TISSUES, ORGANS & SYSTEMS

• Multi-cellular organisms have many cells that work together in specific ways, each group performing certain functions. When each group does its part, the organism gets everything that it needs. 
• A tissue is a large group of cells that all have the same purpose or function. Each kind of cell has characteristics such as shape, size, flexibility, color, and texture that make it uniquely that kind of cell. Nerve cells combine with other nerve cells to make nerve tissue. Muscle cells combine with other muscle cells to make muscle tissue. Bone cells combine with other bone cells to make bone tissue, and so on.
• An organ is a group of tissues that work together to do a certain job for the body. Some of the human body’s organs include: the stomach, lungs, heart, kidneys, brain, and liver. Some of a plant’s organs include: roots, stems, fruit, and leaves.
•  When several different organs join to meet the organism’s needs, they are letting materials pass in and out of the cells. working together in an organ system. There are several different organ systems constantly working in most multi-cellular organisms. You are probably familiar with some of the human body systems. The respiratory system includes the lungs all the body parts that allow us to breathe in air and exhale carbon dioxide. The circulatory system includes the heart and all the body parts that help move the blood around the body. The blood, in turn, carries nutrients and oxygen to all the cells of the body. The respiratory and circulatory systems work very closely together. The digestive system helps the body get nutrients from food that is eaten, and store energy for future use. The excretory system helps remove waste products that could harm the body otherwise. 
• Each of the body’s systems is necessary for the overall health of the body. Like the body’s building blocks, cells join to make tissues. Tissues join to make organs. Organs join to make systems. It’s all organized to ensure the organism’s survival.
  Name:__________________________________

Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers.

1)   Which statement support the fact that bone cells are smaller than bone tissue?

2)   Why is it necessary for the respiratory and circulatory systems to work together?

3)   Predict what would happen if cell membranes stopped

4)   If you had to prioritize the body systems, which would you say is most important? Why?

5)   Based on what you know about the human body, identify the parts of the respiratory system.