How do prokaryotes differ from eukaryotes?
prokaryotes are always multicellular, while eukaryotes are always single celled.
prokaryotes are always single celled, while eukaryotes can be single-celled or multicellular.
there is no difference between the two types of cells.
prokaryotes have a nucleus, while eukaryotes do not.

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Which of the following is the best definition for the process of photosynthesis? a.) plants digest sugars to make energy. b.) plants use oxygen and glucose to make carbon dioxide. c.) plants use sunlight and carbon dioxide to make sugars. d.) plants use sunlight to make chlorophyll and chloroplasts.

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.