Question

The pH of phloem sap is
A)8.7 -9.6
B)7.5-8.6
C)5.0-6.0
D)2.4-0.8

Answer 1

Hint: Phloem is an important vascular tissue in the plants which transports food prepared by the leaves to all the parts of the plant. Phloem sap mainly contains sugars, hormones and the dissolved minerals dissolved in liquid. The movement of the sap is from the food prepared to the part where it is used.

Complete answer:
To solve this question we must know about the components of the phloem sap and its uses.
The prepared food dissolved in water is called phloem sap. It mainly comprises carbohydrates, amino acids and hormones. Sucrose is the important carbohydrate present in sap. The sap is translocated through phloem. Phloem carries sap in both upward and downward direction from the sugar source (leaves) to sugar sink. The positive hydrostatic forces pull the phloem sap.

The sap is a thin watery and clear substance. For example maple syrup is the sap of maple trees. The pH of phloem sap is moderately alkaline that is around 7.5-8.6 whereas the pH of xylem sap is acidic.

Hence, the correct answer is option (B)

Note: The pH is the measure of hydrogen ion concentration in a solution. It is represented in numbers between 1-14. The pH 7 is considered as neutral. The pH less than 7 is acidic and pH greater than 7 upto 14 is considered alkaline. For example pH 1 is highly acidic and pH 14 is highly alkaline or basic.