Explain how cells specialize to form specific tissue and organs?

All cells have the same DNA. They are different because different genes have been locked up and only some of them are expressed. The process began in the embryonic stage, when stem cells are turned into different types of cells by turning off some of the genes. Scientists have been looking for ways to reverse the process, meaning turning specialized cells back into stem cells. Some success has been reported using different methods. The latest one uses a weak acid to stress the cells.

The infrared (ir) and the ultraviolet(uv) represent the two extremities of the visible spectrum (400-700nm). while ir represents electromagnetic radiation with wavelengths longer than those of visible light, uv represents wavelengths shorter than visible light

Well, both latitude and intensity of light affect temperature because, the higher the light intensity, the higher the temperature and since latitude is the measure of how close you are to the equator, then the closer to the equator you are, the higher the temperature is.