Does the fairy shrimp require water?

Does the desert toad require water for reproduction?

Brine shrimps are one of only two known animals that can survive in highly saline waters. Writing in the Proceedings of the National Academy of Sciences, Artigas et al. report a biological innovation that might help these shrimps to achieve this extraordinary feat. Membrane-bound ‘pump’ enzymes regulate the levels of sodium and potassium ions in cells — exporting three sodium ions out of cells for every two potassium ions imported. In addition to the regular form of these pumps, brine shrimps produce a mutant form, the expression of which increases greatly in highly saline waters.7Mark for ReviewMCQABCWhich of the following, if true, most strengthens the author’s argument?AShrimp found in highly saline water have been found not to possess the pump enzymes whereas shrimp in freshwater do. BThe authors’ electrophysiology measurements on Brine shrimps confirmed that a larger-than-normal electrochemical gradient is maintained across the cell membrane and promotes survival in high salinity. CMutations in enzymes have been historically linked to increased survival rates of fruit bats introduced to new ecosystems and may be a factor in brine shrimp survival.DThe regular enzyme pumps are highly efficient methods of expelling sodium from the body of shrimps which help in survival in various environments in comparison to other animals.

Paragraph 6: In many parts of the ocean where bacteria and krill congregate in high densities tofeed on suspended particulate material, their metabolic activities deplete the water of availableoxygen, thereby creating the oxygen-minimum layer. Those organisms that exploit the detritus inthis layer or feed on other organisms found there must cope with low oxygen levels. The fish, thekrill, and the shrimp associated with this layer characteristically have large gills and blood that ishighly efficient at absorbing any available oxygen. Typically, such animals are also sluggish andadopt an opportunistic policy rather than actively hunting for prey. This way, they conserve energyand reduce their oxygen requirement. Their skeleton and musculature are reduced, and their bodyshape and form is subordinated to the need to remain floating in the water column with theminimum of muscular effort.7. Which of the sentences below best expresses the essential information in the highlightedsentence in the passage? Incorrect choices change the meaning in important ways or leaveout essential information.A: The oxygen-minimum layer occurs where high concentrations of bacteria and knll have depletedthe water of oxygenB: In many parts of the ocean, bacteria and krill gather in high densities to feed on suspendedparticulate matterC: Only krill and bacteria are common in the oxygen-minimum layer, because they need lessoxygen than other organisms.D: High densities of suspended particulate matter exist in the oxygen-minimum layer in many partsof the ocean.8. Which of the following can be inferred from paragraph 6 about predators in theoxygen-minimum layer?A: They are generally stronger than predators in other parts of the oceanB: They generally wait for their prey to come to themC: They spend most of their time swimming around, searching for preyD: They deplete less oxygen from the water than their prey do

Which of these species indicates very polluted water?Mayfly larvaFreshwater shrimpTubifex wormMayfly nymph

Acidic water hinders corals' ability to build a .