BIO question

[299678]

Freshwater fish that exist in hypotonic solution need to excrete large amounts of ---------------- through their kidneys to survive against osmotic pressure, whereas saltwater fish that exist in hypertonic solution need to consume large amount of ------------to reduce osmotic pressure?
a) salt water
b) water, salt
c) salt, salt
d) water, water
e) none of above

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[hausee]

both water....

freshwater fish is like drink too much water, so they excrete.

saltwater fish is like soak in salt and they are so thirsty and need a lot of water. at same time they get rid of salt.

😀

Freshwater fish that exist in hypotonic solution need to excrete large amounts of ---------------- through their kidneys to survive against osmotic pressure, whereas saltwater fish that exist in hypertonic solution need to consume large amount of ------------to reduce osmotic pressure?
a) salt water
b) water, salt
c) salt, salt
d) water, water
e) none of above

 

[299678]

yeah that's what I thought, but the correct answer is Water, Salt on DAT TO GO.

 

[hausee]

yeah that's what I thought, but the correct answer is Water, Salt on DAT TO GO.

I remember bio teacher said freshwater fish constant urinate and saltwater fish constant drink.Seriously, DAT TO GO need to check their answers. I've heard some errors coming from it.
👎

 

[prsndwg]

yeah that's what I thought, but the correct answer is Water, Salt on DAT TO GO.

if they do salt when they live in salt.. they will overdose 🙄

 

[ddslee]

yeah that's what I thought, but the correct answer is Water, Salt on DAT TO GO.

I think the answer should be water/salt....

1. fresh water needs to excrete large amt of water..so..and it seems like everyone is agreeing with it..so yea...

2. Salt needs to be consumed in order to keep the osmotic pressure..
even if you drink lots and lots of water...if environment is hypertonic, then you will be just thirsty as the beginning....so by consuming salt, decreasing osmotic pressure, thus less water is lost..

I think.....yea..

 

[hausee]

OK, let me ask you this, Does most saltwater fish taste like seawater? They should be if your explaination is right.

I think the answer should be water/salt....

1. fresh water needs to excrete large amt of water..so..and it seems like everyone is agreeing with it..so yea...

2. Salt needs to be consumed in order to keep the osmotic pressure..
even if you drink lots and lots of water...if environment is hypertonic, then you will be just thirsty as the beginning....so by consuming salt, decreasing osmotic pressure, thus less water is lost..

I think.....yea..

 

[299678]

Ok I got clear cut. They were right. the water from fish flow out in hyper tonic solution, so increase their concentration of salt. To reduce the increased osmotic pressure, they use their gill to excrete their salts by active transport.

 

[akeurogh]

It is water, water. If a saltwater fish is in a hypertonic environment, it is going to lose water to that environment, therefore increasing the concentration inside the fish. The only way to compensate for this loss is to drink water, not to take up salt.

 

[dentalpath]

it is water, water
Fish in saltwater need to consume more water and excrete salt more often..whereas fish in freshwater consume less water and conserve body salts..

 

[vinjennifer]

It is water, water. If a saltwater fish is in a hypertonic environment, it is going to lose water to that environment, therefore increasing the concentration inside the fish. The only way to compensate for this loss is to drink water, not to take up salt.

I think the viewpoint of this question is not surviving in the hypertonic environment but the reducing somotic pressure in the pypertonic environment. To survive in the hypertonic environment, the fish have to gain much water for losing water of the body. You are right in this viewpoint. However, this fish drinking much water in the hypertonic environment is caused to increase osmotic pressure more.

To reduce osmotinc pressure, this fish have to gain much salt and excrete small amounts of salt.
I have the DAT TO GO -biology. This book clearly mentioned the answer for this question.

 

[myheart01]

I think the viewpoint of this question is not surviving in the hypertonic environment but the reducing somotic pressure in the pypertonic environment. To survive in the hypertonic environment, the fish have to gain much water for losing water of the body. You are right in this viewpoint. However, this fish drinking much water in the hypertonic environment is caused to increase osmotic pressure more.

To reduce osmotinc pressure, this fish have to gain much salt and excrete small amounts of salt.
I have the DAT TO GO -biology. This book clearly mentioned the answer for this question.

I thik you are right. this is water, salt.

 

[AmpedUp]

My Gbio teacher harped on this distinction. It's B) Water, Salt
and I'm sooo sure

Freshwater fish - is getting a lot of water
Saltwater Fish - is getting a lot of salt

if you're getting a lot of something, then you must be getting rid of a little bit for the sake of balancing out your system. easy to remember?

