The creation of new varieties of cultivated plants combines a wide variety of selection methods. The main importance in the selection of cultivated plants belongs to mutations, spontaneous and artificial hybridization between different species and polyploids. Especially widely used in plant breeding is polyploidy. Most cultivated plants on Earth are polyploids. Basically, the same methods are used in the selection of microorganisms as in the selection of other organisms. But the microscopic dimensions and the enormous growth rate of microorganisms determine the development of special methods that accelerate the process of obtaining new highly productive strains. These methods include genetic engineering and biotechnology.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.