Lab report
Introduction.
The Mendelian genetic effort, revolve around the inheritance of biological characteristics that trail the proposed Mendelian laws brought forward by Gregor Mendel (He & University of Chicago, 46). These regulations advocate for independent assortment, trait dominance in alleles, and the segregative capability of alleles. Thus the hypothetical endeavor of this report is to ascertain the identity of the first filial generation -F1, based on the phenotypic quotients of the second filial-F2 cohorts
Fruit fly drosophila is considered ideal in genetic experiments, because they share the majority of their genes that cause diseases with humans up to 75 percent. Additionally Fruit flies are accepted to work within the research scenario because; they are comparatively easy to take care of, due to their low requirement of food and space. This enables the researchers to keep up to millions of the flies in biological laboratories. The aabb, represents recessive genes, while AABB, represents dominance (Lovering& Video Education Australasia, 23). Thus the transfer of characteristics from one generation to the other. The vulnerability to gene mutations occurs due to the elimination, translocation and omission of alleles during combination and inheritance.
An organism halves its genetic composition upon undergoing meiosis. This in preparation for gene combination with another organism. This explains that meiosis is a process of forming gametes. It is notable that, each gamete consists of a copy of each gene. All gametes are haploid and must account for each trait. The second filial generation (F2) is obtained by inbreeding of the F1 generation gametes. A 9:3:3:1 ratio is expected in a dihybrid cross, since there is no epistasis (Lovering& Video Education Australasia, 23).
The punnet square is useful in genetics because of its uncomplicated nature of comprehension relative to genetic cross, the resultant offspring genotypes, and their corresponding filial phenotypes.
The following off-spring is produced when these genotypes and phenotypes are sorted
Phenotype: Antennae, big eyes 9 Genotype: AABB 1
AABb 2
AaBB 2
AaBb 4
Phenotype: Antennae, small eyes 3 Genotype: AAbb 1
Aabb 2
Phenotype: No antennae, big eyes 3 Genotype: aaBB 1
Phenotype: No antennae, small eyes 1 Genotype: aabb 1
The 9:3:3:1 represents a combination of both the Principles of Segregation and the Independent Assortment. Segregatively because each allele of each gene occurs in gametes with equal chance, while the independent assortment is indicated by by the independent occurrence of the alleles of the antenna characteristic in a gamete.This ration is consistent with the following
- No lethal genes
- No epistasis
- Complete dominance and the Independent assortment of two loci
References
He, B., & University of Chicago. (2012). Using a Drosophila natural variation to study the role of positive selection in cis-regulatory evolution and the genetic basis of a complex disease trait.
Lovering, M., & Video Education Australasia. (2002). Genes & inheritance: Priests, peas, pedigrees and punnets. Bendigo, Vic: Video Education Australasia.
