The study of mechanisms of inheritance in animals and plants by using cells in culture. In such cells, chromosomes and genes can be reshuffled by parasexual means rather than having to depend upon the genetic recombination and chromosome segregation that occur during the meiotic cell divisions preceding gamete formation and sexual reproduction. Genetics is concerned with the role of genes and chromosomes and their environmental interactions in the development and function of individuals and the evolution of species. Genetic analysis of complex multicellular organisms classically requires multigeneration families. Because fairly large numbers of progeny of defined matings have to be scored, genetic analysis of animals and plants with long generation times, small families, or lack of controlled matings is difficult and slow.