You have three groups of guinea pigs, ones from inbred strain A, ones from inbred strain B and guinea pigs that are the F1 progeny of matings between A and B guinea pigs. All guinea pigs are infected with a newly-evolved version of LCM virus. TC cells from an F1 hybrid guinea pig could attack infected cells from .

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.