One organism that exhibits all three modes of nutrition (saprophyte, parasitic, and holozoic) is the fungus, Candida albicans.

Saprophytic mode of nutrition:
Candida albicans can survive on dead and decaying organic matter, making it a saprophyte. It decomposes organic material by secreting enzymes that break down complex molecules into simpler ones that can be absorbed by the fungus.

Parasitic mode of nutrition:
Candida albicans can also act as a parasite, living on the surface of host organisms and feeding on their nutrients. For example, it can cause infections such as thrush in humans by growing on the mucous membranes of the mouth and throat.

Holozoic mode of nutrition:
Candida albicans can also obtain nutrients by consuming other organisms. It is capable of phagocytosis, which is the process of engulfing and digesting other cells. This mode of nutrition is more common in the early stages of Candida albicans development, when it is still a single-celled organism.

In summary, Candida albicans is an organism that can exhibit all three modes of nutrition: saprophytic, parasitic, and holozoic. By being able to obtain nutrients from different sources, it is able to survive in a variety of environments.