How do prokaryotes lend stability to an ecosystem?

Apart of the periodic table is shown. a portion of the sixteenth and seventeenth columns of the periodic table is shown. column 16 reads eight oxygen, 16 sulfur, and 34 selenium. column 17 reads nine flourine, 17 chlorine, and 35 bromine. which of the following elements is less reactive than the others? bromine (br) oxygen (o) selenium (se) sulfur (s)

What vitamin gives carrots and sweet potatoes their orange color?

Steven hawking is on record as saying that viruses can be considered a form of life. considering the list above, what might be his evidence? a) item 5 b) items 1 - 3 c) items 4 - 7 d) items 1 & 2