question_answer

Most wild plants contain toxins that deter animals from eating them. A scientist discovered that a toxin produced by a certain plant was also toxic to the same plant if it was applied to the roots of the plants. As the first step in finding out why the plant was not normally killed by its own toxin, he fractionated some plant cell and found that the toxin was in the fraction that contained the largest cell organelle. He also found that the toxin was no longer toxic after it was heated. Which of the following statement are consistent with the scientist's observations?

(I)  The toxin was stored in the central vacuole.

(II) The toxin can cross the plasma membrane but not the membrane of the organelle in which it is stored.

(III) The toxin was stored in the chloroplast.

(IV) The toxin is likely to be lipid soluble.

(V) The toxin may be an enzyme.

A) (I),(II)and(V)

B) (I), (IV) and (V)

C) (II) and (III)

D)  (III) and (IV)