Why is dna replication called " semi - conservative "?

Organisms are classified, or grouped into categories, based on similarities in their characteristics and/or evolutionary relationships. the study of how organisms are classified is known as

Afamily has a y-linked disease that affects the father. what is the chance of a male offspring inheriting the same disease? oa. 100% ob. 50% oc. 25% d. 0%

Why reason best illustrates why hershey and chase chose to use viruses in their experiment?