The main difference between the F1 and F2 generations is that the F1 generation is the first branch generation of the offspring of the parents. But the F2 generation is the second branch generation of the offspring produced by inbreeding from F1 individuals. In addition, the F1 generation is very different from the parent types. In contrast, the F2 generation can exhibit some parental phenotypes. In addition, the F1 generation is important in hybridization in order to preserve the best traits of the parents in the offspring. The F2 generation is now important in inbreeding to maintain stable traits over generations.  

In short, the F1 and F2 generations are two generations of the offspring of a dihybrid cross . Here, a dihybrid or two trait cross is a genetic cross between two individuals who are identically hybrid for two traits.  

Key areas covered  

1. What is the F1 generation - definition, genetics, meaning 2. What is F2 generation - definition, genetics, meaning 3. What are the similarities between F1 and F2 generation - overview of the common characteristics 4. What is the difference between F1 and F2 generation - comparison of the main differences

key terms  

Dihybrid, F1 generation, F2 generation, hybridization, inbreeding, outbringing

What is the F1 generation  

The F1 generation is the first branch generation of the Dihybrid cross. Here, a dihybrid cross is a genetic cross that focuses on the inheritance of two independent traits. Hence it describes Mendel's second law; The independent range .  

genetics  

In general, the parents used in a dihybrid cross are identically hybrid for the two trait tests. Hence, they produce two types of gametes that are the dominant form and the recessive form for both traits. In addition, the F1 generation shows a single genotype that is heterozygous for both traits. Subsequently, his phenotype shows dominant phenotypes of both traits.

Figure 1: F1 generation

Hybridization  

It is important that the F1 generation shows increased heterozygosity, which in turn increases vitality . Hence, hybridization is the genetic process that leads to the F1 generation. In addition, hybridization is one of the two methods of selective breeding. More precisely, in hybridization, breeding takes place between two parents who are genetically different. In addition, the parents can be of different breeds or varieties within the same species. The resulting offspring is also known as a hybrid .   

Auszucht  

Also, the method of breeding that involves unrelated organisms is outbringing. Since outbringing combines the characteristics of different purebred breeds, it increases the variation of a group of organisms through mating. Basically, breeding individuals in two populations of the same genus is an example of outbringing. However, outbringing results in more heterozygous allele combinations within the progeny, with all possible alleles found in the population being randomly mixed. Nevertheless, outgrowth depression is the main disadvantage of outgrowth, which creates the production of unsuitable traits for the current habitat that reduce fitness for the environment.   

What is the F2 generation?  

The F2 generation is the second generation of the Dihybrid cross. Significantly, these are the offspring that are produced by crossing individuals of the F1 generation.  

genetics  

In comparison, the F2 generation is the second branch generation of the dihybrid cross that results from inbreeding individuals of the F1 generation. Therefore, the four types of gametes produced by the F1 generation all contain combinations of dominant and recessive forms of the two test traits. On the other hand, the F2 generation shows a phenotypic ratio of 9: 3: 3: 1 with 9 individuals with both dominant traits, 3 individuals in two sets with one dominant and one recessive trait, or one individual with both recessive traits.

Figure 2: Dihybrid cross

inbreeding  

In addition, inbreeding is the other method of selective breeding as opposed to hybridization or outbringing. Basically, it is about breeding closely related animals, especially over many generations. What is important is that it increases the homozygosity of the offspring. Hence, inbreeding can be used to get pure lines. Hence, the main purpose of inbreeding is to maintain the desired traits of the parents in the offspring. For example, dog breeders, horse breeders, and breeders of exotic animals often use inbreeding to increase a desired genetic trait of the parents in the offspring. However, one of the negative side effects of inbreeding is the emphasis on undesirable traits in the parents, such as physical and mental abnormalities in the offspring.   

Similarities between the F1 and F2 generations  

• The F1 and F2 generations are the two generations of the offspring of a dihybrid cross.  
• The parents of the dihybrid cross are identically hybrid for two traits.  
• A dihybrid cross is also performed to describe the inheritance of two traits.  
• In Mendelian inheritance, a dihybrid cross describes the second law of the law of independent selection.  

Difference between the F1 and F2 generation  

definition  

The F1 generation refers to the first generation of offspring of the offspring of the parents, while the F2 generation is the second generation of offspring of the offspring produced by inbreeding from F1 individuals.  

Method of crossing  

The F1 generation is the result of outbringing, but the F2 generation is the result of inbreeding.  

parents  

The parents of the F1 generation are two individuals who are identical hybrid for two traits, while the parents of the F2 generation are the individuals of the F1 generation.  

Genetic Similarity of Parents  

The F1 generation is the result of a cross between genetically different parents, but the F2 generation is the result of a cross between genetically similar parents.  

Parent genetics  

One parent of the F1 generation is homozygous dominant for both traits, while the second is homozygous recessive. In contrast, the parents of the F2 generation are heterozygous for both traits.  

Gametes  

The two types of gametes that make up the F1 generation are YR and yr, while the four types of gametes that make up the F2 generation are YR, Yr , yR and yr.  

Genotypic relationship  

The F1 generation shows a single genotype; RrYy , which is heterozygous for both traits. Meanwhile, the F2 generation shows RRYY 1: RRYy 2: RRyy 1: RrYY 2: RrYy 4: Rryy 2: rrYY 1: rrYy 2: rryy 1   

Phenotypic relationship  

The F1 generation shows a single phenotype with dominant traits for both traits, while the F2 generation shows a phenotypic ratio of 9: 3: 3: 1.  

The similarity of the phenotypes with the parents  

The F1 generation is quite different from the parental types, but the F2 generation may have some parental phenotypes.  

Effect on vitality  

The F1 generation has increased vitality, while the F2 generation has decreased vitality .  

meaning  

The F1 generation is important in hybridization in order to preserve the best traits of the parents in the offspring. In the meantime, the F2 generation is important in inbreeding to maintain stable traits over generations.  

diploma  

The F1 generation is the first branch generation of the Dihybrid cross. Basically, the parents used in a dihybrid cross are identical hybrids for two traits. The genotype of the F1 generation is also heterozygous for both traits. However, its phenotype shows dominant phenotypes of both traits. Therefore, the F1 generation shows hybridization and their method of breeding is outbringing. In contrast, the F2 generation is the second branch generation of the dihybrid cross produced by crossing individuals of the F1 generation. Usually the phenotypic ratio of the F2 generation is 9: 3: 3: 1 with phenotypes similar to the P generation. The F2 generation is important for maintaining parental characteristics over several generations. Because of this, the main difference between the F1 and F2 generations is the characteristics and importance of the genotypes and phenotypes of each generation.  

References:

1. Hyatt, Donald W. "WHAT'S THE DIFFERENCE BETWEEN F1 AND F2?" JARS v59n4 , Available here.

Image courtesy:

1. “Dihybrid Crosses” by Sonaallii - Own work ( CC BY-SA 4.0 ) via Commons Wikimedia 2. “Figure 12 03 02” from CNX OpenStax ( CC BY 4.0 ) via Commons Wikimedia