Select the correct answer from each drop-down menu. (drop-down menu)tends to raise CO2 levels in the atmosphere, but
(drop-down menu) tends to lower CO2 levels in the atmosphere.

25) a student takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are: liquid a: the solid dissolves quickly. liquid b: the solid appears unchanged. liquid c: a brownish colored liquid is produced. liquid d: fizzing occurs and the well becomes warmer. in which well does a physical change occur?

Photosynthesis uses co2 and cellular respiration produces co2. we call the point when the two processes are in balance--when there is no net production of co2--the compensation point. how might you limit one of the processes in order to achieve a compensation point?

What is a general feature of a species that varies from one individual to the next (skin tone,eye color or hair color)? a.organism b.trait c.character