Genes are the basics of genetics (Nadeau & Dudley 2011, 1015).
Genes are packed in bundles referred to as chromosomes. They are threadlike structures that are located inside the nucleus of a living being. For a human being, there are 23 pairs of chromosomes meaning that there are a total of 46 chromosomes (De Koning & Haley 2005, 386). Of these pairs of chromosomes, 1 pair is the sex chromosomes that determines the sex of an individual and their body characteristics. The other pair of chromosomes is referred to as autosomal chromosomes and their function is to determine the rest of the body make up.
Gregor Mendel is referred to as the father of genetics due to his study of the inheritance in pea plants. A gene contains an allel that is inherited from both parents i.e. tongue roller and non-tongue roller are alleles for the ability to roll the tongue and more than two allels can exist for any specific gene but only two of them will be found in an individual. Allels may be similar or different and if they are identical for a gene are referred to as a homozygous. If the organism has two different alleles for a gene, it is a heterozygous. He hypothesized that these allels separate randomly during gametes production i.e. an egg and a sperm that will carry only one allel for the inherited trait. When they unit each gamete will contribute its allele restoring the paired condition of the offspring (Moore 2001, 21). This is referred to as the law of segregation. He also found out that each individual pair of alleles will separate independently of the other pair of alleles during the process of gamete formation and referred this as the law of independent assortment. He also described that if the two allels of an inherited pair are different (heterozygous), only one will determine the organism’s appearance and will be referred to as the dominant allele while the other one is the recessive allele. He referred this as the ...Show more