Solve the problem: Collection of issues and challenges in genetics. Isaeva AU Shymkent, 2003., P. 33, № 119-126.
Date: 2015-10-07; view: 515.
Calculate the distance in map units between the genes of seed color and character of the endosperm.
Unstained seeds, smooth endosperm 10
Colored seeds, wrinkled endosperm 14
Unstained seeds, wrinkled endosperm 396
Colored seeds, smooth endosperm 380
Triangulation - a method by which the frequency of recombination and the distance between genes and their sequence is determined.
Crossing, occurring in only one place, is called single crossingover. In 2-points at the same time - double, etc., also it can be plural.
Genes, found in one chromosome and inheriting chained up, compose the group cohesion. Number of linkage groups in each species should correspond to the haploid set of chromosomes.
Genetic map of chromosomes is called the scheme of genes located in this linkage group in the relative positions.
Recombination frequency or crossover frequency can be calculated by the formula:
K = A / B * 100, where A - the number of recombinants
In - the total number of offspring,
K - frequency of crossing, measured in% or map units.
Tasks
1. In maize genes of seed coloring and smooth endosperm dominate over genes of seed coloring and wrinkled endosperm. Homozygous for both dominant features line, was crossed with a line homozygous for the recessive features: during the analyzing F2 crosses with F1 plants the following results were obtained:
Laboratory work №8
Topic: Variability of genetic material on the basis of genes, chromosomes, genomes. Physical, chemical, biological and environmental factors and their effects. The problems of genetic safety. Methods of qualitative and quantitative assessment of mutations. The solution of genetic problems.
Objective: Studying of various factors, mutational variability. The solution of genetic problems.
Properties of an organism are determined by its genotype and environmental conditions in which the development of an organism takes place.
It is necessary to have culture for practical training: a normal fruit fly and its mutations and Curly vestigial. Culture is prepared for 12-15 days prior to class.
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