How to solve genetics problems - step by step

F1 Generation Definition The F1 generation refers to the first filial generation. Filial generations are the nomenclature given to subsequent sets of offspring from controlled or observed reproduction. The initial generation is given the letter “P” for parental generation. The first set of offspring from these parents is then known as the F1 generation. The F1 generation can reproduce to create the F2 generation, and so forth. Scientists use this designation to track groups of offspring as they observe the genetics of various generations. Examples of F1 Generation A Monohybrid Cross When the “Father of Genetics”, Gregor Mendel, was first unfolding the secrets of pea genetics, he started by producing lines of pure-breeding peas. Peas are a variety of plant which can self-fertilize, meaning the male part of the plant can fertilize the eggs produced by the female part of the plant. When allowed to self-fertilize, these plants would produce offspring with the same traits. For example, the pea pods on one plant and all its offspring would produce green pods, while another plant would produce all yellow pods. To unlock the secrets of how these traits were passed to offspring, Mendel decided to cross these two lines of plants. Mendel took the pollen from yellow-pod plants and transferred it to green-pod plants. He then did the opposite cross, of green-pod pollen to yellow-pod flowers. Scientist now designate these original two plants as the parental generation or simply the P generation. Once fertilized, the parental generation grows peas, which contain the genetic information for the first generation of offspring, or the F1 generation. Mendel planted these peas and noticed a curious fact about the color of the pea pods they produced: they were all green! The yellow-pod plants had contributed genetically to the F1 generation, but only green-pods were found. Mendel had to do one further experiment to determine what was happening with the genetics controlling pod color. Mendel took a plant from the F1 generation, and allowed that plant to self-fertilize. He then planted and observed the offspring from this cross. Because it is a cross of the offspring, it represents the second filial generation, or F2 generation. Mendel observed that the F2 generation contained a mixture of green and yellow pods. Mendel showed that the 3:1 ratio of yellow-pod to green-pod plants could only be obtainable if both parents carried a copy of both the yellow and green alleles, and that the yellow allele had to be dominant over green. Modern scientists now describe the cross of Mendel’s F1 generation as a monohybrid cross. The individuals in the cross all had one allele for green pods and one allele for yellow pods, making them hybrids. This cross only examined one trait, however many more traits can be observed at once. #genetics #F1Generation #geneticCross #hybrid #plants