Tap Root Diagram: Definition, Types, Examples, Diagram, Structure

Definition Of Tap Root

A tap root is the leading root of a seedling which starts from the radicle, growing vertically downwards; it usually appears thick and strong. One major reason that tap roots play a huge part in plant biology is that they can plunge far below for available water and store much-needed nutrients that some plants require for survival and growth in arid places.

Tap roots are, therefore, pretty essential in the growth of plants since they offer anchorage and increase the surface area for taking in nutrients. Indeed, they grow very deep into the soil, hence allowing plants to make use of water and minerals that other plants with shallow roots cannot. This deep root system also helped firmly anchor the plant into the earth, thus preventing uprooting by any wind or forces of water. Additionally, the tap roots may act as storage organs for key nutrients, allowing the plant to survive drought or periods when essential nutrients are limited.

Anatomy Of A Tap Root

The details are given below:

Root Cap

This is a covering of cells at the very end of the tap root that not only cares for the tender meristematic zone during its push through the soil but also guides and protects it from damage during that process.

Meristematic Zone

This zone, just behind the root cap and consisting of actively dividing cells, contributes to an increase in the length of the root. In this region are formed new cells that will later start to elongate and differentiate.

Elongation Zone

Cells that have been generated by the meristematic zone start to elongate in this area, hereby considerably increasing root length. This action will point the root further deeper into the soil.

Maturation Zone

In this zone, cells start differentiating into other cell types. It is in this region that root hairs develop, which is very important in increasing the surface area of the roots, hence a key part of the uptake of water and nutrients.

Types Of Tap Roots

The types of tap roots are:

Tap Root Primary

This is the main root growing from the radicle of the seed straight down. It's usually thick, deep, and stout, holding on firmly and allowing access to sources of water from way deep in. Examples are the dandelion and oak trees.

Lateral Roots

Lateral roots are essentially those roots which grow from the primary tap root and extend sideways, horizontally. They add to increasing the stretch of the root system, therefore stability and the overall uptaking of nutrients. They may form a dense network of roots in the upper layers of the soil.

Modified Tap Roots

Some tap roots become modified to serve special functions, in this case, storage. Examples are carrots, beets, and radishes. It is characteristic of these plants that the tap root becomes enlarged, storing nutrients and water for times of unfavourable conditions.

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