Solved by a verified expert:1 of 25The mesopelagic zone refers to the ocean depths in which there isenough light to support plant light at all.dim light, but not enough for plant growth.enough light for primary production by bacteria.dim light, but enough to support only some hardy plants.Question2 of 25Where is the main thermocline located?In the mesopelagic.Above the mesopelagic.Below the mesopelagic.It varies since the thermocline disappears in the tropics.It varies since the thermocline moves up and down in the water column depending on the amount of oxygen.Question3 of 25Photophores arespecialized eyes.buoyancy-regulating organs.specialized jaws.light-sensitive organs that lack the lens of true eyes.light-producing organs.Question4 of 25Which of the following is not true regarding the deep-scattering layer (DSL)?Its position rises at night and moves down during the day.It is comprised of fish, shrimp, squids and jellyfish.It is found at depths of 300-500 meters.It was discovered by sonar.Its position is deeper on nights with a new moon.Question5 of 25The tubular eyes of some mid-water animals are adapted forincreasing the field of vision.producing light.seeing in the complete absence of light.sensing changes in depth.sensing changes in salinity.Question6 of 25The presence of bioluminescent organs on the underside of mid-water fishes is involved incountershading.enlargement of silhouette.creating a transparency effect.cryptic coloration.counterillumination.Question7 of 25Deep-sea pelagic fishes are characterized by all of the following exceptsmall eyes.absent or reduced swim color.flabby muscles.large mouth and teeth.Question8 of 25Which of the following is an important feeding adaptation among deep-sea fishes?Migration to shallower water to feedFeeding on males, hence the term “male parasitism”Ability to eat prey bigger than themselvesStrong muscles that allow them to move fast to catch any available preyAbsence of a stomachQuestion9 of 25Pheromones are special chemicals that are used todigest food.attract mates.catch prey.transport oxygen.produce bioluminescence.Question10 of 25The energy source for the bacteria that thrive around deep-sea hydrothermal vents ishydrogen sulfide.light.heat from the hydrothermal tissues.Question11 of 25The major advantage that deep-sea benthic animals have over pelagic ones is that their foodis easier to digest.falls to the bottom and stays in one place, thus being available for a longer time.gets to be eaten before it gets to pelagic animals.gets less decayed by bacteriaproduces less detritus.Question12 of 25A shrimp that occurs in large numbers around deep-sea hydrothermal vents does not have eyes. Light-sensitive cells on the top of the body, however, appear to be used to detect faint light frombioluminescent predators.the surface.faint glow around vents.bioluminescent prey.mates.Question13 of 25An unknown fish has been brought to the student to examine. This fish is black, relatively small with small eyes and weak, flabby muscles. This fish is most likely from which zone?Mesopelagic (vertical migratory)Mesopelagic (vertical non-migrator)EpipelagicDeep pelagicDeep-sea benthicQuestion14 of 25Traditional fisheries are those thathave their catches routinely recorded.catch shellfish, not not use boats.use relatively simple gear and not sell their catches to the general public.Question15 of 25Most marine food resources are taken fromcoral reefs.the continental waters off the continental shelf.estuaries.mariculture ponds.Question16 of 25By definition, pelagic catches are those that are harvested fromthe open water.the bottom.estuaries.waters where primary production is increased by upwelling.the continental shelf.Question17 of 25Trawls are nets thatsurround and trap fish.float on the surface.are allowed to drift along the surface.are placed along the bottom to trap passing fishes.are dragged along the bottom or through the water column.Question18 of 25The maximum sustainable yield is best defined as thehighest catch that can be taken without overfishing.maximum fishing effort allowed after overfishing is reached.highest catch that will pay the minimum cost of the fishing effort.minimum catch that will still allow the population to grow.the annual size of the catch that will balance natural death and predation.Question19 of 25Continued catches above the maximum sustainable yieldcan be increased to prevent overfishing.will result in underutilization.will result in a decrease of fishing effort.must be decreased in order to decrease population size.will result in overfishing.Question20 of 25Which of the following best describes commercial fisheries around the world?Most have been affected by overfishing.About 20% have been affected by overfishing.All have been affected by overfishing.All have been affected by overfishing but none have been exhausted.None in the Southern Hemisphere have been affected by overfishing.Question21 of 25The farming of salmon includes all the following problems excepthigher levels of contaminants in farmed fish tissue.pollution released into is more threatens genetic identity of wild increases parasitesQuestion22 of 25″By-catch” is the name given tounwanted species that are caught while fishing.species caught for industrial purposes.krill and other shellfish.species raised in fish farms.species caught as part of traditional fisheries.Question23 of 25Releasing farmed salmon fry to grow at sea and harvesting them when they return to the river where they were released is calledopen mariculture.closed mariculture.salmon ranching.traditional salmon runs.intensive mariculture.Question24 of 25Desalination plantsextract minerals for industrial use from seawater.convert seawater into fresh water.extract table salt from seawater.convert seawater into brackish water for industrial uses.extract oil from seawater.Question25 of 25Successful pharmaceutical uses for marine organisms include all of the following exceptred seaweed extract used for weight gain.sponge extract used as anti-inflammatory.squalamine from sharks used to treat cancer.bryostating from bryozoans used to treat cancer.horseshoe crab blood used to test vaccines from contamination.Perception is licensed to Rio Salado College