fungus
Heterotrophs with eukaryotic cells and cell walls. There are many species and genera, with 654.38+100,000 reported genera and 654.38+100,000 species. Except for a few lower types of single cells, most of its vegetative bodies are composed of slender tubular mycelium. The hyphae of lower fungi have no septa, while those of higher fungi have septa. The former is called partition, and the latter is called partition. In the cell walls of most fungi, chitin is the most characteristic, followed by cellulose. Common fungal organelles are: nucleus, mitochondria, microbodies, ribosomes, vacuoles, lysosomes, vesicles, endoplasmic reticulum, microtubules, flagella and so on. Common inclusion bodies are glycogen, crystals, liposomes and so on.
Fungi are usually divided into three categories, namely, yeast, mold and mushroom (large fungi), belonging to different subphylum.
Macrofungi refer to fruiting bodies or sclerotia that can form fleshy or gelatinous substances, most of which belong to Basidiomycotina, and a few belong to Ascomycota. Common macrofungi are Lentinus edodes, Volvariella volvacea, Flammulina velutipes, Agaricus bisporus, Pleurotus ostreatus, Auricularia, Tremella, Dictyophora, Morchella and so on. They are not only important fungi and vegetables, but also important resources for food and pharmaceutical industries.
gemmule
Belonging to the category of biology, it is a kind of prokaryote with short body and simple structure, and it is mostly propagated by dichotomy. It is the most widely distributed creature with the largest number of individuals in nature, and it is the main participant in the material cycle of nature. Bacteria are mainly composed of cell wall, cell membrane, cytoplasm and nucleosome, and some bacteria also have special structures such as membrane, flagella and fimbriae. Most bacteria are between 0.5 and 5 μ m in diameter and can be divided into three types according to their shapes, namely, cocci, bacilli and spirochetes (including arc bacteria). There is also a method to classify bacteria, which can be divided into saprophytes, parasites and autotrophs.
virus
It is a kind of acellular microorganism, with tiny individual, no complete cell structure and single type of nucleic acid (DNA or RNA), which must be parasitic in living cells for replication.
Originally refers to toxins of animal origin. The word "virus" comes from Latin. Viruses can proliferate, inherit and evolve, so they have the most basic characteristics of life. Its main features are as follows: ① The genome containing a single nucleic acid (DNA or RNA) and the protein shell have no cell structure; (2) Release the nucleic acid of infected cells at the same time or later, and then proliferate in the form of nucleic acid replication instead of binary division; ③ Strict intracellular parasitism.
Since the 1940s, viruses have been important materials in molecular biology research because of their simple structure and components, and some viruses are easy to be cultured and quantified.
In practice, virus research has made important contributions to the prevention and treatment of human, plant and animal diseases. Such as developing virus vaccines and using insect viruses as pesticides. In 1982, viruses with complete data and classification are divided into 7 groups: (double-stranded) enveloped ds DNA (double-stranded) ds DNA, without envelope; (single-stranded) ss DNA, without envelope; Encapsulated (double-stranded) ds RNA (double-stranded) ds RNA, without encapsulation; Encapsulated (single-stranded) ss RNA (single-stranded) ss RNA, uncoated.
The word "virus" comes from Latin and originally refers to a toxin of animal origin. Virus can reproduce, inherit and evolve, so it has the most basic characteristics of life, but there is no accepted definition so far. At first, it was used to identify the characteristics of viruses, such as tiny individuals, which can't be seen under the optical microscope, can pass through filters that bacteria can't pass through, can't grow on artificial media, and are pathogenic. And it is still of practical significance. But in essence, the virus is different from other organisms in the following characteristics: ① The genome containing a single nucleic acid (DNA or RNA) and the protein shell have no cell structure; (2) Release the nucleic acid of infected cells at the same time or later, and then proliferate in the form of nucleic acid replication instead of binary division; ③ Strict intracellular parasitism. The virus lacks independent metabolic ability, so it can only replicate its nucleic acid in living host cells and synthesize protein encoded by its nucleic acid, and finally assemble into a complete and infectious virus unit, that is, virus particles. Virus particles are the main form of virus transmission between cells or hosts.
At present, the meaning of the word virus can be: refers to those microorganisms or genetic units with unique chemical composition and proliferation mode, which can only be replicated in host cells. It is characterized by containing only one type of nucleic acid (DNA or RNA) as the carrier of genetic information; Does not contain functional ribosomes or other organelles; RNA virus, all genetic information is encoded on RNA, which is unique in biology; It is much smaller than bacteria and contains only a few enzymes. It can't proliferate in inanimate media, and it must rely on the metabolic system of the host cell to replicate its own nucleic acid, synthesize protein and assemble it into complete virus particles, or virions (complete virus particles refer to mature virus individuals).