During the ordovician period of the early paleozoic era, the first jawless fishes appeared on earth. these organisms belong to a group known as

a vertebrates
b mollusks
c trilobites
d corals

Which statement describes john tuzo wilson’s contribution to the theory of plate tectonics?

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?

The green colored pigment in chloroplasts is? a. nitrogen b. chlorophyll c. chlorophorm d. chlorofloromethane