Genetic Disorders: Annotated Bibliography

4. Clear wing, Black eye, and Hairless (c, b, and h) are linked, recessive traits carried on

The parents are both homozygous. The homozygous dominant would represent the wild type. And the homozygous recessive would represent the other fly parent of a different strain. The F1 generation would consist of 100% Wild Type but they would all be heterozygous in carrying the recessive gene.

Apply your understanding of how alleles assort and combine during reproduction to evaluate a scenario involving a monohybrid cross.

_____ In swine, when a pure-breeding red is crossed with a pure-breeding white the F1 are all red. However, the F2 shows 9 red, 1 white and 6 of a new color, sandy. The Sandy phenotype is most likely determined by

with a frequency of 25%, and crossover gametes between genes Y and Z are observed with a

It would be expected that the mutant F1 flies would be heterozygous for the allele responsible for the grounded trait. If two F1 flies were mated, the percentage of flies that would be expected to be wildtype in the F2 generation would be 25% mutants given that the mutant allele (ap) is predicted to be recessive and, leaving 75% to be wildtype (ap+).

This lab had 2 exercises. Exercise 9.1 involved observing pictures of 60 F2 offspring and recording the phenotypes for 6 different traits. Exercise 9.2 required us to perform the “chi-square test” to determine whether the data we collected matches the standard Mendelian ratio.

11. The progeny of a Drosophila female (heterozygous at three loci: y, ct, and w) crossed to a wild type male are listed below:

Muscular dystrophy (MD) is a genetic disorder caused by incorrect or missing genetic information that leads to the gradual weakening of the muscle cells. Various causes lead to weak and deteriorating muscles depending on the type of muscular dystrophy the patient was affected by. However, there are many causes for muscular dystrophy due to the fact that there are thirty forms of muscular dystrophy, which are categorized under several categories. All are ultimately caused by autosomal recessive, autosomal dominant, sex-linked, and random mutations in very rare cases.

Based upon observation of the F1 generation, we hypothesize that the inheritance of the white-eye (W) mutation is sex-linked and recessive wild type.

This experiment looks at the relationship between genes, generations of a population and if genes are carried from one generation to another. By studying Drosophila melanogaster, starting with a parent group we crossed a variety of flies and observe the characteristics of the F1 generation. We then concluded that sex-linked genes and autosomal genes could indeed be traced through from the parent generation to the F1 generation.

This experiment studied Mendel’s law of independent assortment through observing three generations of Drosophila melanogaster. His law was examined by looking at the inheritance patterns that predicted genetic linkage, mapping distances and interference. Genes are located along chromosomes and the distances between them vary. During recombination, these genes may become unlinked. The frequency to which this occurs relies on the recombination frequency, in which a greater value represents a greater distance between two loci. By looking at inheritance patterns and recombination frequencies, this experiment showed that white eyes, short wings and forked bristles are X-linked traits. As well, dumpy wings and brown eyes are autosomal traits. The expected ratio of a dihybrid cross of 9:3:3:1, was used to determine linkage between two loci. This was then verified using a chi-square test. Through analysis of our results, linkage existed between white eyes and short wings, as well as between short wings and forked bristles. Linkage was also found for the strains that had dumpy wings and brown eyes.

Hypothesis: The hypothesis is that Normal wings (NN) are the dominant trait and Butterfly wings (bb) are the recessive trait. The original parents are purebred (homozygous dominant (NN) and homozygous recessive (bb). The F1 generation is predicted to displays 100% Normal wings population of heterozygous (Nb). The F-2 generation is predicted to display a 3:1 Mendelian ratio of Normal wings to Butterfly wings.

For each pair of traits crossed, one alternative was not expressed in the F1 hybrids, although it reappeared in some F2 individuals

The father of modern genetics, Gregor Mendel is accredited for discovering the basic principles of genetics, he is most known for his experiment with peas which later lead to the study of heredity Mendel most important conclusions where what we know today as principles of Mendelian inheritance which consisted of two principles the law of random segregation and the law of independent assortment (Gregor Mendel Biography.com, 2017). In this experiment, we utilized Drosophila melanogaster to study mutant phenotypes, observed basic patterns of Mendelian inheritance, and develop a hypothesis based on the cross results. The objectives of this experiment are to analyze drosophila mutants by observing the phenotypes, also to observe the expected patterns of Mendelian inheritance, develop a hypothesis on the mode of inheritance and phenotypic ratios, and finally analyze the results using a Chi-Square Analysis (Department of biology 2017). We predicted in our hypothesis that in the monohybrid cross of Drosophila melanogaster, the phenotypic ratio would be of 3:1 for the F2 generation