Think of a classroom. There may be a computer, a plant, some artistic materials and the teacher. Which one of them is considered alive? Both the plant and the teacher are alive.
For the purposes of science, it is important to distinguish what makes something alive from what is not. Both the plant and the teacher are considered organisms.
Any living being is considered an organism. All living organisms share several key features or functions, including order, nutrition, response to stimuli, reproduction, growth/development and homeostasis.
An organism is defined as anything alive. This ranges from the most microscopic bacteria to the large blue whale and everything in the middle.
According to scientists, there are approximately 8.7 million species on our planet, with about 80% of the species yet to be discovered.
Characteristics of the organism
All living organisms share several key features or functions:
Organisms are extremely organized structures consisting of one or more cells. Even single-celled organisms can be quite complex.
Organisms take materials from their environment to gain energy or to grow.
Response to stimuli
Organisms are able to perceive and respond to the stimuli around them. For example, microorganisms may approach or move away from a chemical.
Organisms have the capacity to produce offspring, through asexual or sexual reproduction.
A single parent participates in asexual reproduction and produces one offspring genetically identical to the other.
Sexual reproduction involves two parents and produces a seed that is genetically unique.
Growth and development
All organisms grow and develop according to the specific directions encoded in their genes. This code is the one that directs growth and cell development, which guarantees that the offspring of the species will grow showing many of the same characteristics as its parents.
Homeostasis is the ability of an organism to maintain constant internal conditions. By maintaining homeostasis, an organism is able to function optimally.
History of the organism
The Earth today is dramatically different from what was millions or even billions of years ago. The early Earth had limited amounts of oxygen and high levels of methane in its atmosphere.
This environment was not conducive to the growth of agencies. The first known organisms were microbes (microscopic organisms), which lived about 3.7 billion years ago. As the Earth changed, more life appeared.
- 3.5 billion years ago – evidence of microbes preserved in stromatons (hard and stratified mounds of photosynthetic cyanobacteries)
- 2.4 billion years ago – Cyanobacteria becomes the first photosintetizers of the Earth (use water, carbon dioxide and the energy of the Sun to produce oxygen and glucose).
This sudden increase in oxygen made Earth less friendly to microbes that did not tolerate oxygen. During this time, there were other processes.
Microbes began to live within other microbes, which ended up becoming the functional or functional organelles (organized or specialized structures within a cell).
- 800 million years ago – Specialist cell groups ended up becoming the first animals, which were sponges.
- 580 million years ago (Ediacaran period) there was an explosion of other organisms that lived with the sponges for 80 million years.
At the end of this period, oxygen levels rose to levels sufficient to sustain oxygen-based life.
- 541 million years ago, most of the ediacaran organisms disappeared, which could have been due to environmental changes.
- 541-485 million years ago (the Cambrian period) in this period there was another explosion of new ways of life.
Several organisms were developed with hard body parts, active lifestyles, defined heads and tails and active feeding.
At the end of the Cambrian period, almost all types of animals today were established and food networks began to emerge that began to form the foundations of the ecosystems we see today.
- 485 million years ago – today – organisms have continued to evolve and become extinct to give us the current group of species on our planet.
As environmental conditions change, organisms evolve to survive or begin to become extinct if they cannot adapt to Earth’s conditions.
Scientists in the field of biology are responsible for studying organisms and their environment.