LT #4 I can describe that cells differentiate to form specialized cells

Human Body Basics BW
• Margy’s argument is the best answer. All
living organisms are made of cells. The cell
is the basic unit of structure in all living
organisms. What is less obvious is that the
cell is also the basic unit of function.
• It is within the cell that most of life’s basic
processes such as getting rid of waste
molecules, growth, repair, movement
Human Body Basics
• In addition to the basic cell functions,
specialized cells in multicellular organisms
perform functions that support life processes.
Ex: muscle cells contract to support
• Specialized cells can be arranged to form
tissues, such as muscle, nerve tissue, and
blood tissue.
• Tissues can be arranged to form organs
• Organs to Organ Systems
LT #4 I can express that cells
differentiate to form specialized cells,
tissues, organs, organ systems, and
Labor of Division
• Within a multicellular (meaning made of more than one
cell, so yourself) organisms there is a division of labor.
• Division of labor means that the work of keeping the
organisms alive is divided among different parts of the
• Each part has a specific job, it works in harmony with all
the other parts.
• The arrangement of specialized parts within a living thing
is sometimes referred to as levels of organization.
Level 1: Cells
• Cells, of course, are the first level of organization.
• In multicellular organisms, many cells are specialized
to perform a specific function for the organism.
• Ex: Muscle Cells, Nerve Cells, Bone Cells, Red Blood
Cells, White Blood Cells, Lung Cells, Etc.
Level 2: Tissues
• In any multicellular organisms, cells rarely work alone.
• Cells that are similar in structure and function that work
together to do a specific job are called tissues.
• Your body, like that of many other animals, is made up of
several types of tissue.
• Ex: Bone cells form bone tissue, a
strong, solid tissue in your body
that gives you shape and support.
Level 2: Tissues
• You also have muscle tissue and nerve tissue that
work together to move your body.
• Cells of the muscle tissue contract or relax to allow
your body to move. But this movement does not
occur until direction is given by cells of the nervous
Level 2: Tissues
• Plants have tissues, too.
• One tissue moves food around the plant to cells that
need it.
• Another tissue carries water up from the plant’s
roots to its leaves.
• Still another plant tissue forms the hard outer
covering of trees known as bark. Bark is a tissue that
acts as a protective covering for woody plants.
Level 3: Organs
• Just as cells join together to form tissues, different tissues join
together to form organs.
• An organ is a structure made up of two or more tissues that work
together to carry out a specific job.
• Ex: Your heart, is an organ made up of muscle tissue, blood tissue,
and nerve tissue.
• Others organs are: Bones, Brain, Spinal Cord, Pancreas, Spleen,
Tonsils, Lungs, Small Intestine, Kidneys, Bladder, Etc.
• Roots, stems, and leaves are three organs found in many plants.
Level 4: Organ Systems
• Organs do not usually work alone. Instead, several
organs work together as an organ system.
• An organ system is made up of all organs that work
together to do a specific job.
• Ex: A plant’s leaves, stems, and roots work together to
make, transport, and store food.
Main Organs Function
Integumentary Skin
Protects the body and
prevents water loss
Movement of the body,
attached to bones
Support and protection
of soft body parts
Brain, Spinal Controls mental and
Cord, Nerves bodily functions
Controls homeostasis by
releasing hormones
Main Organs
Circulatory Heart, Blood
Lymphatic Spleen, Thymus,
Transport of materials to
and from body cells
Remove dead cells and
foreign bodies from body
Respiratory Lungs, Trachea
Exchange of gases
between blood and the
Stomach, Small Break down food for
absorption into the blood
Kidneys, Bladder Control of water balance
and chemical makeup of
Level 5: Organisms
• You are an organism. Dogs and trees are also
• An organism is an entire living thing that carries out
all the basic life functions.
• The organism is the fifth and highest level of
• Organisms are made up of cells, tissues, organs, and
organ systems.
Cells, Tissues, Organs, Organ Systems, and
• By now two things should be clear to you:
• Each level of organization interacts with
every other level.
• The smooth functioning of a complex
organism is the result of all its various
parts working together.
Levels of Organization
Five-Tab Foldable
• For each level

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