In ecosystems the flow of is one way, while is/are recycled within.

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this

Biology ! the conversion of inorganic carbon to organic carbon by plants during photosynthesis is known as _[blank]_. filtration immigration reabsorption primary production