Recessive means a weaker trait in genetics. Genes that mask other genes are called dominant and genes that can be masked are the weaker or recessive genes. Cystic fibrosis is a hereditary disease that mainly affects Caucasian children of European decent. The disease is caused by a defect in which cells make chloride pumps but fail to install them in the plasma membrane. Both parents must carry the recessive gene for a child to inherit the condition.
