Write the chosen letter on a separate sheet of paper. 1. Which of the following levels of biological organization is considered as the basic unit of life? a. cell c. organ system b. organ d. tissue 2. Which level of biological organization is formed when a group of tissues work together to perform a certain function in the body? a. community c. organ system b. organ d. tissue 3. What level of biological organization is formed when the entire organ system works together? a. biosphere c. population b. organism d. tissue 4. Which among the following is the smallest level of biological organization? a. community c. organism b. organ system d. population 5. What level of biological organization is described as a group of like cells working together for the same function? a. biosphere c. organ system b. cell d. tissue 6. What level of biological organization is made up two or more types of tissue? a. cell c. organ b. community d. population 7. Which among the given levels of biological organization is being referred to as the number of organisms of the same species living in a certain place or area at the same time? a. biosphere C. community​