<%@ page language="java" contentType="text/html" %> <%@ include file="/securityNoLog.jsp" %> <%@ taglib uri="/WEB-INF/tlds/vgTaglib.xml" prefix="vg" %> To determine whether F2 individuals that display the dominant phenotype are all the same we do a test-cross. Select an F2 individual with a dominant phenotype and cross-it to the parent that displays the recessive trait. You will need to test a number of individuals to determine whether all F2s produce the same types of offspring.