 

[rippinitez]

Water, Water

Fresh water fish are hyperosmotic in relation to the surrounding water. Water constantly diffuses into the fish. Fresh water fish constantly urinate and absorb salts.

Salt water fish are hypoosmotic with environment. Water is constantly lost by osmosis and these fish must drink constantly.

 

[UCB05]

Alright, so every seems to agree freshwater fish have to excrete lots of water because they gain water in a hypoosmotic environment.

So what is it that saltwater fish do? They're in a hyperosmotic environment and constantly lose water. Consuming large amounts of salt to raise their internal osmotic pressure would screw up their physiology, not to mention does not solve the problem of water loss. In fact, saltwater fish have to excrete excess ions through concentrated urine and active transport out through their gills. With this in mind, it doesn't make sense to say saltwater fish consume salt to reduce osmotic pressure, only to waste more energy excreting it out later, right? They consume large amounts of water. The salt in the water is an unwanted addition that they get rid of later.

Amped, perhaps your teacher was saying freshwater fish excrete water and saltwater fish excrete salt. The question is what do saltwater fish consume.

 

[myheart01]

Alright, so every seems to agree freshwater fish have to excrete lots of water because they gain water in a hypoosmotic environment.

So what is it that saltwater fish do? They're in a hyperosmotic environment and constantly lose water. Consuming large amounts of salt to raise their internal osmotic pressure would screw up their physiology, not to mention does not solve the problem of water loss. In fact, saltwater fish have to excrete excess ions through concentrated urine and active transport out through their gills. With this in mind, it doesn't make sense to say saltwater fish consume salt to reduce osmotic pressure, only to waste more energy excreting it out later, right? They consume large amounts of water. The salt in the water is an unwanted addition that they get rid of later.

Amped, perhaps your teacher was saying freshwater fish excrete water and saltwater fish excrete salt. The question is what do saltwater fish consume.

Thank you for your good explanation.
However, I have a question. If the saltwater fish need to consume large amount of water to reduce osmotic pressure, then do you think the saltwater fish can survive in fresh water?
I would like to say "No" because the saltwater fish cannot control their osmoregulation in the fresh water and would die.
Saltwater fish also cannot survive in the hypertoinc environment without the regulation of osmotic pressure. The reason is that the water coming out of saltwater fish via gills and kidneys would be caused to die as a dehydration (or high osmotic pressure).
To solve this problem, saltwater fish have to drink much salt water and send the excess salt, which is absorbed from gastrointestinal system, to outside of the body via kidneys and gills in order to decrease osmotic pressure.
In this point the fish keeps the high concentration of salt in their bloodstream for not losing water through their kidneys and gills while they are pumping out salt.
During this process the saltwater fish gets water from the kidneys to survive physiologically. (Most students may confuse this viewpoint of the question!!)
Therefore, the correct answer is water, salt.

 

[AmpedUp]

Alright, so every seems to agree freshwater fish have to excrete lots of water because they gain water in a hypoosmotic environment.

So what is it that saltwater fish do? They're in a hyperosmotic environment and constantly lose water. Consuming large amounts of salt to raise their internal osmotic pressure would screw up their physiology, not to mention does not solve the problem of water loss. In fact, saltwater fish have to excrete excess ions through concentrated urine and active transport out through their gills. With this in mind, it doesn't make sense to say saltwater fish consume salt to reduce osmotic pressure, only to waste more energy excreting it out later, right? They consume large amounts of water. The salt in the water is an unwanted addition that they get rid of later.

Amped, perhaps your teacher was saying freshwater fish excrete water and saltwater fish excrete salt. The question is what do saltwater fish consume.

Had to look at this again, because I didn't catch "consume" and assumed it was excrete in the first part of the question stem. Shoot...I have to be really careful on the real deal.Water, Water makes sense now.

 

[N1264d]

Gotta love SDN. I was listening to a UC Berkely Bio lecture today that I had downloaded to help get me up to date on Bio. Good stuff. Anyway, the Professor addressed this question almost word for word. He said it is water, salt. I guess that is good enough for me.

 

[feri]

Water,Water 100%

 

[feri]

Let me correct my answer! the salt is in the water( there is plenty salt in hypertonic solution!!!) So, by drinking the water(which has salt!) it will reduce the osmotic pressure...So, I believe water,water 🙂