In a certain ecosystem, caterpillars eat grass. Field mice eat the caterpillars and seeds from the grass. Snakes eat the mice. Hawks eat both the snakes and mice. Such an arrangement would be considered a(n):

A. food web.
B. food chain.
C. ecosystem.
D. second trophic level.

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

The cluster of developing cells from conception until birth is called an

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?