The correct answer is - Their livelihoods are derived from the land.
People in Sub-Saharan Africa are predominantly working in agriculture. They produce most of their food, so their well being is heavily influenced by what they can produce. When an environmental issue occurs, it causes lots of problems, but most importantly hunger. They are producing vegetables, crops and fruits in a primitive manner, are not financially capable to protect their plants, so any major environmental issue is a catastrophe for them. <span />
The hydra has a nervous system characterized by a nerve net. A nerve net is a collection of separate, but "connected" neurons. Neurons are connected by synapse. Communication between neurons can be in both directions at the synapse within a nerve net. The nerve net is concentrated around the mouth. Unlike higher animals, the hydra does not have any grouping of nerve cell bodies. In other words, there are no ganglia.
The hydra does have specialized cells for touch and chemical detection though.
There are two types of environment
well i can say for sure that it dose not steadily increase. the troposphere gets colder as you ascend so its the exterior temperature slowly decreases. (apex)
