The Organization of Living Things

By: Mr. P7th Grade Life ScienceGodley Station School

The benefits of being multicellular!You are a multicellular organism!!!a. 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 SizeMany multicellular organisms are small, but

they are usually larger than single celled organisms.

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Longer LifeThe life span of a multicellular organism is

not limited to the life span of any single cell in your body.

SpecializationEach type of cell has a particular job.Example:Heart muscle cells contract and make the

heart pump blood.

Cells working togetherTissue: 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 tissuesAnimal 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 togetherOrgan: 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 togetherPlants 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 togetherOrgan 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!

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

Check on learning answersCell, tissue, organ, and organ systems

Structure and FunctionIn 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.