Tour of the Basics

http://learn.genetics.utah.edu/content/begin/tour/

What Is DNA?
DNA (deoxyribose nucleic acid) is double helix structured composed of two strands of A, T, G, and Cs that combine with each other in the complimentary strand, by specific pairs - A with T and G with C - and each collectively, are used in a gene.

What is a Gene?
Genes are made up of DNA and are specific in building proteins. If there is an error or mutation within the gene, it will cause a disorder and may be disadvantageous. Since genes contain instructions for building proteins, there are in fact many sorts of a proteins, which result in functions for all sorts of things.

What is a Chromosome?
A chromosome is a packaged fit of DNA into a cell. Depending on the organism, each cell holds a different number of chromosomes, for humans, a cell holds 46 chromosomes. By looking at chromosomes, you can observe something such as the sex of a human for example; you can see the difference between female chromosome (XX) and male chromosome (XY).

What is a Protein?
Each protein has a specific role such as receptor proteins, sending signals across the nerve cells into the brain, or structural to make the cell stay in it's shape. There are many types of proteins other than these two that play specific roles in the body. To make proteins, it uses genes as it's "blueprint" by making mRNA then travels with later is moved into the ribosomes to produce more.

What is Heredity?
Heredity is the set of traits that defined by our genes. It is both contributed by environmental factors (chemical exposure) and the chromosomes inherited from our parents, both father and mother. Because of random assortment, each child will never have the exact combination of chromosomes.

What is a Trait?
A trait is a unique feature that separates one person from another noticeably. There are three types, physical behavioral, or predisposition on medical condition. Each can be genetically or environmentally influenced. The genes or alleles passed on by both parents (one from each) determine what trait someone will have.