In most ecosystems, all or almost all energy in the carbon compounds will originally have been harvested by photosynthesis in producers.
Answer:a. A timer to signal how long to brush teeth
Explanation:
Stimulus control of behavior occurs when the performance of a particular behavior is controlled by the presence or absence of a discriminative stimulus. For example, the presence of a stop sign (a discriminative stimulus) at a traffic intersection increases the probability that "braking" behavior will occur.
Answer:
physical and chemical reactions
Explanation:
To decrease the immune system's response to a transplanted organ