[amp_mcq option1=”xylem is surrounded by phloem” option2=”phloem is surrounded by xylem” option3=”xylem and phloem occur on the same radius” option4=”xylem and phloem occur on the different radii” correct=”option1″]
The correct answer is: A. xylem is surrounded by phloem.
Radial vascular bundles are those in which the xylem is surrounded by the phloem. This type of vascular bundle is found in the roots of plants. The xylem is responsible for transporting water and minerals from the roots to the leaves, while the phloem is responsible for transporting food from the leaves to the rest of the plant.
The other options are incorrect because they do not describe the structure of radial vascular bundles. Option B, phloem is surrounded by xylem, is the opposite of the correct answer. Option C, xylem and phloem occur on the same radius, is not correct because the xylem and phloem are arranged in a radial pattern in radial vascular bundles. Option D, xylem and phloem occur on the different radii, is not correct because the xylem and phloem are always in contact with each other in radial vascular bundles.