Which organelle can be compared to a security guard who decides whom may enter a building and whom may not?
O cell membrane
O cytoplasm
O endoplasmic reticulum
O mitochondrion

Which group of algae is characterized by unicellular organisms and includes some members that would be better classified as zooflagellates? euglenophytes red algae sporozoans green algae

Which statement about relative potential energy of electrons is correct? a. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 2 s orbital of the second electron shell. b. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 3 p orbital of the third electron shell. c. an electron in the 3 p orbital of the third electron shell has more potential energy than an electron in the 2 p orbital of the second electron shell.

Prokaryotic and eukaryotic cells are different in many ways other than the presence or absence of a nucleus. if both archaebacteria and eubacteria are prokaryotic cells, then why are archaebacteria more closely related to eukaryotic cells than they are to eubacteria?