Genetics is the study of heredity. Heredity is the passing of traits from a parent generation to the offspring generation. All traits are passed on units called genes. Genes are units of heredity found in DNA, and it contains genetic material.
Every gene is composed of two alleles. Alleles are the sub-unit of heredity. One allele comes from the mother’s DNA, and the other one comes from the father’s DNA. Two alleles make one gene.
To be dominant or recessive is inherent to a gene or allele. If a gene or allele is recessive, a dominant gene or allele will take over. If the recessive allele is present, you will not be able to see it physically. Capital letters constitute dominant alleles and lowercase letters constitute recessive alleles.
Many of are traits are actually controlled by multiple versions of the same gene. Gene segments activate to make a cell specialize. This is possible because of our personal epigenome. An epigenome is an “outer layer” of genetic information found in a person’s DNA. It serves as a punctuation marker, making it easier to “read” gene expression and activate or silence certain genes.
Incomplete dominance occurs when there is a blending of traits due to the presence of multiple dominant genes. This is because multiple dominant genes are present and all of them show equally. Codominance is another intermediate pattern of inheritance. Codominance is when both alleles contribute equally to the phenotype, resulting in a sharply contrasting appearance in color/ variation, etc… through the organism.
Vocabulary terms (not included above):
Carrier- An organism that does not exhibit a genetic disorder ir disease but contains an allele which could potentially be passed along to their offspring.
Sex-linked trait- A trait that is passed specifically on the X or Y chromosome.
Karyotype- The chromosomal profile of a person.
Pedigree- A chart that assists with tracking select traits through different generations.
Credits:
Created with images by orphanjones - "her favorite jeans" • Ryan Somma - "Gregor Johann Mendel" • Todd Ryburn - "Sasha out in the backyard" • AdinaVoicu - "brown eyes iris gene" • Caroline Davis2010 - "DNA" • White77 - "family holiday people"