Question

Pneumatophores or breathing roots occur in
A.Hydrophytes
B.Epiphytes
C.Xerophytes
D.Mangrove plants

Answer 1

Pneumatophores or breathing roots are respiratory roots found in halophytes such as mangroves. They often grow in saline swamps, so breathing roots come out of the water to consume oxygen. A lot of carbon dioxide is also given out. This happens through small pores known as lenticels.

Complete answer:
Let’s discuss the options and find out the correct answer.
-Hydrophytes are those which have the ability to overcome the difficulty of consuming oxygen from water through intercellular air spaces in their stem, roots and leaves. Hydrophytes that are partially submerged have stomata in their floating leaves which helps them to exchange gases as in land plants.
-Epiphytes are organisms that develop on a plant’s surface and gain its nutrients and moisture from the air, rain, water (in case of marine environment) or from wastes collecting around it.
-Xerophyte is the category of plants which have the ability to survive in environments with very little liquid water such as desert, or places covered with snow or ice such as The Alps or Arctic region. They have specific adaptations to do this. Examples include cacti, pineapple and many others.
-Underground tissues need oxygen to respire and in case of mangrove plants, the oxygen content is very less or sometimes nil. For this purpose, mangroves have special roots which grow above the ground in order to consume oxygen from the atmosphere. They have a large number of pores through which oxygen enters the underground tissues.
Hence, option D: Mangrove plants is the correct answer.

Note: In areas where nutrients and oxygen are less inside the soil, the roots grow above the ground to overcome this difficulty. These happen when plants grow in areas where their surroundings are muddy. Hence, to have proper development, their roots come out of the land.