The hybridological method is a system of crosses that allows tracing the patterns of inheritance of traits in a number of generations.
Distinctive features of the method:
- purposeful selection of parents differing in one, two, three, etc. pairs of alternative signs;
- strict quantitative accounting of the inheritance of traits in hybrids;
- individual assessment of offspring from each parent in a series of generations.
Genealogical method – drawing up a pedigree and analyzing it.
Pedigree analysis is used for organisms that cannot interbreed (humans) or reproduce slowly.
Using this method, you can establish the features of the inheritance of traits. If a trait appears in every generation, then it is dominant; if the trait manifests itself after a generation, then it is recessive. If a trait is more often manifested in one sex, then it is a sex-linked trait.
The twin method is the study of the manifestation of signs in identical and fraternal twins.
The twin method allows one to study the role of genotype and environment in the formation of specific characteristics of an organism. Identical twins have the same genotype, so they are always the same sex and look alike. The differences that occur in these twins during life are associated with the impact of environmental conditions.
Population-statistical method – analysis of the frequency of occurrence of genes and genotypes in a population.
This method provides information about the evolution of a species, allows predicting the number of individuals with mutations.
The cytogenetic method is a microscopic study of the number, shape and size of chromosomes in dividing cells of the body.
Examination of the karyotype of an organism using a microscope is used to identify genomic and chromosomal mutations.
Biochemical method – analysis of the composition of substances contained in the body, and biochemical reactions occurring in its cells.
This method can be used to establish the function of a gene, to study metabolic disorders.
Molecular genetic method – decoding the genomes of an organism.
The sequence of nucleotides in the DNA of the organism is established.
Other research methods are also used in genetics.