Explain why, in terms of the distinguishing features of fungi they are not part of the plant kingdom.
Fungi are multicellular organisms which are classified as another kingdom in the biological systems. Some kinds of fungi have "plant-like" resemblance but are completely not related because of certain factors.
The distinguishing factor that puts a demarcation line between fungi and plants is the capability to synthesize or create their own food. Fungi doesn't have photosynthetic organelle that is responsible for creating carbohydrates instead they feed on decaying matters/tissues and other organisms. Fungi do not have true leaves, stems and roots; some fungi. They reproduce via spore formation not the way plants do by seed germination.
First of all,fungi do not have chlorophyll.Chlorophyll is required by plants for photosynthesis.Some fungi are sources of food but they are not autotrophs.Fungi are either saprophytes(live on dead and decaying matter),parasites(suck nutrition from the host) or symbionts.Fungi digest their food by extracellular digestion where the food is digested outside the body by secreting enzymes and then absorbed.Fungi also don't have leaves,roots or stems like plants.Fungi reproduce by spores not seeds.