Incompletely Dominant Allele When two different alleles are both dominant over another allele, but not dominant over each other. An example is a cross between red flowers and white flowers that produce offspring that are pink.

Co-dominant Allele A single gene that has more than one dominant allele. An example is a cross between red flowers and white flowers that produces red and white (mixed) flowers

Multiple Allele Trait More than two alleles that code for a particular trait or characteristic. The human blood type is a good example of a multiple allele trait.

Sex-linked Allele An allele carried by a sex-linked chromosome. Color blindness and the disease hemophilia are sex-linked traits in humans.

Monogenic TraitA trait that is determined by one gene. Examples include an inherited disease, such as Huntington’s disease or polycystic kidney disease.

Polygenic Trait A trait that is determined by two or more genes Examples include height, eye color, hair color, skin color.

Antigen A harmful substance which enters the body which causes the body to make antibodies as a response to fight off disease. An example of an antigen is a common cold virus which causes the body to make antibodies which help prevent the person from getting sick.

Antibody A protein molecule that can be found in the blood and is meant to attack bacteria, viruses. Antibodies are used by humans to fight antigens and keep the body healthy

Pedigree The definition of a pedigree is a record of known relatives or ancestors Examples of pedigrees include a family tree or a list of relatives for a purebred animal.

Carrier An organism that carries a gene for a trait but does not show the trait itself.. Carriers can produce offspring that express the trait by mating with another carrier of the same gene.

Diagnosis The process of finding out what is causing symptoms, a disease or injury in a patient Doctors use tests and other data collected from the patient to diagnose the problem.

Symptoms A feeling or abnormal condition which is noticed by a patient, and may indicate the presence of disease. Some examples of symptoms include: Headaches, a rash, a fever, a growth or tumor, trouble breathing, being tired, etc.

Prognosis The predicted outcome of a disease and the chances of recovery. A prognosis helps to decide if the patient will get better or be killed by a disease.

Treatment The manner in which a disease is cared for or dealt with. Treatment might involve drugs, chemotherapy, radiation, physical therapy or other methods.