Question

How do the following structures help in respiration in plants?
A. Lenticels
B. Stomata
C. Root hairs

Answer 1

Lenticels are tissue in the bark of woody stems and roots of dicotyledonous flowering plants which are porous consisting of cells and with large intercellular spaces in the periderm of secondarily thickened organs meant for respiration. The stomata are defined as small pores in the epidermis of leaves, stem, and other organs which are meant for gas exchange. Root hairs are a hair-like expansion of vascular plants meant for water absorption via osmosis and are meant to dissolve mineral ions from the soil via active transport.

Complete answer:
In Option -A- Lenticels,
In hard and woody stems the gaseous exchange occurs via these lenticels these pores are present all over the bark. It provides a pathway for the exchange of gases between the tissues which are present internally in the atmosphere through the bark. The lenticels are formed beneath the stomatal complexes and the growth of these lentils are seen to be related to the growth and strength of the shoot. Lenticels continue in the new periderm as the stem and roots mature continuously. On stem and roots, these are found as raised portions which are oval elongated circular areas for the exchange of gases. In plants, woody thick barked these lenticels appear as rough, corky structures on young branches. In ants growing in oxygen-deprived areas, different plants having these lenticels are found for respiration for example mangrove species have these lenticels for respiration.

In Option -B- Stomata,
These are defined as small special pores found in the epidermis of stem, roots, and leaves meant for respiration. These pores are surrounded by special cells that are parenchymatous called guard cells which regulate the size of these pores.
Stomatal aperture - this term refers to the whole aperture including the stomatal pore and a pair of guard cells also known as stomatal aperture. Air entering through these pores via diffusion contains carbon dioxide needed for photosynthesis and oxygen used in respiration. The process by which water vapour diffuses into the atmosphere also occurs via these stomata. Most plants require stomata to be opened during daytime with the simultaneous loss of water vapor for the gaseous exchange i.e. for carbon dioxide to enter for photosynthesis.

In Option -C- Root hairs,
Root hairs also play an important role in the respiration of plants, these are the epidermal extensions of the roots in direct contact with soil via these hairs oxygen diffuses in and reaches to all cells of the roots. Mainly the respiration in roots occurs via diffusion of oxygen and carbon dioxide through these root hairs.
While roots help in water absorption they do not directly take part in respiration but provide water required for photosynthesis and the resulting product glucose made via this process is needed in respiration.

Note: Respiration in plants is defined as the process which involves the use of sugars such as glucose produced during the process of photosynthesis and oxygen taken via diffusion for the production of energy via this process for the growth of plants.