This is a poisonous substance that is produced by living cells or organisms and is capable of causing disease when introduced into living tissues.

Environmental differences within ecosystems are generally caused by

Which event would lead to primary succession of a forest?

Which of the following describes how binary fission and mitosis are similar? a)they are both used for growth or repair b)they both break down membrane-bound nuclei c)both invoke the replication of a single stand of dna d)both replicate genetic material