The name of the science of biology was given in 1802 by the French scientist Lamarck. At that time, she was still beginning her development. And what does modern biology study?
Sections of biology and what they study
In a general sense, biology studies the living world of the Earth. Depending on what modern biology studies specifically, it is divided into several sections:
- molecular biology is the study of living organisms at the molecular level;
- section of biology that studies living cells - cytology or cytogenetics;
- living organisms - morphology, physiology;
- biosphere at the level of populations and ecosystems is studied by ecology;
- genes, hereditary variability - genetics;
- embryo development - embryology;
- evolutionary biology and paleobiology deals with the theory of evolution and the oldest organisms;
- ethology studies the behavior of animals;
- general biology - processes common to the whole living world.
There are also many sciences involved in the study of certain taxa. What is thisbranches of biology and what do they study? Depending on which kingdoms of living organisms studies biology, it is divided into bacteriology, zoology, mycology. Smaller taxonomic units are also studied by separate sciences, such as entomology, ornithology, and so on. If biology studies plants, then the science is called botany. Let's take a closer look.
What kingdoms of living organisms does biology study?
According to the currently prevailing theory, the living world has a complex structure and is divided into groups of different sizes - taxa. The classification of the living world is de alt with by systematics, which is part of biology. If you need an answer to the question of which kingdoms of living organisms studies biology, you need to turn to this science.
The largest taxon is an empire, and the living world consists of two empires - non-cellular (another name is viruses) and cellular.
From the name it is clear that the members of the first taxon did not reach the cellular level of organization. Viruses can reproduce only in the cells of another, cellular, organism - the host. The structure of viruses is so primitive that some scientists do not even consider them alive.
Cellular organisms are divided into several superkingdoms - eukaryotes (nuclear) and prokaryotes (pre-nuclear). The former have a well-formed cell nucleus with a nuclear membrane, the latter do not have it. In turn, overkingdoms are divided into kingdoms.
The kingdom of eukaryotes consists of three kingdoms of multicellular - animals, plants and fungi, and one kingdom of unicellular - protozoa. The kingdom of protozoa includes many heterogeneous organisms that have great differences. Sometimes scientists divide protozoa into several groups, depending on the type of food and other features.
Prokaryotes are usually divided into the kingdoms of bacteria and archaea.
Currently, scientists propose a different division of wildlife. Based on the signs, genetic information and differences in the structure of cells, three domains are distinguished:
- archaea;
- real bacteria;
- eukaryotes, in turn dividing into kingdoms.
What kingdoms of living organisms does biology study today:
Domain or kingdom of archaea
Prokaryotic microorganisms live in the oceans, soil, human intestines (involved in the process of digestion), extreme environments such as hot springs and other places. Prokaryotic cells do not have a nucleus and membrane organelles. Unlike bacteria, no archaea are known to lead a parasitic lifestyle; they also cannot be considered pathogenic, although there are studies indicating the connection of archaea with periodontitis. All representatives of the same species of archaea have identical genetic material, since they do not have meiosis - they reproduce asexually. Do not form a dispute, unlike other domains. They have a unique genome, different from eukaryotes and bacteria.
Kingdom (domain) of bacteria or eubacteria
Prokaryotes are usually unicellular, but sometimes form colonies (cyanobacteria, actinomycetes). They do not have a nucleus enclosed in a membrane, andmembrane organelles. A bacterial cell contains a nucleoid that is not shaped into a nucleus and contains genetic information. The cell wall consists mainly of murein, although some bacteria lack it (mycoplasmas). Most bacteria are heterotrophs, meaning they feed on organic matter. But there are also autotrophs, for example, capable of photosynthesis - cyanobacteria, which are also called blue-green algae.
Some bacteria are useful - contained in the intestinal microflora are involved in digestion; some are harmful (causative agents of infectious diseases). People have long been able to use bacteria for their own purposes: for the production of food, medicines, fertilizers and so on.
Kingdom of Protozoa
Includes all eukaryotes other than animals, plants and fungi. This includes directly protozoa with a heterotrophic type of nutrition, algae, fungi-like protozoa. Usually protists are single-celled, but are often capable of forming colonies. They usually live in liquid or wet environments. Eukaryotic cells have a nucleus and membranes. Reproduction is both sexual and asexual. There are protozoan parasites of humans, animals and plants that cause various diseases (dysentery, malaria, and others). At the same time, some types of protists are useful, forming deposits of limestone or performing the function of orderlies in reservoirs.
Mushroom Kingdom
Eukaryotic organisms with a heterotrophic type of nutrition. Cells have one ormultiple cores. The cell wall contains chitin. Characterized by symbiosis with higher plants and the formation of mycorrhiza. They reproduce by spores. The ability for unlimited growth and immobility in the vegetative phase make fungi related to plants. The body of the fungus consists of hyphae - long threads. Mushrooms are useful, like those that people eat (departments of ascomycetes, basinomycetes). But many types of fungi are parasites or pathogens that cause diseases in humans, animals and plants that damage food. Some types of mushrooms, such as yeast or penicillin, are used by people for their own purposes.
Plant Kingdom
Eukaryotes; distinctive features - the ability to unlimited growth, autotrophic type of nutrition (photosynthesis), a fixed lifestyle. Cellulose cell wall. Reproduction is sexual. They are divided into sub-kingdoms of lower and higher plants. Lower plants (algae), unlike higher plants (spore and seed plants), do not have organs and tissues.
Animal Kingdom
Eukaryotic multicellular organisms with a heterotrophic type of nutrition. Features - limited growth, ability to move. Cells form tissues; cell wall is absent. Reproduction is sexual; in lower groups, alternation of sexual and asexual is possible. Animals have nervous systems of varying degrees of development.
