The inner core of the Earth is a metal spinning ball made of nickel and iron. It spins faster than the earth rotates and is hotter than the surface of A. Mars
B. The Sun
C. Lava

Which of the following is the best definition of a eukaryota? a. a one-celled organism that does not have a membrane-bound nucleus b. a one-celled organism that does not have a cell wall c. an organism whose cells each contain a membrane-bound nucleus d. an organism whose cells each have a cell wall