Sea Life Adaptations in the Deep Ocean

Sea Life Adaptations in the Deep OceanMarine scientists identify several zones within the ocean’s vertical watercolumn, from the sunlit surface to the deep, dark floor. [▇] In the top layer,enough sunlight penetrates to allow photosynthesis and support a communityof abundant life. [▇] Below the sunlit zone is the mid-water level, called themesopelagic zone, which receives only dim sunlight. [▇] Fish and othercreatures in the mesopelagic zone have adapted to low light and low oxygenlevels. [▇]Common adaptations among hunters in the mesopelagic zone are sensitiveeyes and other light-detecting organs that perceive outlines and movement atlow light levels. Typically, such devices are a hundred times more sensitive tolight than human eyes. Predators and prey tend to adopt camouflagestrategies that involve body transparency, color patterns and photophores(light-producing organs) that break up the body outline, or, as in the case ofhatchet fishes, a body flattened from side to side to yield only a narrowsilhouette when viewed from below.According to paragraph 2, all of the following help predators in themesopelagic zone survive EXCEPTA.light-detecting organsB.the ability to see prey passing under themC.a flat bodyD.color patterns that disguise the body outlineThe word “perceive” in the passage is closest in meaning toA.followB.evaluateC.seeD.react to正确答案:CLook at the four squares [▇] that indicate where the following sentence couldbe added to the passage. Where would the sentence best fit?This level, sometimes referred to as the twilight zone, is not suitable forall aquatic organisms.Creatures living in the upper part of the mesopelagic, where light intensities are higher,are more likely to be transparent. Zooplankton that penetrate the deeper levels of themesopelagic are commonly orange, red, or purple but in the blue-green background lightare perceived as black or inconspicuous gray. Some mesopelagic fish have elongate(long and narrow) bodies, which may be a means of extending the length of the lateral line– a vibration-detecting organ – thereby raising sensitivity for detecting predators or prey.In paragraph 3, the author discusses mesopelagic fish with elongate bodies inorder toA.provide an example of how deep-sea organisms increase theirsensitivity to lightB.argue that extending the length of the lateral line helps animals blendin with their surroundingsC.explain the relationship between body shape and body transparencyD.describe an alternative to eyesight for detecting other animals in darkwatersMost mesopelagic animals are bioluminescent. This ability has evolved many times bydifferent mechanisms. Some organisms, such as the lantern fishes and bristlemouths,produce their own light, utilizing specialized tissue that is adapted for this purpose. Others,such as certain species of cod, harbor light-producing symbiotic bacteria that arecul...