Hypertonic Hypotonic problem

[joonkimdds]

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Some protozoans have specialized organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
a) is isotonic to the protozoan
b) is hypotonic to the protozoan
c) is hypertonic to the protozoan
d) contains a higher concentration of solutes than the protozoan
e) None of the above choices are correct

answer is b)
my choice was c) even though I knew that C and D are the same answers.

if water is moving out of contractile vacuoles that means it always have more water than outside so shouldn't environment have less water than the protozoan and thus hypertonic to the protozoan?

 

[greenbean4606]

the reason the contractile vacuoles have to pump water out of the cell is due to the hypotonic environment that causes the inflow of water into the cell. There isn't going to be more water in a protozoan than it's environment, and the amount of water doesn't matter, it's the concentration. The need to have contractile vacuoles constantly working should cue you in on the fact that water is constantly rushing into the cell...characteristic of a hypotonic environment.

 

[Ex_EE]

Hypertonic - means that there is less solute present and therfore more water.
Hypotonic - means that there is more solute present and therefore less water.
Water always flows from hypotonic to Hypertonic areas.
Since water always enters the protozoan, the enviroment is hypotonic to the protozoan.

 

[Streetwolf]

Hypertonic - means that there is less solute present and therfore more water.
Hypotonic - means that there is more solute present and therefore less water.

Swap those.

 

[Ex_EE]

Whoops😳 That's what I get for writing a response before drinking my coffee in the morning. But water still flows from hypo to hyper.

 

[BenignDMD]

the reason the contractile vacuoles have to pump water out of the cell is due to the hypotonic environment that causes the inflow of water into the cell. There isn't going to be more water in a protozoan than it's environment, and the amount of water doesn't matter, it's the concentration. The need to have contractile vacuoles constantly working should cue you in on the fact that water is constantly rushing into the cell...characteristic of a hypotonic environment.

Yep, that is correct