a) Based on your model and the different functions the cell can do because of all of its different parts, list three reasons why cells are important to an organism.

Cells are fundamental units of life and play several critical roles in the overall functioning of an organism. Here are three reasons why cells are important:

1. Structural Organization: Cells provide the basic structural framework for all living organisms. They form tissues, organs, and systems that work together to carry out complex biological functions. The organization of cells into specialized structures allows for the division of labor, making it possible for the organism to perform various tasks efficiently.

2. Metabolic Functions: Cells carry out essential metabolic processes that are necessary for the growth, energy production, and maintenance of life. They are responsible for converting nutrients into energy (via cellular respiration), synthesizing important biomolecules (like proteins and nucleic acids), and regulating waste removal. These metabolic activities are vital for an organism's survival and proper functioning.

3. Response and Adaptation: Cells can respond to environmental stimuli and adapt to changes in their surroundings. They have the ability to communicate with each other through signaling pathways, allowing for coordinated responses to external factors (such as the immune response to pathogens or the adaptation to temperature changes). This responsiveness is crucial for maintaining homeostasis and ensuring the organism's well-being in a constantly changing environment.

Overall, cells are indispensable for growth, repair, and the overall maintenance of life in organisms.