Osmoregulation：練習問題

• a.They must always be osmoconformers to survive in estuarine conditions.
• b.They are restricted to living only in high-salinity open ocean environments.
• c.They are able to survive in a wide range of different environmental salinities.
• d.They are organisms that do not possess specialized cells for ion transport.

• a.The transition from being an osmoregulator in the sea to an osmoconformer in rivers.
• b.Increasing the thickness of their scales to prevent all water movement.
• c.The ability to reverse the direction of ion pumping in specialized gill cells.
• d.The cessation of drinking water entirely when moving into higher salinity environments.

• a.

  Water will leave the cells by osmosis, causing the cytoplasm to shrink.

• b.

  Water will enter the cells by osmosis, causing them to swell and potentially lyse.

• c.

  Salt will diffuse out of the cells until the internal water potential reaches \(-100\) kPa.

• d.

  The organism will begin actively drinking the solution to balance the pressure.

• a.

  To actively excrete salt ions into the sea water.

• b.

  To increase the rate of osmosis into the blood.

• c.

  To store excess salts for use in metabolic reactions.

• d.

  To produce dilute urine to maintain blood volume.

• a.

  Because its internal water potential is lower than the surrounding sea water, leading to a gain of water by osmosis.

• b.

  Because its internal water potential is higher than the surrounding sea water, leading to a loss of water by osmosis.

• c.

  Because the sea water is hypotonic to its body fluids, causing salt to diffuse out of its gills.

• d.

  To prevent its cells from bursting due to the high volume of water it drinks from the environment.

まず自分で答えを書いてから、解説と照らし合わせましょう。

まず自分で答えを書いてから、解説と照らし合わせましょう。

まず自分で答えを書いてから、解説と照らし合わせましょう。