Christine Robson
April 14th, 2016
Lab Section 2010: Thursday; 9:30am
Professor Gibbons
James Madison University
Introduction:
Sex determination in organisms can be controlled by either the inheritance of sex chromosomes or environmental conditions. In many organisms, the sex of a developing embryo is determined by the inheritance of sex chromosomes that contain genetic information which determine the sexual phenotype in the developing embryo (Hurney et al. 2016). The sex determination of humans is determined by chromosomal inheritance. Humans have two sex chromosomes, X and Y; a human embryo will develop into a male if the embryo inherits an X and Y chromosome and develop into a female if the embryo inherits two X chromosomes. Sex determination can also be influenced by a variety of environmental factors such as temperature, parasites, and population density. The sex determination of a turtle is dependent on the incubation temperature of the eggs. Cooler temperatures result in female sexual development whereas warmer temperatures result in male sexual development (Hurney et al. 2016).
Ceratopteris richardii, also commonly known as C-Fern, was used in this experiment to determine the influence of population density …show more content…
richardii since the presence of male gametophytes creates more genetic diversity. To test this hypothesis, six petri dishes labeled A-F were prepared with varying densities of gametophytes. Each petri dish contained a specific quantity of spores that was mixed with distilled water in a test tube. Each test tube was evenly spread on the agarose enriched with nutrients required for the spores to germinate. The plates were then incubated for three weeks under gro-lamps to allow the cells to divide mitotically to produce the gametophyte generation (Hurney et al.