Scientists argue that the first organisms on earth were ___ - - - that is, their metabolism did not require oxygen.

1) multi-cellular

2) anearobic

3) aerobic

Why is bacteria a necessary part of the nitrogen cycle

How is continental crust different from oceanic crust? Oceanic crust is thinner and more likely to sink. Continental crust is more dense and lighter. Continental crust is thicker and more likely to sink. Oceanic crust is thicker and more dense.

Which of these is most likely to happen if parallax measurements of star distances are taken after a gap of six months? The results would be accurate the results would be inconsistent the results would not be valid the results would not be repeated

Is animal dung a fuel

Which organelle aids in the production and movement of proteins and other materials through the cell?

Competition over resources occurs between organisms

What is the percentage of human guanine

A gram-negative, nonsporulating rod that is highly motile, oxidase negative, facultatively aerobic, ferments glucose, and urease-positive is likely to be of which genus?

3. Explain Peter and Rosemary Grants study of finches. How did this support Darwin's hypothesis.

Can an organ belong to more than one system? Why?