A person tends to systematize the objects of the surrounding world in order to generalize, which is convenient when talking. So, even in everyday life, for example, we generalize the objects used in the preparation and consumption of food. We call this category "dishes". The word “furniture” is constantly used in everyday life, which includes a table, a bed, and a closet.
System in biology
The biosphere includes a huge number of species of living organisms. For the convenience of communication of all people, and especially biologists, scientists have identified systematic categories of different ranks. It turned out a whole system of living organisms. Because living nature is not just objects, but organisms that are related to each other. According to the theory of evolution, all living things originated from a single cell. That is, among living organisms there are close and distant relatives. Species close to each other are included in the general systematic category and constitute a taxonomic group of living organisms in it.
In the course of the development of biology, a whole science was formed that deals with the systematization of living beings. It's calledsystematics. Systematics distinguishes taxonomic groups of living organisms, which are combined by similarity. They are also related to each other. That is, a taxonomic group is organisms related to each other, which are usually similar in appearance, in physiological characteristics and at the genetic level.
Ranks of systematic categories
Taxonomic groups in biology have a hierarchy:
- The basic unit of taxonomy is the species. When naming an animal, we usually mean the type of organism. Animals of the same species can produce offspring. Different types of living beings in nature usually do not interbreed and do not give offspring. Therefore, each species is well distinguished from the others.
- Next in the hierarchy is a systematic category called "kind". This taxonomic group includes species that are related to each other, that is, descended from one common ancestor.
- Family is the next category of the system of flora and fauna. The family includes related genera of living organisms.
- An order includes one or more families presumably descended from a common ancestor.
- The taxonomic group of animals of the "class" category includes one or more orders.
- Kingdom is a collection of related units of living organisms.
Kingdoms of wildlife
All living organisms are divided by scientists into 8 kingdoms:
- Animals.
- Plants.
- Mushrooms.
- Bacteria.
- Viruses.
- Protists.
- Archaea.
- Chromists.
What is a "domain"?
In turn, kingdoms are referred to as domains. Domain is the highest systematic category. Total domains 4:
- Eukaryotes.
- Bacteria.
- Archaea.
- Viruses.
Number of species in taxa
Thus, taxonomic groups in the world of animals, as well as plants and other organisms, differ greatly in the number of species included in them. For example, the systematic category "genus" can include both one and several dozen species. One family may include one genus, two genera, or many more. There are families that include several thousand species.
Plant Systematics
The taxonomic categories of the plant kingdom are somewhat different from the taxonomic groups of the animal kingdom.
The lower rank after the realm is "department". 15 or 16 divisions of plants are allocated, depending on the taxonomy belonging to one or another scientist. This is followed by Class - Order - Family - Genus - Species. "Order" in the plant system corresponds to "order" in the animal kingdom. The category "department" corresponds to the category "type".
An example of a system in the plant world
Aspen belongs to the poplar genus, the willow family, the order of willows, the dicotyledonous class, to the department of flowering plants, the plant kingdom, the eukaryotic domain. Aspen in the scientific language is also called "trembling poplar".
Species name most often consists of two words, the first of which is the generic name, andthe second is view.
Latin in Biology
In biology, the Latin language is widely used to understand natural objects by scientists around the world. Scientists know the Latin names of species of living organisms by heart or can check them from books. In the scientific literature, next to the Russian name there is always a name in Latin.
Plant varieties, breeds and subspecies of animals
Cultivated plants often have multiple varieties within a variety. A domestic apple tree, for example, has several thousand of them.
Varieties are bred by people using the selection method. Unlike species, varieties cross easily with each other.
People are breeding new breeds of domesticated animals. Breed more egg-laying hens, meat breeds of pigs, more dairy cows and so on. New breeds of cats and dogs delight their owners.
Where do many subspecies of animals come from? Many species of animals have spread widely over the earth. Gradually evolving, populations change both in appearance and lifestyle. Subspecies are formed that can still produce common offspring.
Thus, taxonomic groups in biology have a different number of their constituent species or subspecies of living organisms. The higher the rank, the more species it covers.
