When jenner developed the first vaccine he was using the observation of milk maids who
a. after having cowpox they were immune to smallpoxb. after having chickenpox they were immune to smallpoxc. after being infected with the flu virus they were immune to smallpoxd. after developing hiv they were immune to smallpox

What is the difference between a meteoroid and a meteor?

What two factors does carrying capacity compare? population size and resource use population growth and resource availability resource use and time population size and time

The images show two species of tree frogs in a particular region. the gray tree frogs are adapted to the trees of the woodlands, while the green tree frogs can survive in woodlands or grasslands. the gray frog was abundant in the woodlands. because of climatic changes, most of the trees in the region died, and the woodlands changed to grasslands. in such a case, the . the gray tree frog is closely related to the green tree frog genetically, but they have different mating calls. this suggests that speciation occurred because of .