1) Sugar is classified into which nutritional group? 2) For a unicellular organism to live, what must it do? 3) Give an example of an organism that can cause a contagious disease.

 1) Sugar is classified into the nutritional group known as carbohydrates. Carbohydrates are a major source of energy for the body and are composed of carbon, hydrogen, and oxygen. Sugars like glucose, fructose, and sucrose are simple carbohydrates because they are made up of one (monosaccharides) or two (disaccharides) sugar units.

2) For a unicellular organism to live, it must perform several essential functions, including: - Nutrient uptake: It must obtain nutrients from its environment for energy and growth. - Metabolism: It has to convert those nutrients into energy and necessary compounds through metabolic processes. - Growth: It needs to grow by synthesizing essential components like proteins and nucleic acids. - Reproduction: It must reproduce to ensure the survival of its species, often through processes like binary fission or sometimes more complex forms of sexual reproduction if it has that capability. - Waste elimination: The organism needs to excrete waste products resulting from metabolic processes.

3) An example of an organism that can cause a contagious disease is Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB). It is an infectious disease that primarily impacts the lungs and can be spread through the air when people who have an active TB infection cough or sneeze.