The passage describes how different organisms are classified into groups. Complete the passage by writing a suitable word or words in each of the spaces. Fungi are organisms that are not able to carry out photosynthesis. Their body is usually organised into a mycelium made of thread-like structures called (1) _____________. They have cell walls made of (2) _____________. They feed by absorbing nutrients after secreting extracellular enzymes onto food; this method of feeding is called (3) _____________ nutrition. Like animals, they store carbohydrate as (4) _____________. Protoctists are microscopic single-celled organisms. Some, like Amoeba, live in pond water and have features like an animal cell, while others, like Chlorella, have chloroplasts and are more like plants. A well-known pathogenic protoctist is Plasmodium, which is responsible for causing (5) _____________. Viruses are small, non-living particles. They can only reproduce inside (6) _____________ cells. They do not have a cellular structure, but instead possess a protein (7) _____________ surrounding their genetic material, which can be either (8) _____________ or RNA. An example of a plant virus is the tobacco (9) _____________ virus, which limits crop growth. Any virus that causes disease in its host is described as a (10) _____________.