Why is there chloroplasts in leaf cells but not root cells?

This aquarium exhibits biotic and abiotic factors in an aquatic environment. one of the abiotic factors is

Which is an example of a population?

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