Microscopes helped scientists to observe all of the following characteristics EXCEPT: A.
which organisms have a nucleus

B.
which organisms have a cell wall

C.
which organisms sexually reproduce

D.
which organisms are multicellular or unicellular

PLEASE HELP IM NOT THAT GOOD IN SCIENCE!!!

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

Multicellular organisms use cell division, mitosis, for growth and the maintenance and repair of cells and tissues. single-celled organisms may use cell division as their method of reproduction. regardless of the reason for mitosis, the process ensures genetic continuity. what is the step in the cell cycle that ensure genetic continuity?

Which heredity condition causes a buildup of mucus in lungs and pancreas? a. cystic fibrosis b. heart disease c. huntington's disease d. sickle cell anemia