1.) Fertilization is the process in which both a woman’s and a man’s twenty-three chromosomes pair up to make a new cell. A zygote is a new cell that is formed from gametes after fertilization and make up the individual’s genotype.2.) Infertility is described as the inability to get pregnant after around a year. Causes of infertility can be low sperm production, poor sperm quality, or low sperm movement. Treatments for infertility can include artificial insemination, fertility drugs, and in vitro fertilization. 3.) Genes are tiny portions of DNA that contain instructions for an organism to grow. Chromosomes are the structures that house genes that pair up with each other. 4.) The chromosome that comes from the sperm cell will be the determinant. This is because it will either be an x or a y that pairs with the egg cell’s x.5.) In dominant-recessive inheritance, the dominant gene is the main influence for the phenotype. However, the recessive gene is not expressed and just remains as a part of the genotype.6.) The genotype is made up of all an individual’s actual genes. However, the phenotype consists of all the characteristics that can actually be seen on another organism.7.) Chromosomal disorders are the result of an abnormal number of chromosomes in an individual’s cells. Down syndrome is a common chromosomal disorder that results from an extra chromosome on the 21st pair. Another chromosomal disorder is Fragile X syndrome, caused by mutations on the child’s x chromosome and causes cognitive disabilities; it is also highly associated with autism. PKU is another disorder that is the result of phenylalanine building up and potentially causing mental disability in affected children. 8.) Nature vs. Nurture is an ongoing discussion of whether a child’s genetic composition or a child’s family background and how they were raised is the main cause of the child’s behavior. Heritability describes just how much genes are the cause of all the differences between people in a population. This is figured up by geneticists, who give each characteristic measured a rang of 0 to 1.00. Epigenesis is the idea that development is the cause of genotype and the child’s environment working together to influence them. An example of nonshared environmental effects would be the theory of genotype – environment effects because it states that our genes alone are the actual cause for our environment. Since everyone has different genes, this would result in features of our environment that can not be shared with others.