Some regions of chromosomes are more likely to cross over compared to others. such a region is called a "hot spot". gene a and gene b, which are in a hot spot for crossing over, are 5,000,000 bp apart on the same chromosome. gene c and gene d are also 5,000,000 bp apart but they are not in a hot spot. if you conducted two-factor crosses to compute the map distance between genes a and b and between genes c and d, would the map distances be the same between a and b compared to cand d? explain why or why not.
If neither of the pairs of genes was in a hot spot, the map distance would likely be the same. However, in this case it is said that although both pairs of genes are 5,000,000 bp apart, genes A and B are present in a hot spot. This means genes A and B are more likely to experience recombination and produce recombinant offspring in the F2 generation due to crossing over. As a result, the map distances for A and B will be larger than the map distances for C and D because a map unit is the number of recombinant individuals divided by the total number of individuals, which is then multiplied by 100. Since a greater percentage of individuals would be recombinant in the F2 generation, A and B will have a larger map distance.
lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.
genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).