Answer: a community
Explanation:
an organism is one
a community is a small group
a niche is what the animal does
a population is the entire species
Answer: A system is a group of interrelated interacting, or interdependent parts that for a complex whole. A system is a group of interrelated interacting, or interdependent parts that for a complex whole.
Explanation:
Glucose is the only sugar that the human body can use for production of energy, thus any other sugar that enter the body must first be converted to glucose before it can be metabolized through the glycolytic pathway.
In the body, sucrose will first be broken down into glucose and fructose, the glucose will enter the glycolytic pathway while the fructose will be converted to glycogen and send to the liver.
When glucose is inadequate in the body system, the glycogen in the liver will be converted into glucose and it will enter into the glycolytic pathway.
Energy holds them together.
It is a perfect example of a natural selection.
(I'm not sure if this is the exact answer that you are looking for.)