What Is the Difference Between Epidermis and Cork in Structure and Function
Have you ever thought about what protects plants from adverse conditions or insects as these plants can't run in a dangerous situation? They have epidermis and cork cells to protect plant cells and tissues. The epidermis and cork are the outermost layer of the plant to provide protection.
They secret wax-like substances called the cuticle. It protects plants from water loss. These outermost layers also regulate gaseous exchange in plants.
What are Epidermal Cells?
The epidermis is the outer layer of the plant parts. It covers all the parts of the primary plant body. Epidermal cells are the primary component of the epidermis. In stem appendages, trichomes are also epidermal tissues. In leaves and stems, guard cells are also made of epidermal cells. The epidermis is mainly composed of parenchyma cells.
Functions of Epidermal Cells
The epidermis protects plants from water loss through transpiration because of the presence of a thick waxy layer called the cuticle.
The epidermis has root hairs that absorb water and minerals from the soil due to the large surface area.
It protects the plant from mechanical injury and other infections.
Epidermis also controls the gaseous exchange in plants.
It also controls or regulates the metabolic secretions in plants.
It also secretes various metabolic substances on the plant surface.
What are Cork Cells?
Cork is the outer protective covering of a tree. These are dead cells and do not have intercellular space. Cork cells are one of the parts of the bark, made of multiple layers of cells. When the bark of plant cells becomes old then it will be replaced by a secondary meristem.
Functions of Cork Cells
The following are the important functions of cork cells:
Like epidermal cells, these cells also prevent water loss from the plants.
It also protects the plant from various kinds of infections, especially fungal infections.
Protect plants from various injuries.
Similarity Between Epidermal Cells and Cork Cells
There are various similarities between epidermal cells and cork cells. Some of the similarities are given below:
Both epidermal cells and cork cells are the outermost covering of the plant body.
Both epidermal cells and cork cells control water loss from the internal structures of plants. These cells also ensure the correct exchange of air.
Both cork cells and epidermal cells lack chloroplast and hence they can't carry out photosynthesis
Both these types of cells release water-repellent substances.
Difference Between Epidermal Cells and Cork Cells
We have seen the similarities between epidermal cells and cork cells. But there are also many differences between these two types of cells. Some of the differences are given below:
Interesting Facts
Trees get 90% of their nutrition from the environment and only 10% from soil.
The wood is made of dead tissues that only provide mechanical support to plant tissue.
Stems of all plants are not hard, some are soft stems too.
Some plants grow from leaves. For eg., the African Violet is the plant that allows new plants to grow from leaves.
Important Questions
Q1. What is another name for cork?
Ans: The other name for cork is a phellem. It is a meristematic tissue that makes new cells through the process of mitotic divosion. Along with phelloderm and phellogen, it makes periderm.
Q2. Is cork water resistant?
Ans: Yes, cork is water resistant due to the presence of wax on the plant, which makes it water resistant. Due to its water-resistant property, it is used in many industries.
Q3. Why are epidermal cells and cork cells called protective?
Ans: Cork cells and epidermal cells are called protective tissues because they protect the plant from injury, water loss, and pathogenic attacks. They protect the plant from mechanical stresses.
Key Features
In this article, we have studied epidermal cells and cork cells.
These types of cells are present on the outer surface of the plant body.
Their main functions are to protect from mechanical stresses, and injury, prevent pathogens, and microbes, regulate gaseous exchange, and prevent water loss.
There are various similarities between epidermal cells and cork cells, such as they do not have chloroplast, and release water-repellant dance.
The differences between cork cells and epidermal cells are that cork cells form the outermost part of the secondary plant body, whereas epidermal cells form the covering of the primary plant body.
Practice Questions
Q1. How is cork formed from the epidermis?
Q2. What is cork and its function?
Q3. How is cork tissue formed?
Q4. Is cork a permanent tissue?
Q5. What is the epidermis?
FAQs on Difference Between Epidermis and Cork in Plants
1. What is the difference between epidermis and cork?
The main difference between epidermis and cork is that epidermis is the outermost protective layer of young plant parts, while cork is a protective tissue that replaces the epidermis in older stems and roots.
- Epidermis: Single layer of living cells covering leaves, young stems, and roots.
- Cork: Multilayered dead cells formed by the cork cambium (phellogen).
- Epidermis has stomata and cuticle; cork lacks stomata but has lenticels.
- Cork cells are impregnated with suberin, making them waterproof.
2. What is the epidermis in plants?
The epidermis is the outermost single layer of living cells that covers the primary body of a plant.
- Present in leaves, young stems, flowers, fruits, and roots.
- Secretes a waxy cuticle to reduce water loss.
- Contains stomata for gas exchange in leaves and stems.
- In roots, forms root hairs for absorption.
3. What is cork in plants?
Cork is a protective tissue made of dead cells that forms the outer covering of older stems and roots during secondary growth.
- Produced by the cork cambium (phellogen).
- Cells are filled with suberin, making them waterproof and air-resistant.
- Part of the periderm, which replaces the epidermis.
- Provides protection against mechanical injury and pathogens.
4. What are the functions of epidermis and cork?
The epidermis protects young plant parts and regulates gas exchange, while cork protects older plant parts and prevents water loss.
- Functions of epidermis: Protection, transpiration control, gas exchange, absorption (in roots).
- Functions of cork: Mechanical protection, prevention of water loss, insulation, and defense against pathogens.
5. Why is cork tissue dead while epidermis is living?
Cork tissue is dead because its cells are filled with suberin and lose their protoplasm at maturity, whereas epidermal cells remain living to perform metabolic functions.
- Cork cells: Dead, thick-walled, suberized.
- Epidermal cells: Living, with active cytoplasm.
- Epidermis needs living cells for secretion, absorption, and gas exchange.
6. What is the role of suberin in cork?
Suberin is a waxy substance in cork cell walls that makes the tissue waterproof and protective.
- Prevents excessive water loss.
- Blocks entry of pathogens.
- Provides resistance against mechanical damage.
- Gives cork its impermeable nature.
7. What is periderm and how is it related to cork?
The periderm is the secondary protective tissue that replaces the epidermis during secondary growth and includes cork as one of its components.
- Consists of phellem (cork), phellogen (cork cambium), and phelloderm.
- Forms in woody stems and roots.
- Provides protection in mature plants.
8. Do both epidermis and cork have stomata?
No, stomata are present in the epidermis but absent in cork, which instead has lenticels for gas exchange.
- Epidermis: Contains stomata in leaves and young stems.
- Cork: Lacks stomata.
- Gas exchange in cork occurs through lenticels.
9. In which parts of the plant are epidermis and cork found?
The epidermis is found in young plant parts, while cork is found in older stems and roots undergoing secondary growth.
- Epidermis: Leaves, young stems, roots, flowers, fruits.
- Cork: Woody stems and mature roots.
- Cork develops after the activity of vascular cambium begins.
10. How does cork replace the epidermis during secondary growth?
Cork replaces the epidermis when the cork cambium forms and produces layers of cork cells that push the epidermis outward.
- Step 1: Formation of cork cambium (phellogen) in the cortex.
- Step 2: Cork cambium produces cork (phellem) outward.
- Step 3: Epidermis ruptures and is replaced by the periderm.
- Result: Mature stem gains a protective outer bark.
