Plants growing towards air that has higher humidity levels are examples of

Phototrophism
There are several starting ingredients that are required for starting the process of photosynthesis. The most important are sunlight, water, carbon dioxide and certain minerals. Sunlight helps in building up the optimum temperature that is required to start the process of photosynthesis. Water is an important raw material that helps to absorb the carbon dioxide from the air.

Idont really understand