Technology of storage and primary processing of agricultural products

Physiological-biochemical criteria - all the processes in the life of each species, indicating the individuality of the chemical composition. In particular, the physiological criteria are based on the similarity of all life processes of a species of individual, primarily the method of reproduction. Representatives of different species usually do not mix with each other, the main reason for their lack of mixing is the difference in the structure of the penis and the different reproduction periods. From a biochemical point of view, the study of the DNA properties of a species is of particular importance in the biochemical evaluation of a species. It is known that the ratio of DNA nucleotides (G + Ts) (A + T) varies in different groups of animals and plants. At the same time, there is a regularity in this regard, that is, the variability decreases as the evolutionary process moves from the older systematic groups to the younger ones. However, in vertebrates, the DNA content is less variable, while invertebrates, the DNA content is more variable.
Genetic criteria are the main criteria of a species. The genetic criterion is the set of chromosomes that are unique to each species, their exact number, size, and shape. Individuals of different species have different sets of chromosomes, so they cannot mix with each other under natural conditions and are limited from each other.
Ecological-geographical criterion is based on the determination of the laws of geographical distribution of the studied species and its interaction with environmental factors of the external environment. An environmental factor is a set of environmental factors in which a species lives. For example: Poisonous reptile is common in meadows, reptile reptile grows in slightly wet areas, reptile reptile grows in rivers, ponds and swamps, saxaul grows in sandy deserts, and so on. A geographical criterion is a specific area that a species occupies in nature. This area can be large or small, ring-shaped or monolithic. Species with separate habitats are called A llopatric species , while species with adjoining or integral areas are called sympatric species .