Why is the haemoglobin concentration in lungs higher than that in other tissues.

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

Ecology can best be described as the study of what

How are viruses different from eukaryotic cells?