Genetics, by Dillon

Genetics is a section of biology that covers the science of heredity.  This is the study of genes and the inheritance and variation of traits among living organisms

                An important term in Genetics is Heredity; heredity is the passing of traits from parents to offspring. Our traits come from our genes. Humans have thousands on genes made from DNA that exist in our chromosomes.

                Humans have two sets of twenty three chromosomes there are forty six total. While most cells in our body contain the two sets of twenty three chromosomes our sex cells (sperm and egg) contain one set of twenty three. This is so that every child receives one set of its mother and fathers chromosomes. When a child is conceived it receives random traits from the mother and the father, these results in a completely unique child

                A few types of traits that exist are physical traits such as hair color, eye color and height. There are behavioral traits which are characteristics of the way one acts. This can be observed in dogs like when a golden retriever feels the desire to fetch something. Other traits that can be passed down are medical conditions this can include sickle cell anemia. Cystic fibrosis, heart diseases and certain types of mental illness

                The way traits are determined through what we call alleles, which are expressed through use of capital and lowercase letters. An easy example would the hitchhikers thumb. If you extend your thumb it will either bend back (a hitchhiker’s thumb) or stay straight. We can label the straight thumb with an “h” and the hitchhikers thumb with an “H”. each of us has two alleles for the hitchhikers thumb trait as a result you will have either “HH” “Hh” or “hh” The “H” allele is what we call dominant and when it is paired with a recessive “h” allele the dominant is what shows. As a result HH=hitchhikers thumb, Hh= hitchhikers thumb and hh=a straight thumb. An important thing to know is how we pair the alleles. We use a useful tool called a Punnett square; here is an example for the hitchhikers thumb

	H	h
h	Hh	hh
h	Hh	hh