Question

In plants, food and other substances are transported through
a. Companion cell
b. Vessels
c. Sieve tubes
d. Tracheids

Answer 1

Hint: A vascular tissue that is responsible for the transportation prepared food, hormones and various amino acids from source tissues (e.g., photosynthetic leaf cells) to sink tissues (e.g. non-photosynthetic root cells or flowers).

Complete answer:
> Option A is incorrect. Companion cell is a type of cell that is located inside the flowering plant phloem. Typically, each companion cell is closely connected to a sieve unit. Its function is unclear, although it seems to control the behaviour of the adjacent sieve unit and to be involved in the loading and unloading of sugar into the sieve.

> Option B is incorrect. One of the cell types found in xylem is a vessel unit or vessel component, the water that conducts plant tissue. Typically, vessel components are present in flowering plants (angiosperms), but are absent from most gymnosperms including conifers.

> Option C is correct. The phloem is made up of sieve components, companion cells, parenchyma phloem cells, and phloem fibres. Sieve tubes consist of sieve elements that are elongated cells, connected to each other through sieve plates to form a continuous tube system that extends through the whole plant. They are the conduits of transporting food (mostly sugar).

> Option D is incorrect. Tracheids serve for water and mineral salt transport, they are elongated cells in the xylem of vascular plants. They are one of two groups of tracheary elements, and the other are vessel elements. Xylem tracheid occurs in all lower plants including gymnosperms and angiosperms. They function in all vascular plants for protection and upward conduction of water and dissolved minerals, and are the only such elements in conifers and ferns.

Hence, The correct answer is option (C).

Note: Phloem is the vascular tissue that contains the organic nutrients and distributes them. The phloem is also a signalling medium for molecules, and has a structural role in the plant body. This method of exporting food is called translocation.