The Organization of Living Things By: Mr. P 7th Grade Life Science Godley Station School

The benefits of being multicellular! You are a multicellular organism!!! Multicellular organisms grow by making more small cells not by making larger cells. Example: An elephant is bigger than you, but your cells are about the same size as an elephant’s cells. The difference is that an elephant has more cells than you.

Larger Size Many multicellular organisms are small, but they are usually larger than single celled organisms. >

Longer Life The life span of a multicellular organism is not limited to the life span of any single cell in your body.

Specialization Each type of cell has a particular job. Example: Heart muscle cells contract and make the heart pump blood.

Cells working together Tissue: A group of cells that work together to perform a specific job. Example: Cardiac muscle tissue is one type of tissue in the heart.

Animal tissues vs. Plant tissues Animal tissues: Nerve tissue, muscle tissue, connective tissue, and protective tissue Plant tissue: Transport tissue (moves water and nutrient), protective tissue (protects the plant and retains water), and ground tissue (where photosynthesis occurs).

Tissues working together Organ: A structure made up of two or more tissues working together to perform a function. Example: Your heart is an organ (The heart is made up mostly of cardiac muscle tissue) Your stomach is another organ. (muscle tissues make food move in and through the stomach) The brain, intestines, and lungs are other organs in your body.

Tissues working together Plants also have organs. Example: A leaf is a plant organ that contains tissues that trap light energy. Other organs in plants are stems and roots.

Check on learning! Describe 3 organs and how tissues help them function. (You can describe plant or animal organs for this answer)

Check on learning answer! Muscle tissue in the stomach helps move food in and through the stomach. Plants use their leaves to trap light energy. Cardiac muscle tissue helps the heart pump blood.

Organs working together Organ system: A group of organs working together to perform a function. Example: The digestive system is made up of several organs such as the intestines and stomach. The digestive system breaks down food into small particles (parts of the body use these small particles as fuel) The digestive system depends on the respiratory system and cardiovascular systems for oxygen.

Levels of organization in the Cardiovascular system Cells form tissues Tissues form organs Organs form organ systems Organs systems form organisms like you!

List the levels of organization in living things. Check on learning! List the levels of organization in living things.

Check on learning answers Cell, tissue, organ, and organ systems

Structure and Function In organisms structure and function are related. Structure: the arrangement of parts in organisms. Function: Is the job that part does. Example: Structure : The structure of the lungs is a large sac. Function: The lungs have tiny air sacs that are called Alveoli. Blood vessels are wrapped around the alveoli and oxygen from air enters into the blood vessels through the alveoli. Blood then brings the oxygen to other body tissues. Carbon Dioxide leaves the blood through the alveoli as well.