In the test for protein, why would some tubes show a slight purple color while others show a dark purple color?

protein:

1.What is the name of the reagent used to test for the presence of proteins? (1 point)

           Biuret reagent  

2.What color indicates the presence of protein in a solution when the reagent is added? (1 point)  

When Biuret is added, it would turn blue when it is negative but if it is positive then it would turn to a purplish to a dark purple. Showing that there is protein.

3.Which substances tested were positive for protein? (2 points)

The ones that were tested positive were milk solution and 50% egg solution.

4.Describe in your own words what we should do if the test tube for di-water tested positive for protein. (2 points)

Since Di water is our negative control, we know that there would be no proteins but if it was tested positive. Then we should start the experiment all over again this time with new, clean equipment.

the answer is "a.) well–developed vascular system."

explanation:

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d