The repeated movement of certain substances between organisms and the atmosphere is called a(n) A. biogeochemical cycle.
B. evaporation cycle.
C. nitrate cycle.
D. Abiotic cycle.

If a cell is placed into a hypertonic environment,what will happen to it ? a)it will shrink or shrivel b)nothing c)it will burst d) it will expand or enlarge

1. in what ways have non-native species been beneficial? 2. what are some of the hypotheses for the collapse of honeybee colonies? 3. distinguish between regional and functional extinction. 4. why is it difficult to measure background extinction rates? 5. what three factors are most important in causing extinction rates to climb?

This is a membrane-bound, disk-shaped compartment inside chloroplasts and cyanobacteria. they are the site of the light-dependent reactions of photosynthesis.