Classification of Organisms. How many different types of organisms

Different Types of organisms

Types / October 31, 2016

What is an Organism?

Simply put, an organism is a form of life. Whether it be an animal, plant, fungus, protistan, moneran. Or bacterium. Organisms can consist of one or more cells and are all able to respond to stimuli, reproduction, growth and development, and homeostasis.

It is estimated that there are currently 10 million to 14 million different species living on planet Earth, although only a fraction of them have been documented. It is believed that over five billion species from the beginning of time, are now extinct.

There are several different types of organisms, including: producers, scavengers, parasites, consumers, predators, carnivores, omnivores, herbivores and decomposers.

  1. Producers make their own food using the sun. In almost all cases, these organisms consist of plants and other unicellular organisms. For instance, plants experience the process of photosynthesis to make food.
  2. Scavengers are organisms that find and eat dead animals. They play an important part in our ecosystem as they clean up other animals' messes. For instance, when leopards are unsuccessful at catching their prey, they will often scavenge. Raccoons will go through your garbage in hopes of finding leftover scraps as well.
  3. Parasites live on or in another organism and feed on them. A parasite can cause damage and/or eventually kill the organism it is feeding on. Tapeworms and fleas are considered parasites, for example. If a parasite infects a human body, it is often caused by drinking dirty water or eating spoiled food.
  4. Consumer organisms eat plants or other animals. They can be considered carnivores, omnivores or herbivores, or in other words, primary, secondary or tertiary consumers, which we talk about in more detail below.
  5. Predators find their own food from plants or other animals, which would be known as their prey. For instance, a good example of a predator/prey relationship would be a bear and a fish. Several animals are predators in one way or another; however, there are some animals that don't have any predators to worry about, such as tigers and the Saltwater Crocodile.
  6. Carnivores only eat, hunt and kill other animals for food. Carnivores range from something as small as a ladybug to sharks and lions. There are two types of carnivores: obligate and facultative. Obligate carnivores rely solely on meat, while facultative carnivores eat non-animal food in addition to animal flesh to obtain nutrients.
  7. Omnivores eat both plants and animals. Omnivores may be limited to what they can and cannot eat, although the true meaning of the word is 'eater of everything.' Omnivores range from something as small as cockroaches and crayfish to humans and chickens. Even some bears are considered omnivores!
  8. Herbivores only consume plant material. Deer, caterpillars and some bird species are great examples of herbivores. Herbivores must have digestive systems that run like well-oiled machines, in order to digest large amounts of plant-based food successfully. Animals rely solely on plants' fiber and starch for nutrients.
  9. Decomposers obtain energy by breaking down dead plants and animals. Decomposers are organisms such as bacteria or fungi.

Our Ecosystem

These different types of organisms make up, what is called, our ecosystem. Each of the above organisms rely on one another, as well as the environment they live in, to sustain themselves. This community of living organisms, in conjunction with energy, air, water, nitrogen, minerals etc., become a system…our ecosystem. Linked together through nutrient cycles and energy flows, the organisms within the ecosystem interact with one another, starting at one end of the spectrum and helping sustain all different types of organisms.

The Cell Theory

Founded in 1839, by Matthias Jakob Schleiden, Theodor Schwann and Rudolf Virchow, the cell theory states that all organisms are composed of one or more cell. Keeping that in mind, organisms are classified by either being unicellular or multicellular and therefore prokaryote or eukaryote.

  1. Organisms are known as unicellular when they have only one cell. Most unicellular organisms are microscopic in size. With that being said, they are often referred to as microorganisms.
  2. Organisms are known as multicellular when they are made up of multiple cells. Humans, for instance, are considered multicellular organisms, as they are made up of trillions of different cells.
  3. Prokaryotes are unicellular organisms and are divided into two different domains: bacteria and archaea. These cells do not have a nuclear membrane.
  4. Eukaryotes are organisms with nuclei and organelles, like mitochondria in animals and plants, and plastids in plants and algae. Fungi, animals, and plants are all considered to be eukaryotes.
  5. All cells, whether prokaryote or eukaryote, are made up the same. They all have a membrane, which contains a cytoplasm (making up for the majority of the cell's volume), envelops the cell and ultimately protects the interior of the cell from the outside environment. They each contain biomolecules, like proteins and nucleic acids. Although cells are quite complex, most are only visible when using a microscope, coming in at anywhere between 1 and 100 micrometers.
  6. Characteristics of cells

    . All cells, no matter their makeup, share similar characteristics or reproduction, metabolism, their response to stimuli and their use of enzymes and other proteins.

How Organisms Relate to Chemistry

Based on the information above, there's no doubting the fact that organisms are complex. Each type of organism has a place in our ecosystem. Organisms, no matter the type, are extensive systems made up of chemical compounds that are responsible for many things in their environment. Although organisms are their own individual organisms, they are constantly having to rely on other organisms to survive. They take in and release energy as needed.