BIOLOGY GENETICS PROBLEMS AND ANTIBIOTICS - Essay Example

All combinations are represented and would therefore occur. After pollination a plant with rough stems and yellow flowers with pollen from another plant of the same species having rough stems and white flowers, adequate precautions being taken to prevent pollination occurring in any other way, 80 seeds were obtained. The F1 phenotypic ratio is 3:1:3:1, rough yellow, smooth yellow, rough white, smooth white. The genotypic ratio is 1:1:2:2:1:1. All combinations have occurred, but two showed elevated results according to genotypic and phenotypic ratios.

In the fruit fly Drosophila the wild type (normal) is grey in colour with wings that extend beyond the tip of abdomen. Among the mutants of Drosophila are two which are respectively distinguished by dark body colour (ebony) and a vestigial condition of the wings (vestigial) In guinea pigs, black coat colour is dominant to brown and short hair is dominant to long hair. These characters are not linked. A breeder has only stocks of pure breeding, long-haired brown and pure breeding, short-haired black guinea pigs.

Since the breeder only has stocks of pure breeding long haired brown which would be homozygous recessive (bbss) and pure breeding short haired black which would be homozygous dominant (BBSS), F1 would yield 100% black short haired guinea pigs, with heterozygous genotype BbSs. (a) Self-pollination of one of the F, plants – self pollination of genotype TtGgRr would yield 64 genotypes total, 27 possible genotype combinations, and 8 phenotype combinations. The most notably going to the heterozygous genotype TtGgRr with 8 times.

Phenotypes were tall green round, short green round, tall green wrinkled, short green wrinkled. There were no yellow plants. There were 8 possible genotypes yielding only genotypes leading to green and no yellow plants. Normal (wild-type) strains of the fruit fly Drosophila melanogaster have greyish brown bodies if developed on food media free of silver salts, but