key definitions

• capsid: a protein coat comprising the main structural unit of a virus particle
• cellulose: the carbohydrate that makes up the wall
• chloroplast : organelle found in plant cells and some proctoctist cells that can capture light energy for photosynthesis
• excretion: removal of waste substances that have been produced from chemical reactions inside the body
• genus: taxonomic group containing one or more species
• homeostasis: the maintenance of a constant internal environment in the body
• nutrition: a process by which an organism gets chemicals and energy it needs from its surroundings
• sensitivity: the detection of changes(stimuli) in the surroundings by a living organism and its responses to those changes
• stimulus: a change in environment that triggers the a response in an organism
• cell membrane: a partially permeable membranes that surrounds the cell
• cell wall: an outer layer made of cellulose that strengthens plant cells
• chlorophyll: the green pigment found in chloroplasts that absorb light for photosynthesis
• cytoplasm: a thick solution of salts and water + proteins, within the cell; contains cell's organelles