Dylan is on a strict vegan diet he does not consume meat, fish, eggs or dairy products. which nutrient is difficult to obtain naturally from a vegan diet. 1.vitamin a 2.vitamin b3 3.vitamin b12 4.vitamin c 5.vitamin e

3.Vitamin B12

Explanation:

Vitamin B12 is also called cyanocobalamin. It is the only B vitamin that is not present in any of the vegetables. The most common sources of vitamin B12 are liver, eggs, cheese, meat, kidneys, and milk.  

A vegan diet is the one that does not include any food product from animal sources. It also does not include any dairy products. Since vitamin B12 is found only in food products of animal origin and in dairy products, Dylan would not be able to obtain vitamin B12 from the vegan diet.  

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.