How Do Plants Excrete Waste? Explained with Diagrams and FAQs
Excess carbon dioxide and oxygen are expelled as plant waste products by the plants. The waste product of aerobic respiration in plant cells is carbon dioxide. A byproduct of photosynthesis is oxygen. Excess CO2 or O2 in the leaves exits through stomata to the air as part of the excretion process. They are also transported to the location where stomata are present to exit the plant body to the air by phloem and xylem from various areas of the plant body. Guttation and transpiration are additional methods of excretion.
Excretory Products of Plants and Their Uses
Plants create a large number of excretory products as a result of cellular respiration, photosynthesis, and other metabolic processes. Plant excretory products are carbon dioxide, extra water created during respiration, and nitrogenous chemicals produced during protein metabolism.
Two gaseous waste products, namely oxygen during photosynthesis and carbon dioxide during respiration, are produced by plants. Stomatal pores on leaves are used by plants to excrete gaseous waste. While carbon dioxide emitted during respiration is used for photosynthesis, oxygen released during photosynthesis is used for respiration. Additionally, extra water is expelled from the body of the plant through stomatal pores, as well as from the surfaces of fruits and stems. Transpiration is the term for the process of water evaporation.
In addition to gaseous wastes, plants' metabolism also produces organic by-products. These wastes are kept in various locations and various forms. Waste materials, including gums and resins, are kept in plant components like bark, stems, and leaves. Plants eventually shed these components. Different types of accumulated waste products include oil made from orange, eucalyptus, jasmine, and latex from rubber trees.
Following are the excretory products of plants useful to humans.
Oxygen is a byproduct of photosynthesis essential for human survival on earth and is produced as an excretory substance.
Tannin, another waste product from plants, is typically preserved in leaves and bark. Around the world, tea is made with it.
Plants store waste materials in their components, such as the leaves and bark that they regularly shed. These leftovers from sheds can be used to generate manure.
Essential oils are another plant waste product that is kept in the leaves of the plant. We employ these essential oils for a number of applications.
Adhesives are frequently made with gums that are taken from plants.
Resins are used to create glazing agents, varnishes, etc.
The tyre industry uses natural rubber, which is derived from rubber plants, as a raw material.
How Do Plants Excrete?
Plant excretory products are removed from the plant body by a variety of methods. The carbon dioxide created during respiration is used up during photosynthesis, and oxygen gas produced as a byproduct of photosynthesis is consumed during respiration.
The process of excretion in plants occurs in the following ways:
Through the stomata of leaves and lenticels of stems, oxygen, carbon dioxide, and water vapour are expelled as gaseous wastes.
Some waste materials gather in tree bark and leaves. The wastes are removed when the leaves and bark are shed.
Some waste materials are made harmless before being stored inside the body of the plant as solid objects. These wastes include raffia, tannins, resins, gum, rubber, and essential oils.
Different types of stored waste products include oil made from eucalyptus, and jasmine trees, latex from rubber trees, papaya trees, and acacia gums. Even excretion of these compounds into the soil occurs occasionally.
The process of guttation takes place in hydathodes located in the leaf epidermis of some plants. In a humid environment, plants secrete water and its solutes through a process called guttation. Water evaporation from the surface of leaves occurs during transpiration through the stomata. Excess amino acids in terrestrial plants are converted by deamination into uric acid and keto acids, which are then deposited as crystals in the leaves and excreted down the leaves. Salt glands present in halophytes excrete surplus salts in the body.
Excretion in Plants Diagram
How Do Leaves of Plants Help in Excretion?
In plants, leaves are crucial to excretion. The majority of carbon dioxide leaves the plants through stomata in leaves. The majority of the waste materials are kept in the plant's leaves, which also serve as a storage area. Plants expel leaves to get rid of waste materials. Excretion in plants pdf can be downloaded from Vedantu sites for better understanding.
Interesting Facts
Water is eliminated from plants by transpiration.
Gums and resins stored in the bark are reported to be expelled from the lenticels.
Important Questions
1. What are stomata?
Ans: In the epidermis of tree leaves, there are cell structures called stomata that play a role in the exchange of water and carbon dioxide between plants and the atmosphere.
2. What are resins?
Ans: Plant cells produce resins as a defense mechanism against injury or infection in trees and shrubs.
Key Features of Excretion in Plants
The process of water droplets being excreted from vascular plants' pores, such as grass, is known as guttation.
Stomata, stem lenticels, the outside of stems, fruits, etc., are the places through which gaseous wastes and water are expelled.
FAQs on Excretion in Plants: Definition, Importance & Examples
1. What is meant by excretion in plants?
Excretion in plants is the process of eliminating metabolic waste products. Unlike animals, plants lack a specialised excretory system. They get rid of waste through various methods, such as transpiration, diffusion, and storing waste in different body parts like leaves, bark, and vacuoles which are then shed.
2. What are the main excretory products in plants?
Plants produce several types of waste products through their metabolic activities. The main excretory products include:
- Gaseous Wastes: Oxygen from photosynthesis and carbon dioxide from respiration.
- Liquid Wastes: Excess water is removed through transpiration.
- Solid Wastes: Plants store solid wastes as secondary metabolites in their leaves, bark, or old xylem. These are often in the form of resins, gums, tannins, and latex.
3. How is the process of excretion in plants different from that in animals?
The primary difference is the absence of specialised excretory organs in plants. Animals have complex systems (like kidneys) to filter and remove complex nitrogenous wastes like urea. Plants, having a slower metabolic rate, produce simpler wastes. They remove gaseous waste via stomata and lenticels, and store other wastes in parts that are eventually shed, such as leaves and bark. Animal excretion is a much more active and complex process.
4. Why don't plants have a specialized excretory system like animals?
Plants do not require a specialised excretory system for several reasons. Firstly, their metabolic rate is significantly lower than that of animals, resulting in less waste production. Secondly, many plant 'waste' products, like carbon dioxide from respiration, are reused as a raw material for photosynthesis. Lastly, plants can effectively store waste products in cellular vacuoles or in dead tissues like heartwood, or shed them along with falling leaves, making a complex system unnecessary.
5. What is the importance of storing waste products in vacuoles and leaves?
Storing waste in vacuoles and leaves is a crucial survival strategy for plants. By isolating toxic or unwanted substances in the cellular vacuoles, plants protect their active cytoplasm from harm. Storing wastes in leaves is a method of permanent removal, as these leaves are eventually shed from the plant through a process called abscission. This mechanism allows plants to dispose of accumulated waste without needing a dedicated excretory system.
6. Are the excretory products of plants always useless?
No, many excretory products from plants are not useless and have significant commercial and ecological importance. For example:
- Gums and Resins: Used to make adhesives, varnishes, and perfumes.
- Latex: The source of natural rubber.
- Tannins: Used in the leather tanning industry.
- Essential Oils: Such as eucalyptus and sandalwood oil, are used in aromatherapy and medicine.
7. How do plants remove gaseous waste from their bodies?
Plants primarily remove gaseous waste through tiny pores on the leaf surface called stomata. During the day, excess oxygen produced during photosynthesis diffuses out through the stomata. At night, carbon dioxide produced during respiration is released. In woody stems, gaseous exchange also occurs through small openings in the bark called lenticels.
