What is Classification?

 

Biological classification is essentially the process by which scientists group and divide living organisms based on shared characteristics. Organisms divided each respective group then become further divided, or specific, into groups with less organisms. These are divided into 7 groups according to similarities, number one being the broadest and most general characteristics and species being the most specific. [23]

 

All living organisms are classified into groups These smaller groups, such as family, genus and species, are based on more specific similarities within each larger group, with characteristics such as but not limited to: physical appearance, reproduction, mobility, and functionality. This classification - or taxonomic system - makes it easier for people to study certain groups of organisms. [20] 

 

The levels of classification of living things includes 7 levels: kingdom, phylum, classes, order, families, genus, and species .

 

1. Kingdom:

 

The most basic and generic classification is Kingdom. Living things are placed into certain kingdoms based on how they obtain their food, the types of cells that make up their body, and the number of cells they contain. [23]

 

5 Kingdoms:

1. 1. Monera (includes Archaea/Archaeabacteria, and Bacteria/Eubacteria)

• Examples: bacteria, cyanobacteria or blue-green algae

• Absorption of food through the cell wall, chemosynthesis and photosynthesis

• Number of Species Identified: 4,000 - 10,000 [24] 

•  

1. 2. Protista

• Protozoans, slime molds and some unicellular algae

• Absorption, ingestion and photosynthesis.

• Number of Species Identified: 80,000 [24] 

 

1. 3. Fungi

• Molds, yeasts, mildews, smuts, toadstools and mushrooms.

• Number of Species Identified: 70,000 - 72,000

• Absorption of nutrients from dead and decaying organic materials [24] 

 

1. 4. Plantae

• Algae, mosses, ferns, flowering plants and non-flowering plants

• Number of Species Identified: 270,000

• Mode of Nutrition: Photosynthesis [24] 

1.  

2. 5. Animalia

• Organisms: Sponges, insects, worms, fish, reptiles, amphibians, birds and mammals

• Number of Species Identified: 1,326,239 - 1,500,000

• Feeding on other organism [24] 

 

 

2. Phylum:

 

Phylum is the next level following kingdom in the classification of living things. It serves to find physical similarities among organisms within a kingdom; these suggest that there is a common ancestry between those organisms in the phylum. [23]

 

Chordata:

 

The phylum Chordata contains all of the vertebrate animals that exist, as well as a few of the invertebrate ones. Though all members of this phylum have certain common structures, these can be present forever or go away as it leaves the embryo stage. [25] 

 

These structures include haryngeal slits, which could be used as gills; these are essentially openings in the throat that connect to the neck of the organism. Though gills are present in other chordates, it is notably a feature of fish. [25]

 

Another common characteristic of chordates is the presence of a dorsal nerve cord; this is a bundle of nerve fibers that runs down the top of the animal, connecting it to the brain with the muscles and other organs. [25]

 

The third characteristic present in members of the Chordata Phylum is a notochord, rod running underneath the skin which supports the nerve cord. [25]

 

Lastly, the fourth characteristic present in members of the Chordata Phylum is a post-anal tail. This is an extension of the body past the anal opening. [25]

 

An example of a Chordate is the adorable Sea Otter- click on the "About Sea Otters" tab to explore more about this fascinating Chordate!

 

3. Class: 

 

Classes have the taxonomic function of further dividing organisms of a phylum.  Organisms within a class have even more in common than those in an entire phylum; for example, humans belong to the Mammal Class because we drink milk as a baby. [25]

 

Since there are over 100 classes of animals, I picked class the 5 most well known classes of animals and analyzed them in detail- these are all vertebrates from the phylum Chordata: Class Amphibia, Reptilia, Osteichthyes, Aves and Mammalia.

 

Click on the tab "Phylum Chordata" to find out more on each of these interesting classes!

 

 

4. Order: 

Organisms in each class are further grouped into orders. Taxonomy keys, devices used by biologists to unknown organisms that are similar to a checklist of characteristics, serve to determine to which order an organism belongs.

Since there are hundreds of orders in the animal kingdom alone, the most common orders have been chosen and researched! [23] 

 

1. In Class Mammalia:

Didelphimorphia Order:

This order includes opossums, and includes 103 or more species in 19 genera. The females, similarly to other marsupials (like the kangaroo!) have a pouch to carry their young. [26]

Did you know…?

 

1. Opossums are mostly immune to rabies, a deadly virus spread to people from the saliva of infected animals, and also possess partial or total immunity to the venom produced by rattlesnakes, cottonmouths and other pit vipers.

2. The opossum has opposable thumbs (or toes, because they are located on its rear feet), responsible for the opossum’s great climbing skills. We take opposable thumbs for granted, but in fact primates and opossums are the only mammals with opposable first toes.

3. The opossum has a beautiful smile, with an impressive 50 teeth. [27]

 

2. In Class Aves:

Strigiformes Order:

This order includes owls, with about 200 species in the order! [18] 

Did you know…?

1. Owls can rotate their necks 270 degrees. [29]

2. Owls are nocturnal animals, making its easy for them to find their preys (insects, small mammals and other birds) as they sleep. In addition, the color of their feathers helps them blend into their environment (camouflage), which helps them to hide from their preys and predators. Furthermore, owls are farsighted, which helps them catch their preys easily when they are perched on a tree. 

