Blind copy is the term used to describe a situation in which the same message, email, or letter is sent to several different people, without these people knowing about each other, or knowing about those copies. In short, this term refers to when the writer of a letter sends a copy to a third party without the knowledge of the person receiving the original letter. It can also be called Blind carbon copy or Blind Courtesy Copy.
The sickle cell anemia trait is found on a recessive allele of the hemoglobin gene. This means that you must have two copies of the recessive allele — one from your mother and one from your father — to have the condition. People who have one dominant and one recessive copy of the allele won't have sickle cell anemia.
