In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Question: When different types of tissues work together to perform a unique function, what do they form? Answer: organ
When different types of tissues work together to perform a unique function, they form organ.

Question: What kind of hormones are released into the environment for communication between animals of the same species? Answer: pheromones
Pheromones are released into the environment for communication between animals of the same species.

Question: What is a structure that is composed of one or more types of tissues? Answer: organ
A(n) organ is a structure that is composed of one or more types of tissues.