The Main Parts and Functions of the Carrot Root

The purpose of a root is to anchor the plant to the ground and absorb water and nutrients - diagrams below.

The root normally comprises 6 elements:

The root cap

Conical covering of the tip of the root which covers the apical meristem (undifferentiated cells). It protects against scratches while moving through the soil and excretes a mucus like substance called mucigel that allows the root to move through the soil easily.


Epidermis (skin)

Is the hard outer layer on a root absorbing water from surrounding soil through osmosis
Produces root hairs

Also known as the Peel, or periderm - Roots take water from the capillary spaces between soil particles. This function is carried out by the young portions of the roots at the location of minimal cutinisation of the epidermis and at maximum surface area. This location is found in the root-hair zone just proximal from the growing root tip. Thus roots take in their water through very fine roots located at the drip-line of the plant's canopy.


Root hairs

These are small, microscopic hairs on the outside of the epidermis and serve to increase the surface area of the root. They only survive for only a few days

The Cortex

Is located below the epidermis. Makes up the bulk of the primary root. Main purpose is to store starches. The sugar and carotene are contained in the Cortex.

The Cortex is comprised of the phloem, or nutrient conducting tissue - phloem conducts photosynthate from the leaves to the root tips. The metabolism of roots growing in the dark of the soil is essentially dependent upon respiration. This process requires carbohydrate or other organic molecules as fuel. It also requires a supply of oxygen, which is why soil needs to drain well for good plant growth.)

Endodermis

This is the thin layer of cells in the center of the cortex surrounding the xylem and phloem . It forces minerals into the xylem and phloem

Central Core

The Central Core comprised of xylem (a water conducting tissue, transporting water from root to leaf) All Roots contain xylem to conduct water from the soil up the plant and out through the leaves. These xylem tracheids and/or vessels are connected to others in an end-to-end design allowing soil water and minerals to be lifted up to the leaves. The evaporation of water from the leaves is the major pull of water through the xylem, but roots can also develop "root pressure" osmotically when the soil is well-watered and the plant has sufficient reserves.
 

For information here is the full classification of a carrot:

Kingdom Plantae – Plants
Subkingdom Tracheobionta – Vascular plants
Superdivision Spermatophyta – Seed plants
Division Magnoliophyta – Flowering plants
Class Magnoliopsida – Dicotyledons
Subclass Rosidae
Order Apiales
Family Apiaceae – Carrot family
Genus Daucus L. – wild carrot P
Species Daucus carota L. ssp. sativus- domestic carrot

(though there is whole disputed debate as to whether domestic carrot is drawn from the wild variety)

Note - Some classifications show Umbelliferae rather than Apiaceae

Next Page - The Carrot from 1800 to date