning to
A.useful
B.strange
C.complex
D.successful
7.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
A.Other than the Arnhem Land long-necked turtle and the northern long-necked turtle, tropical Australian turtles live and nest near permanent waters.
B.Other tropical Australian turtles, including a close relative of the northern long-necked turtle called the Arnhem Land long-necked turtle, live in permanent waters and nest on land.
C.The newly discovered Arnhem Land long-necked turtle is more closely related to the northern long-necked turtle than other tropical Australian turtles
D.The usual living and nesting habits of the northern and Amhem Land long-necked turtles are apparently different from those of other tropical Australian turtles.
By laying when they do, and where they do, northern long-necked turtles put their young in the best position to survive hatching. By having their eggs develop during the dry season, they ensure that their young will emerge only when times are right. If the hatchling turtles finish development before the dry season ends, the hard-baked ground over their heads will probably be impossible to break through. Only when the rains come again will the hatchlings be able to leave the nest, and only then will there be safe habitat for them to prosper in.
8.According to paragraph 5, when do newly hatched northern long-necked turtles leave their nests?
A.At the beginning of the wet season
B.During the dry season
C.At the end of the wet season
D.When the ground is dry enough
9.Look at the four squares [▇] that indicate where the following sentence could be added to the passage. Where would the sentence best fit?
While this would explain why Kennett couldn’t find a nest after such a long search, it was important for him to confirm that this was indeed the case.
10.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the 3 answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. (This question is worth 2 points.) Drag your choices to the spaces where they belong. To review the passage, click on view text.The northern long-necked turtle of tropical Australia lives in temporary floodwaters and exhibits unusual nesting habits.
A.The northern long-necked turtle is very important to Australia’s Aboriginal people, who have extensively studied the turtle’s nesting habits and behavior.
B.Using radio transmitters, researchers developed a test to determine whether northern long-necked turtles lay their eggs underwater.
C.Northern long-necked turtles’ embryos can withstand flooding better than other reptile embryos as a result of important structural and developmental differences.
D.The adaptations of northern long-necked turtles allow them to have higher survival rates than other turtles that live in permanent waters and nest in the traditional manner.
E.Northern long-necked turtles lay so many clutches because the majority of their young will be unable to survive underground until the dry season is over.
F.By laying their eggs underwater at the end of the rainy season, northern long-necks give their young the best chance for survival in their preferred habitats.
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