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TLS Online TPP Program

#Id: 10799

Many plants contain mixtures of volatile monoterpenes and sesquiterpenes, called essential oils examples- Peppermint, lemon, basil, and sage 

Chief monoterpene constituent of peppermint oil is menthol; that of lemon oil is limonene

#XL - R Botany #Secondary metabolites #Part B Pointers
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TLS Online TPP Program

#Id: 10714

#XL - R Botany

I. Tap root system

A single, thick Primary root, called Taproot, with smaller Secondary Roots going out from the sides
TLS Online TPP Program

#Id: 10715

#XL - R Botany

I. Tap root system

Tap root system found in Dicot Plants.

e.g., Mustard, Pulses, Fiscus, Mango tree, Banyan

Families- Brassicaceae, Lamiaceae, Rutaceae, Fabaceae, Moraceae, Malvaceae, Apocynaceae, Compositae, Rosaceae, Cucurbitaceae, Leguminosae, Solanaceae etc.
TLS Online TPP Program

#Id: 10716

#XL - R Botany

In monocotyledonous plants, the primary root is short lived and is replaced by a large number of roots called “Fibrous root system”

II.Fibrous root System

It develop from other than radicles

Many Small branching Roots, called fibrous root, but no large Primary root

The huge number of thread like roots increases the surface area for absorption of water and minerals

Fibrous root anchor the plant less securely

Fibrous root system

Fibrous root system found in Monocot Plants.

e.g., Maize, Paddy, Wheat, Grass, Onion

Families- Liliaceae, Poaceae etc.
TLS Online TPP Program

#Id: 10717

#XL - R Botany

Modification of root

Storage roots

Epiphytic or Aerial absorbing Roots e.g., Orchids.

Assimilatory roots

Respiratory roots or pneumatophores

Sucking roots or haustoria

Storage roots

Tap roots of carrot, radish, turnip and adventitious roots of sweet potato, dahlia get swollen and store food
TLS Online TPP Program

#Id: 10718

#XL - R Botany

Respiratory roots or pneumatophores
The roots of some trees and shrubs growing in saline marshes (mangrove plants) suffer from the lack of oxygen. Atmospheric air enters these roots through the minute pores of special lenticels (pneumathodes) on the exposed root tips.
TLS Online TPP Program

#Id: 10719

#XL - R Botany

Modifications to carry on special mechanical functions
1. Prop Roots- hanging structures that support a banyan tree

2. Stilt roots
Stilt roots of Sugarcane and Maize are supporting roots which arise from the lower nodes of the stem. These roots grow downwards and penetrate the soil and provide mechanical support to the plant.
Ex- Sugarcane  
3.Climbing roots
climbers can climb up their supports as adventitious roots growing from the nodes.
e.g., Pothos (money plant)