Homeostatic regulation of the body is made possible through coordination of all body systems. this coordination is achieved mainly by:

The correct answer is- nervous and endocrine systems

Explanation:

Homeostasis is the ability of a system to resist the change and maintains a stable and constant condition. In our body homeostasis occurs due to the coordination of all body systems. Like the kidney which comes in the excretory system helps in maintaining the osmotic balance in blood.

This coordination is achieved mainly by the nervous and endocrine system. Nervous systems coordinate different systems in the body by accepting the signals and releasing the informatory signals to them.

Endocrine system release hormones in the blood that reaches to target organs and regulate their function that helps in maintaining homeostasis in the body.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.