A stretched sheet of plastic wrap transmits light but not water waves. Heat is a form of energy often produced by conversion from other forms, as can easily be demonstrated by the warming of a dark object exposed to sunlight. Energy is required when work is done is done on a system or when matter changes its form. Through Six Energy passes through ecosystems in food chains mainly in the form of the chemical energy supplied to each organism by the nourishment it consumes. All organisms convert some of this energy into heat.
Animals also convert some of it into mechanical energy.
Green plants convert light energy into chemical energy by means of the photochemical process called photosynthesis. Reading and Writing From Colordao Draft Model Content Standards. Final Discussion Draft. Standards and Assessment Council, Denver, Colorado. Students write and speak for a variety of purposes and for diverse audiences.