D. Observe how coral colonized a sunken ship. Ecologists look at how a whole ecology develops and maintains itself, so in this case, the coral on the sunken ship would be a whole ecology and the person studying it would be an ecologist.
An exponential growth graph looks pretty much like the right side of a parabola. The graph equation is f(x)= C ·a^x, so you can also plug in x values to find the y value. It's not a linear line, but it curves upwards starting from (0,0).
ATP molecule functions as the power source for a cell. Sometimes it is compared to a battery, which is a pretty fair analogy, but it is more mobile and flexible in its functions than a battery is.
Exocrine glands release secretions outside of the body.
One way to remember this is:
exo = outside
endo = inside
An example of an exocrine gland is a sweat gland. They release sweat (an excretion) to the outside of your body.
I hope this helps! I'm happy to answer any other questions you might have :)