Testing for biological molecules — practice question

Read the passage below. The three-toed sloth, $Bradypus\,variegatus$, is a very slow mammal native to Central and South America and spends most of its life in trees. In Fig. 5.1, the sloth’s thick, long grey fur appears green. Its hairs contain grooves where water can gather. Research has shown that this green colour is caused by algae living on the sloth’s fur, with $Trichophilus\,welckeri$ being the most common species. Algae are eukaryotic, photosynthetic organisms. Many other non-photosynthetic eukaryotes, in both unicellular and multicellular forms, have also been found on the sloth’s fur. These include different species of roundworms, insects and saprotrophic fungi.