The best answer is C - to break down food into nutrients.
The digestive system breaks down food into its simplest form that cell are able to utilize for energy. Food is broken down into its monomer units. Proteins are broken down into amino acids, lipids are broken down into fatty acids and glycerol and carbohydrates are broken down into glucose.
Glucose is then absorbed into the blood and transported to every cell in the body. The cells take in glucose and use it as fuel and raw material in the process of cellular respiration. From one molecule of glucose, 36 to 38 molecules of ATP ( the form of energy used by cells) are produced.
Each organism is unique because of genetic variation. Each set of genes we inherit from our parents codes for a specific trait. And our DNA is a blueprint for these traits. Not everybody contains the same genes and that is why we are all so beautifully unique.
Answer:
The invention of the electron microscope allowed them to see organelles and other structures smaller than cells. There is variation in cells, but all cells have a plasma membrane, cytoplasm, ribosomes, and DNA. These similarities show that all life on Earth has a common ancestor in the distant past
Animal cells do not have a cell wall or chloroplasts but plant cells do. This is just one example there are several ways. <span />
