(a) Most plants have autotrophic mode of nutrition, [ as they prepare their own food by photosynthesis.
(b) The raw materials used for this are carbon dioxide and water in the presence of solar energy and chlorophyll. Some higher plants are heterotrophic.
(c) Some occur as partial or total parasites on other plants, e.g., Cuscuta, Viscum etc. Some plants are insectivorous which feed on insects to compensate nitrogen deficiency.