Question

Buttress roots are
A. Aerial
B. Underground
C. Aquatic
D. Horizontal

Answer 1

Buttress roots are modified roots that provide support to trees. It appears as vertically elongated basal sections of the stem.

Complete answer: The underground portion of a plant that grows and helps to anchor the plant securely in the soil is the root. The roots change shape in certain plants. These can get changed to absorb and move water and minerals from the soil to various parts of the plant. They are also modified for protection, storage of food, and respiration. For supporting the tree better, roots can get changed into these forms: prop roots, climbing roots, stilt roots, buttress roots, etc. Buttress roots form only in some species and are aerial extensions of lateral surface roots. Especially in shallow saturated soils, these roots stabilise the tree, thus resisting toppling. As a plate-like outgrowth of the trunk that supports the tree, the buttress root extends above the ground. Buttress roots are found mostly in tropical rainforest trees. Such roots grow horizontally, so they are able to cover a broader nutrient collection area. As all the main nutrients are present, they remain near the upper soil layer. Example: Bombax sp.
So, the correct answer is option D.

Note: Buttress roots are common in some wet lowland tropical trees. Few exceptions are there including bald cypress swamps. These types of roots are mostly absent in temperate region trees. Aerial roots are the ones which grow above-ground components. It can absorb water directly from the air. Aquatic plants have roots usually attached to the substratum but few have no such root system at all.