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A system is defined as a set of interrelated or interdependent objects that function as a whole. In biology, it is defined as a biological or body system. A group of organisms that function together to carry out a particular task is referred to as a biological system.
The human body is comprised of different biological systems that are made up of biological organs. The particular biological system performs a specific function in the body. The classification system is another biologically relevant concept, which includes various procedures, characteristics, and definitions used to classify living things.
What is System?
The word system is derived from the Latin word “system”. The word system is used to describe the relationship between several working elements. The main purpose of building a system is to produce one or more specific goals.
We face various systems in our daily life, for example, the transportation system, the accounting system, the computer system, etc. the system is commonly defined as an entity including group components that are interconnected according to their specific function. A system must achieve the following criteria:
• A predetermined outcome can be obtained by a system.
• The central outcome gets priority over the outcome of each subsystem.
• The components should be interdependent.
A system can be simply defined as a group of integrated components that function together to achieve a specific goal. Examples include a disk subsystem that is a part of the computer system. Any system comprises different components or inputs that undergo processing and produce output.
A biological system is another example of a system. Living beings are also comprised of various biological systems such as digestive systems, respiratory systems, etc. A system is made up of several organs, for example, a digestive system includes the mouth, stomach, intestines, accessory organs that function together to digest food.
Components of a General System
Each system is comprised of components or inputs, outputs, and goals that serve the main system and achieve an ultimate goal.
Inputs or components are used by the system to obtain the output. The input can be money, facilities, people, time, and ideas. For example, a system has to obtain an outcome of training students, here the students, teachers, and training material will be the input that functions together to obtain the outcome of trained children.
The results obtained from the system are called outputs. The interactions of the inputs of systems result in the production of an output. The goals of the system are also described as missions, accomplishments, or purposes.
Types of Systems
A system can be of different types, however, they all have the same characteristics such as all are made up of various elements that are interconnected. The system can be classified as a natural system an artificial system. Other types of systems are open and closed systems.
Natural vs Artificial Systems
Natural systems are naturally designed that do not show a distinct output, but they are essential for life on earth. Besides this, artificial systems are man-made systems that give an output using various inputs. The design of an artificial system should be similar to avoid system failure. To detect the system’s defects and to check the output, the components of the system are periodically evaluated.
Open vs Closed vs Isolated Systems
The systems are classified as open, closed, and isolated systems. The systems that exchange energy and matter with the surrounding environment are called open systems. An example of an open system is boiling water in an uncovered pot where heat and vapor exchange with the surrounding air.
The systems that exchange only energy with the environment are referred to as closed systems. For instance, boiling water in the covered pot is an example of a closed system in which only heat will exchange with the surroundings.
The isolated system does not exchange energy or matter with the surroundings. An example of an isolated system is hot water in a thermos that cannot exchange heat or water vapor with the surrounding environment.
The systems in living beings are an example of open systems that exchange both energy and matter.
The common examples of a system are described below:
i. The Solar System
The system is the universe from where the earth belongs is referred to as the solar system. The solar system consists of specific definite paths in which the planets orbit in a disc-like manner. Solar systems contain the sun, planets and small rocks called the asteroid belt.
ii. Earth System
Four major types of systems in the earth include (1) geosphere, (2) hydrosphere (3) atmosphere (4) biosphere. Land and rocks are represented by the geosphere that forms the external and internal surface of the earth.
All water bodies including salty and freshwater are represented by the hydrosphere. Saline water consists major portion of the hydrosphere, which cannot be used for many purposes without processing. All the gases or mixture of gases including CO2, oxygen, nitrogen, hydrogen, ozone, and argon are present in the atmosphere. These gases protect from the harmful ultraviolet rays of the sun.
The lining part of the earth is called the biosphere. All the living organisms including plants, animals, fungi, and bacteria live in the biosphere. All the systems are integrated and affect other systems also if affected itself.
Raining is an example of an interconnected system. The interconnections between the earth systems are also causes of natural phenomenons including tsunamis, volcanic eruptions, and alterations in the components of the atmosphere. All the earth’s systems get affected by human activities. For example, the increasing concentration of greenhouse gases is causing global warming and climate change.
iii. Ecological Systems
It is made up of biotic and abiotic components. These components function together as a unit and are interrelated with each other. The biotic components are the living organisms whereas abiotic components consist of non-living or physical components. Both living and non-living things are interconnected by nutrient cycles.
The ecosystem gets energy from the sun that is utilized by producers or green plants. Animals get nutrition from these plants and further contribute to the flow of energy in the system. The dead organic material of the system is decomposed by the decomposers and detritivores.
Several internal and external factors influence the ecosystem. Shading, decomposition, and species present in the ecosystem are some examples of internal factors. External factors include various materials that form the soil and atmosphere. The availability of energy in an ecosystem is also determined by external factors such as climate. The material by which soil is formed is another important factor that determines the availability of minerals and nutrients.
iv. Biological Systems
These systems are comprised of different biological structures or organs. Examples of biological systems are the respiratory system, digestive system, and circulatory system.
• Respiratory system: the system performs the vital function of breathing and gaseous exchange in living beings. The organs include two lungs, the pharynx, the larynx, bronchi, and the diaphragm.
• Digestive system: digestion of food completes in the digestion system. The process of digestion includes several steps including intake, absorption, breakdown, digestion. The digestive system includes body organs such as salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines rectum, and anus.
• Cardiovascular system: The delivery of blood containing nutrients, and oxygen is carried out by the cardiovascular system. It also maintains the internal temperature and pH of the body. The heart is the main component of the circulatory system that pumps blood throughout the whole body.
• Nervous system: it is one of the important biological systems. It helps in the signal transduction through nerves to all body cells. It includes the peripheral nervous system and central nervous systems that are composed of body organs such as the brain, spinal cord, and nerves.
• Reproductive system: in humans and other organisms, gamete formation and reproduction takes place by the reproductive system. It includes the sex organs of males and females.
Classification of Systems
The system used to classify organisms is called a classification system. It includes several procedures, characteristics, and definitions, which are used to classify organisms. Carl Woese classified all the living things into three major groups or domains: the archaea, the eubacteria, and the Eucarya.
The organisms are classified into various taxonomic groups such as kingdom, phyla, class, order, family, genus, and Species. The classification of organisms has been studied under the branch of biology named taxonomy. The archaea and eubacteria include the prokaryotic organisms.
All eukaryotic organisms belong to the domain eukarya. These organisms have a prominent nucleus and other membrane-bound organelles including endoplasmic reticulum, mitochondria, Golgi apparatus, etc. the eukaryotic organisms are further classified into Protista, fungi, plants, and animals.
Protists include unicellular or multicellular organisms including algae, slime molds, etc. Fungi are unicellular organisms that are made up of mycelium. All human beings belong to an animal group whereas Plantae includes all plants that can perform photosynthesis.
- A guide to ecosystem models and their environmental applications. Nat Ecol Evol . 2020 Nov;4(11):1459-1471.
- When Do Ecosystem Services Depend on Rare Species? Trends Ecol Evol . 2019 Aug;34(8):746-758.
- An Overview of Drug Delivery Systems. Methods Mol Biol . 2020;2059:1-54.
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