Prader-Willi syndrome is a disease that is present from birth (congenital). It affects many parts of the body. People with this condition feel hungry all the time and become obese. They also have poor muscle tone, reduced mental ability, and underdeveloped sex organs. Causes Prader-Willi syndrome is caused by a missing gene on chromosome 15. Normally, parents each pass down a copy of this chromosome. The defect can occur in a couple of ways: The father's genes are missing on chromosome 15 There are defects or problems with the fatherâs genes on chromosome 15 There are two copies of the mother's chromosome 15 and none from the father; These genetic changes occur randomly. Persons who have this syndrome usually do not have a family history of the condition. Symptoms Signs of Prader-Willi syndrome may be seen at birth.
Definition of momentum for English Language Learners. : the strength or force that something has when it is moving. : the strength or force that allows something to continue or to grow stronger or faster as time passes.
Exploring Momentum Momentum is an object's mass multiplied by its velocity. This is expressed in a formula that reads p = mv. It has both direction and magnitude, making it a vector quantity. Law of Conservation of Momentum Examples One example would be a vehicle accident.