4 What is a difference between prokaryotic and eukaryotic cells? A. Prokaryotic cells always have cell walls, but eukaryotic cells do not. B. Eukaryotic cells do not have membrane-bound organelles, but prokaryotic cells do. C. Prokaryotic cells do not have a nucleus, but eukaryotic cells do. D. Organisms with eukaryotic cells are always multicellular, but organisms with prokaryotic cells are not.

What feature of cell theory is best demonstrated in the image

If water were a non polar molecule, how would its properties be different ? a.) water would be a much lighter molecule b.) water would be able to climb up inside plants c.)water would not be able to form hydrogen bonds d.) water would stick together much more strongly

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?