What is the greatest difference in hydrogen and hydroxide ions?

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism

The similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between organisms in both locations?

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils