Answer:
Human activities affect the flow of energy and matter in an ecosystem and alter the energy balance in ecosystems through the unsustainable nature of what they do. The energy flow is affected in several ways as a result of pollution, overpopulation, deforestation, burning fossil fuels, etc. Such changes have stimulated soil erosion, climate change, causing water unfit to consume, poor quality of air and so on. When humans cause a change in the energy balance, they impact the ability of the ecosystem to respond and adapt to changes in the environment. It is like getting a cut, but it never heals and grows bigger instead.
A cell is the smallest basic unit of life
The given blank can be filled with the production of endorphins.
The endorphins are the hormones, which are responsible for the activation of the opiate receptors in the body. They are the natural pain killers. The activation of the opiate receptors causes the analgesic effects on the body.
These endorphins are secreted in the brain and the nervous system. The effect of the endorphins is similar to that of the morphine.