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The function of all root hairs is to collect water and mineral nutrients in the soil to be sent throughout the plant. In roots, most water absorption happens through the root hairs. The length of root hairs allows them to penetrate between soil particles and prevents harmful bacterial organisms from entering the plant through the xylem vessels. [1]
Resorption of the root of the tooth, or root resorption, is the progressive loss of dentin and cementum by the action of odontoclasts. [4] Root resorption is a normal physiological process that occurs in the exfoliation of the primary dentition .
Active absorption refers to the absorption of water by roots with the help of adenosine triphosphate, generated by the root respiration: as the root cells actively take part in the process, it is called active absorption. According to Jenner, active absorption takes place in low transpiring and well-watered plants, and 4% of total water ...
The amount of water lost by a plant also depends on its size and the amount of water absorbed at the roots. Factors that effect root absorption of water include: moisture content of the soil, excessive soil fertility or salt content, poorly developed root systems, and those impacted by pathogenic bacteria and fungi such as pythium or rhizoctonia.
The mechanisms by which mycorrhizae increase absorption include some that are physical and some that are chemical. Physically, most mycorrhizal mycelia are much smaller in diameter than the smallest root or root hair, and thus can explore soil material that roots and root hairs cannot reach, and provide a larger surface area for absorption.
Adventitious roots arise out-of-sequence from the more usual root formation of branches of a primary root, and instead originate from the stem, branches, leaves, or old woody roots. They commonly occur in monocots and pteridophytes, but also in many dicots , such as clover ( Trifolium ), ivy ( Hedera ), strawberry ( Fragaria ) and willow ( Salix ).
They also increase the root's absorption surface, but this is a minor feature, as it also increases competition for nutrients against its own root clusters. [8] However, this adaptation leaves them highly vulnerable to dieback caused by the Phytophthora cinnamomi water mould, and generally intolerant of fertilization.
Example of aerial roots in the rubber fig (Ficus elastica) Due to the habitat in which R. apiculata occurs, the roots possess a special trait designed to anchor the plant to the soil. [4] [9] It still acts as a normal root through in-taking both water and nutrients with the only difference being it descends from the branches. Aerial roots ...