3. A group of owls is called a parliament. [28]

 

3. In Class Amphibia:

Caudata Order:

Caudates make up around 9% of the world's amphibian species and contains 9 families and 600 species. [30] 

 

Newts are salamanders, however, salamanders are not always newts. This is because the word "salamander" is the generic name for the scientific order of amphibians that have tails as adults - caudates. [31]

Both salamanders and newts are amphibians, and have from eggs that are laid near or in water. Most of them have gills when born, but these eventually develop into lungs - however, some have both gills and lungs forever. On the flip side, some salamanders have neither lungs nor gills - these breathe through the skin in their mouths. [32]

 

Did you know…?

 

Some salamanders are amphibious, others terrestrial, others entirely aquatic.

1. Salamanders can lay up to 450 eggs at once.

2. Salamanders and newts are carnivores. They move slowly so they have to catch slow-moving prey like worms or snails.

3. Usually, salamanders grow to be between 2 and 6 inches long. However, giant salamanders can grow 6 feet long - this is taller than you! [32]

 

4. In Class Reptilia:

Testudines Order:

It is the order that includes turtles and tortoises. These have a hard shell, which is their ribs. All turtles bury their eggs, do not have teeth and have three-chambered hearts. Some testudines hibernate and can live order 150 years. [33]

 

Did you know…?

 

Their shells are made up of over 60 bones, the upper section being the carape and the lower section the plastron

Even turtles that spend most of their time underwater must come to the surface regularly in order to breathe.

Their shells are used to store minerals such as Calcium. [33] 

 

5. In Class Osteichthyes:

Siluriformes Order: Includes Catfish.

3000 species of catfish can be found everyone in the world except for Antarctica.

They are freshwater fish, but some adapt to salt waters and caves. [49]

 

Did you know…?

While the smallest species of catfish, called banjo catfish, is only 0.39 inches long, the largest species, Mekong catfish, can reach nearly 9 feet in length and 646 pounds in weight, and usually live between 8 and 20 years.

The name "catfish" was given to this species due to their cat-like whiskers. [49] 

 

An average adult measures 12 to 24 inches (31 to 61 cm) and weighs two to seven pounds (1 to 3 kg); these can live up to 25 years. 

Though the diet of catfish consits of a wide array of organisms, larvae, crayfish, mollusks, small fish and clams, snails, worms and seeds are the main foods on their menu. 

In fact, since catfish mainly feed at night, they use their whiskers to identify food in the deep, dark water. [34]

 

5. Families

 

Orders are further divided into families. Organisms within a family have more in common than with organisms in any classification level above it, hence, these organisms are said to be related to each other. [23]

 

There are hundreds of families of living things, but a few of them have been researched for you!

 

1. Hominidae

Well… guess who is classified as an Hominidae? You and I! Humans are Hominidae, which is the family of the Great apes or Hominids. As you know, since the beginning of time (billions of years ago), humans have been evolving into what they are today… however, we did not always look the way we look like, think the things we think or act the way we act. We have evolved from the Apes - in fact, our closest relatives are the chimpanzees, gorillas, and orangutans. [51]

 

Now… you might be wondering about the difference between primates and monkeys, and why we are not a monkey…

The main difference is: monkeys possess tails, and primates do not. Since we do not possess a tail, we are primates. Simple as that! Now, there are a few exceptions… but that is the general rule! [50]

 

2. Cannabaceae

The second family is the Cannabaceae family, in the Plantae Kingdom.

There are 8 genera in the family Cannabaceae, including Angiosperms (Flowering plants).

One of the genera is Cannabis - yes, Marijuana. [52] 

 

 

6. Genus

 

Genus is a way to describe the generic name for an organism - it is the first word of the two word scientific name. The genus classification is very specific and, for this reason, there are few organisms within each one. Thus, there are many genera of plants and animals, especially. [23] 

 

Eucalyptus:

The size of the eucalyptus depends on the species, but the trees can reach 33 to 200 feet in height. Their leaves of eucalyptus have lanceolate shape that face downwards as to prevent direct exposure to the sunlight, which could cause loss of water. [35]

 

Did you know…?

The fruit of the eucalyptus is called gum nut.

Eucalyptus trees usually live for 250 years in the wild.

Leaves of eucalyptus are rich in oil that is used to alleviate symptoms of bronchitis, sore throat, nasal congestion… you have most likely used a eucalyptus based medicine several times in your life! [35]

 

 

7. Species

 

And finally… species are as specific as you can get. It is the lowest and most strict level of classification of living things, the main criterion being the species' ability to breed with other organisms of that same species and produce fertile offspring. The species of an organism determines the second part of its two-part name. [23] 

 

Example:  Ornithorhynchus anatinus

One of the most unusual creatures in the animal kingdom, the platypus is venomous, egg-laying mammal, mainly present in certain parts of Australia, notably Tasmania. They have waterproof fur, skin that covers their ears and eyes, and noses that seal shut to protect the animals while they are underwater. They are usually around 3.3 feet long (½ meter). One of their most famous characteristics is their bill, which is flexible and rubbery. [36] 

 

Did you know…?

Platypuses swim with their front feet and steer with their tails and back feet. Though platypuses are made for the water, they can't stay completely submerged. They can only stay underwater for 30 to 140 seconds.

Platypus' skeletons resemble those of reptiles. They both have pectoral girdles and splayed legs. [36]

 

Classification is FUN!

Let's classify you and me!

 

Domain: Eukaryota

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hominidae

Genus: Homo

Species: H sapiens [53] 

 

So, we can each other the Homo sapiens! 

Remember: the first word is always capitalized, and the second is lowercase.

 

 

 

 

 

 

 

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