, PLEASE USE THIS DOCUMENT AS A GUIDE TO ANSWER YOUR ASSIGNMENT
QUESTION 1
1. Write brief notes on EACH of the following:
1.1. Structure and function of the cuticle.
The cuticle is a protective, waxy layer that covers the outer walls of epidermal cells, primarily found
on the aerial parts of plants. It plays a key role in the plant’s adaptation to life on land by acting as a
barrier to moisture loss and various environmental stressors.
Structure:
The cuticle is mainly composed of cutin, a fatty substance, along with epicuticular waxes that
form a thin film on the surface.
It can appear either amorphous or lamellate under the electron microscope.
The cuticle separates from the underlying epidermal cell walls via a pectinaceous layer.
There are two types of cuticle: primary, which forms as the epidermal cells expand, and
secondary, which develops after cells reach full size.
Cutinization refers to the process of impregnation of cell walls with cutin, while
cuticularization describes the polymerization of cutin on the surface.
Function:
The cuticle helps to prevent excessive moisture loss, a key feature for terrestrial plants.
It also acts as a barrier to airborne pollutants, keeping the plant protected.
The waxes on the surface make the cuticle hydrophobic, aiding in the removal of dust and
spores.
A thick cuticle can enhance mechanical stability of the plant's surface.
Its microsculpture can regulate surface temperature by reflecting light and reducing heat
absorption.
The cuticle contributes to plant defense mechanisms by forming a barrier to pathogens and
herbivores.
QUESTION 1
1. Write brief notes on EACH of the following:
1.1. Structure and function of the cuticle.
The cuticle is a protective, waxy layer that covers the outer walls of epidermal cells, primarily found
on the aerial parts of plants. It plays a key role in the plant’s adaptation to life on land by acting as a
barrier to moisture loss and various environmental stressors.
Structure:
The cuticle is mainly composed of cutin, a fatty substance, along with epicuticular waxes that
form a thin film on the surface.
It can appear either amorphous or lamellate under the electron microscope.
The cuticle separates from the underlying epidermal cell walls via a pectinaceous layer.
There are two types of cuticle: primary, which forms as the epidermal cells expand, and
secondary, which develops after cells reach full size.
Cutinization refers to the process of impregnation of cell walls with cutin, while
cuticularization describes the polymerization of cutin on the surface.
Function:
The cuticle helps to prevent excessive moisture loss, a key feature for terrestrial plants.
It also acts as a barrier to airborne pollutants, keeping the plant protected.
The waxes on the surface make the cuticle hydrophobic, aiding in the removal of dust and
spores.
A thick cuticle can enhance mechanical stability of the plant's surface.
Its microsculpture can regulate surface temperature by reflecting light and reducing heat
absorption.
The cuticle contributes to plant defense mechanisms by forming a barrier to pathogens and
herbivores.
