Is a group of similar oraganisum that can mate with each ohter and prouduce fertile offspring

Look at the figure above. which atmospheric layer has around 80 percent of the mass of the earth's atmosphere? (hint: it's where the clouds seen on earth are formed.) a. exosphere b. troposphere c. stratosphere d. thermosphere

The transport tubes for food coming down the plants are called?

Adistinctive characteristic of mammals that is not observed in other vertebrates is