The document discusses the organization of cells in multicellular life forms. It explains that cells are organized into tissues that work together to perform specific functions, such as muscle tissue for movement. Tissues then combine to form organs like the skin or lungs. Groups of organs that work together on different body functions are called systems, such as the respiratory, circulatory and excretory systems which are involved in nutrient exchange. The document provides examples of the nutrition, interaction and reproduction functions carried out by systems within the human body.

1. The Mackay School
Fifth Grade 2014
THE ORGANIZATION OF CELLS IN MULTICELLULAR LIFE FORMS
Cells in multicellular life forms are organized and coordinated. Thus, a life is able to
perform all of its functions. Cells interact with each other, but they are not all the
same.
Tissuesare made of a group of cells working together. They develop the same
function. Muscle tissue makes you able to move. Nerve tissue forms the nerves and
the nerves transmit impulses to every part of your body. Epithelial tissue, like the skin,
covers and protects the body.
Organsare formed by different types of tissues.
Systemsare groups of organs working together. It is the most complex organization
within our bodies. Systems work on different functions. These are three of them:
a. The nutrition function, which is carried out by the respiratory system, the
circulatory system and the excretory system. It is a group of processes in
charge of exchanging matter and energy.
b. The Interaction function, which begins with the sense organs gathering
information from the environment, this information is received by the nervous
system. The nervous system processes the information and sends it to the
locomotor and other systems, and these systems react to the signal.
c. The reproduction function, when special cells join together and forma new life
form. This new life form ensures the numbers and characteristics of the species.

2. The Mackay School
Fifth Grade 2014
Analyze
Complete the chart using a where it corresponds.
Life form Number of cells Organization of cells
Unicellular Multicellular Tissues Organs Systems
Elephant
Human
Tiger
Dog
Paramecium
Yeast
Bacterium
What type of cell is represented in the picture? Research and label it.
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