The value of screening mammograms was questioned in November 2009 when the U.S. Preventive Services Task Force recommended that routine screening mammograms for women with an average risk of breast cancer should start at age 50 instead of age 40.or example, mammograms have been shown to lower the risk of dying from breast cancer by 35% in women over the age of 50. In women between ages 40 and 50, the risk reduction appears to be somewhat less.
Vocabulary alkane alkyl group hydrocarbon An alkyl group is a piece of a molecule with the general formula CnH2n+1, where n is some integer. For example, a methyl group (CH3) is a fragment of a methane molecule (CH4); n = 1 in this case. The-yl ending means a fragment of an alkane formed by removing a hydrogen.n alkyl group is a piece of a molecule with the general formula C n H 2n+1, where n is some integer.
-al, a suffix designating a compound containing a member of the aldehyde group: chloral, ethanal.