AP+Sex+Determination+Presentation

In my presentation I will be informing the class about the X and Y chromosomes. Males are made up of the combination of XY and females are determined by the XX chromosomes. There are 46 chromosomes in the body all together. Males determine the off spring because they can create both the X sperm and the Y sperm. The X and Y chromosomes determine sex because only one chromosome is different.

The Y chromosome is only in males. If the Y sperm fertilizes an egg then the embryo becomes a male. The Y chromosome represents two percent of the total DNA. It only contains 70-400 genes not near as many genes as the X chromosomes.

The X chromosome is in both male and female. A child becomes a female when the X sperm fertilizes an egg in the embryo. In the absences of the Y chromosome the human fetus will develop into a female. The X chromosome also contains more genes than the Y chromosome because there are X chromosomes in both male and females.

Ideograms is a chart made up of the X and Y chromosomes. It shows the difference between the X and Y. Ideograms are used to describe the location of genes on the chromosome and it a banding pattern. The X chromosome is longer than the Y chromosome because it has more genes. Since the X is longer there no opposing genes to cancel out the Y genes, therefore the X is more dominate.

To determine the location of a gene you look at the first letter or number. The first number or letter represents the chromosome. Chromosomes 1 through 22 (the autosomes) are determined by their chromosome number. Each chromosome is divided into two sections, arms, based on the location of the narrowing, centromere. The shorter arm is called p and the longer arm is called q. The chromosome arm is the second part of the gene’s address. "For example, 5q is the long arm of chromosome 5, and Xp is the short arm of the X chromosome."

The pedigree chart shows the outcome of having a male or female. It shows the direct blood lines in your family history. The circle means female and the square means males. The horizontal line means marriage and the vertical line means the parent of the child. When the circle or square is shaded it means they have a dominate trait and when the circle or square is not shaded it means the person does not have a dominate trait.

Reference: http://ghr.nlm.nih.gov/chromosome=Y http://www.biology-online.org/2/6_sex_chromosomes.htm http://ghs.gresham.k12.or.us/science/ps/sci/soph/genetics/notes/sex.htm http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation