Final answer:
Pleiotropy is a phenomenon in biology where a single gene or mutation causes multiple effects or abnormalities. Examples include Marfan syndrome and sickle cell anemia.
Step-by-step explanation:
In biology, this phenomenon is known as pleiotropy. Pleiotropy is the occurrence of multiple effects or abnormalities caused by a single gene or mutation.
An example of this in humans is Marfan syndrome, where a mutation in the FBN1 gene leads to abnormalities in the skeletal system, cardiovascular system, and eyes. Another example is sickle cell anemia, where a mutation in the HBB gene causes multiple abnormalities including abnormal red blood cells and organ damage.
Pleiotropy can occur because a single gene can affect different biological processes or pathways, leading to a range of abnormalities.