The Xylem in plants is responsible for transporting:
- (a)Oxygen
- (b)Amino Acid
- (c)Water
- (d)Food
Correct — C, Water. Xylem is the vascular tissue that conducts water and dissolved mineral salts from the roots upward to the stem and leaves. It is made largely of dead, thick-walled (lignified) cells — tracheids and vessels — that form continuous hollow tubes, and the water column is pulled up mainly by transpiration pull. Xylem transport is essentially one-way (upward).
- (a)Oxygen — Plants exchange gases such as oxygen and carbon dioxide by diffusion through stomata and lenticels, not through the xylem's water-conducting channels.
- (b)Amino Acid — Amino acids are organic (nitrogenous) solutes that move with the food stream in the phloem, not in the xylem.
- (d)Food — Food (sugars/sucrose made in the leaves) is transported by the phloem, in the process called translocation — this is the phloem's job, not the xylem's.
Plants have two conducting (vascular) tissues. Xylem carries water and minerals from roots to the rest of the plant; phloem carries food (sugars) from the leaves to wherever it is needed. A simple way to remember: xylem = water 'up', phloem = food 'around'. Xylem's driving force is transpiration pull; phloem transport (translocation) needs living cells and energy.
The trap is that all four options are things that move around a plant. The key is to separate the two transport tissues: water/minerals belong to xylem, while food and organic solutes such as amino acids belong to phloem; gases move by diffusion, not by a conducting tissue.
- Xylem transports water + dissolved minerals, roots → shoot (upward, one-way).
- Phloem transports food (sugars) and organic solutes like amino acids (translocation, both directions).
- Xylem is made of dead lignified cells (tracheids, vessels); driven by transpiration pull.
- Gases (O2, CO2) are exchanged by diffusion via stomata and lenticels, not by xylem.
The question tests the xylem's role — conducting water — the highlighted row.
- Swapping xylem and phloem — remember 'xylem = water up'.
- Assuming amino acids or oxygen travel in the xylem (they do not).
UPSC/UPPSC ask this directly ('xylem/phloem transports what?') or as a match-the-tissue-to-its-function item in basic plant biology.
No directly related past PYQ was found.
- practice — not a real PYQ
In plants, the transport of food (sugars) from the leaves to other parts is carried out by:
- (a)Xylem
- (b)Phloem
- (c)Cambium
- (d)Epidermis
Answer(b) Phloem — the process is called translocation.
- practice — not a real PYQ
The upward movement of water in the xylem of tall trees is explained mainly by:
- (a)Transpiration pull (cohesion-tension)
- (b)Active pumping by phloem
- (c)Gravity
- (d)Osmosis in the leaves only
Answer(a) Transpiration pull — water evaporating from leaves pulls the continuous water column up.