雅思阅读 27: Light From the Living（来自生命的光）

改编自 Smithsonian Magazine / Science Advances（2026年5月）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://www.smithsonianmag.com/smart-news/these-marine-algae-glow-when-waves-disturb-them-their-bioluminescence-could-power-electricity-free-lamps-of-the-future-180988721/

Reading Passage

A. Bioluminescence is one of the stranger tricks in nature. It is also, by the standards of biological oddities, surprisingly common. Estimates suggest that as many as 90 per cent of deep-sea organisms — fish, squid, worms, jellyfish and bacteria — can emit light of their own making, the product not of reflection but of chemistry inside their cells. On land, fireflies and glow-worms have supplied poetic images for centuries. At sea, the same phenomenon appears as the blue flash of a wave breaking at dusk, or the fleeting blue trail of a boat's wake, or the eerie glow of a squid signalling to a mate in water too dark for sunlight to reach. Yet for all its familiarity, bioluminescence has stubbornly resisted being put to human use. The light lasts only milliseconds. Squeeze a glowing alga in a laboratory and it flashes once, as it would when a wave passes, and then falls silent for hours while it rebuilds its chemical reserves. In May 2026, a team at the University of Colorado Boulder reported in Science Advances a way to make the flash last — long enough, perhaps, to consider growing light itself.

B. The organism they chose is Pyrocystis lunula, a single-celled marine alga that drifts in sunlit surface waters. Like many dinoflagellates, it glows blue when mechanically disturbed. Inside each cell, an enzyme called luciferase speeds a reaction between oxygen and a molecule called luciferin; most of the energy released by the reaction emerges not as heat but as light, which is why bioluminescence is sometimes called "cold light". The name, from the Latin lucifer — light-bearing — was given in the seventeenth century, before anyone knew how the chemistry actually worked. In nature, the glow is thought to startle predators or to attract larger predators that might eat whatever is grazing on the alga, a kind of burglar alarm that calls in the guards. In the laboratory, it is a frustratingly brief event. The team's first instinct was to reproduce the mechanical trigger: to squish the cells in something like the way a wave would, with a plunger or a vibrating plate. "They weren't really responding to that," recalled Giulia Brachi, the study's lead bioengineer. Mechanical force, it turned out, was the wrong lever.

C. The lever that worked was chemical. Earlier work had hinted that Pyrocystis could be roused by other signals, and the team tried two. Some cells were placed in a solution roughly as acidic as tomato juice; others in one roughly as basic as mild soap. Both produced light, but they behaved differently. The basic solution gave a glow that was diffuse and short-lived — a signature, the researchers suspected, of cells under stress, using up their reserves in a panicked burst rather than a controlled display. The acidic solution, by contrast, produced a concentrated, steady blue that lasted as long as twenty-five minutes. It was, Brachi said, the first time anyone had managed to sustain the alga's luminescence. The difference, the team argued, lay in how the pH change reached the cell: gently, through the cell wall, rather than through the kind of abrupt mechanical shock that triggers a defensive flash. The acidic environment did not damage the cells; it simply kept the reaction primed, so that the luciferase and luciferin continued to combine at a slow, steady rate rather than in a single explosive pulse.

D. Sustained glow in a test tube is not, by itself, a technology. The next step was to build something with it. The researchers embedded the acid-treated algae in a water-based gel — essentially a transparent jelly that supplied moisture and nutrients — and 3D-printed the material into shapes: a crescent moon, a grid, the university's logo. The algae stayed alive inside the printed structures for four weeks, fed by the nutrients in the gel, and at the end of that period the acid-treated samples still retained about three-quarters of their original brightness. The printed objects were not lamps in any conventional sense; they did not produce enough light to read by, and they required a gentle periodic acid nudge to keep glowing, because the reaction's reagents eventually ran down. But they demonstrated that a living material, shaped into a useful form, could be made to emit light on demand without an electrical circuit, a filament or a battery. The team also noted, as an honest limitation, that the gel itself was not yet robust enough for outdoor use: it dried out, and the algae died if the temperature strayed too far from the cool sea water they were used to.

E. Why bother? The team's ambitions are deliberately speculative. A living light source would have no wiring, no power consumption and no disposable electronics; it could, in principle, be grown rather than manufactured, and it would repair and recharge itself as long as it was fed. They imagine it guiding autonomous robots in the deep sea, where batteries are hard to recharge and where bioluminescence is already the local lighting scheme, or lighting closed habitats in space, where every gram of hardware costs a fortune to launch. More prosaically, the work is a proof of principle that biology, rather than physics, can be engineered to produce light — an odd thought, given that humans have spent the last century persuading metals and semiconductors to do exactly that. The flash in the wave, for three billion years the sea's private joke, may yet end up as a lamp. Whether it ever lights a street, however, depends on solving the harder problem of making the algae glow bright enough, long enough, and cheaply enough to compete with an LED that costs a few pence. For the moment, the living lamp remains a laboratory curiosity — but a curious one.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. The chemistry that produces a flash ii. What happens when the trigger is chemical rather than mechanical iii. Why 90 per cent of deep-sea creatures glow iv. Growing a shape that emits light v. Where a living lamp might one day be useful vi. The history of firefly research vii. How 3D printers work

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. Why does Pyrocystis lunula normally glow only briefly? A. It runs out of luciferase. B. It flashes in response to mechanical disturbance and then stops. C. It needs electricity to glow. D. It is dead most of the time.

6. What was wrong with the team's first approach? A. They tried to reproduce mechanical disturbance, which did not sustain the glow. B. They used too much light. C. They worked with the wrong alga. D. They had no equipment.

7. How did the acidic solution compare with the basic one? A. It gave a diffuse, short-lived glow. B. It produced a steady glow lasting up to 25 minutes. C. It killed the algae immediately. D. It had no effect.

8. How long did the algae survive inside the 3D-printed gel? A. 25 minutes. B. Four weeks. C. Two days. D. Indefinitely.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. As many as 90 per cent of deep-sea organisms may be bioluminescent.
10. The enzyme that drives the reaction is called luciferin.
11. The basic solution produced a steadier glow than the acidic one.
12. The team received a $1 million grant from the US Navy.
13. The printed objects produced enough light to read by.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

The algae were embedded in a water-based (14) __________ and 3D-printed; the resulting living materials could one day light robots in the deep (15) __________.

答案与解析

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