Which of the following is the best definition of a eukaryote?

a) an organism whose cells each contain a membrane-bound nucleus
b) a one-called organism that does not have a cell wall
c) a one-called organism that does not have a membrane-bound nucleus
d) an organism whose cells each have a cell wall

How do disease caused by bacteria and disease caused by viruses react to antibiotics?

How are mitosis and meiosis similar?

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.