Biology – what is it? It is the study of life, in all its splendor. From the smallest algae to the largest elephant, biology encompasses all life forms. But how do we know if something is alive? Is a virus alive or dead, for example? Biologists have developed a set of criteria known as “life characteristics” to answer these questions.
A living thing includes both the visible world of animals, plants, and fungi, as well as the invisible world of bacteria and viruses. On a fundamental level, life is ordered. The organization of organisms is enormously complex. Cells are the basic unit of life, and we are all familiar with their intricate systems.
Life can work. No, that does not mean all animals can work. Living creatures can absorb energy from their environment. Energy is converted into food in order to maintain metabolic processes and to survive.
As life develops, it grows. In other words, it means more than just replicating or growing larger. When injured, living organisms can also rebuild and repair themselves.
It is possible for life to reproduce. Have you ever seen filth breed? I don’t think so. Life can only come from other living creatures.
Life may respond. Think back to the last time you accidentally touched your toe. Almost instantaneously, you have retreated into pain. This response to stimulation characterises life.
Lastly, life can adapt and respond to the requirements of the environment. There are three fundamental types of adaptations that can happen in higher organisms.
- Reversible changes happen as a result of changes in the environment. Let’s say you live close to sea level and go into a mountainous region. You may begin to have difficulty breathing and an increase in heart rate because of the change in altitude. These symptoms disappear when one descends to sea level.
- Somatic changes take place due to prolonged changes in the environment. Using the previous example, if you were to stay in the mountainous area for a long time, you would notice that your heart rate would begin to slow down and you would begin to breath normally. Somatic changes are reversible as well.
- The latter is referred to as genotypic adjustment (caused by a genetic mutation). These changes occur in the body’s genetic composition and are irreversible. One example is pesticide resistance among insects and spiders.
In short, life takes shape, “works”, grows, reproduces, responds to stimuli and adapts. These characteristics serve as the foundation for the study of biology.
Biology’s Fundamental Principles
The foundation of modern biology is built on five fundamental principles. Cell theory, gene theory, evolution, homeostasis, and thermodynamic laws are examples.
Cell Theory: Cells make up all living organisms. The cell is the fundamental unit of life.
Gene Theory: Gene transmission is how traits are passed down. Genes are DNA structures found on chromosomes.
Evolution: any genetic change in a population that is passed down through generations. These modifications can be small or large, noticeable or not.
Homeostasis: ability to maintain a constant internal environment in response to changes in the environment
Thermodynamics: Energy is constant, and energy transformation is inefficient.
Biology is a very broad field that can be divided into several disciplines. In the broadest sense, these disciplines are classified according to the type of organism studied. For example, zoology is the study of animals, botany is the study of plants, and microbiology is the study of microorganisms. These areas of study can be further subdivided into several specialised sub-disciplines. Anatomy, cell biology, genetics, and physiology are a few examples.