The main provisions of the chromosome theory of heredity:
– Genes in the chromosomes are linearly arranged in a certain sequence. Allelic genes are located at the same loci of homologous chromosomes.
– Genes located on the same chromosome form a linkage group and are inherited together. The number of linkage groups is equal to the number of pairs of chromosomes.
– Gene linkage may be impaired as a result of crossing-over, which occurs during conjugation of homologous chromosomes in prophase I of meiosis.
– The crossover frequency is proportional to the distance between the genes: the greater the distance, the higher the crossover frequency and vice versa.
– For a unit of distance between linked genes, 1 morbid is taken – the distance at which crossing-over occurs with a probability of 1%.
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.