in the late 1600s, english astronomer edmond halley presented a model of earth’s structure. helmet originally claimed that earth was

What would happen to the nutrients in an ecosystem if decomposers, such as bacteria, didn’t exist there?

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above