Describe the meaning of the terms: cell, tissue, organ, organ system and organism as illustrated by examples given in the syllabus

The terms cell, tissue, organ, organ system, and organism represent different levels of biological organization in living organisms. Here’s a description of each term along with examples:

1. Cell

• Definition: A cell is the smallest structural and functional unit of life. It can exist as a single-celled organism or as part of a multicellular organism.
• Example: A red blood cell is a specialized cell responsible for transporting oxygen throughout the body.

2. Tissue

• Definition: A tissue is a group of similar cells that work together to perform a specific function. Tissues are composed of cells that share common characteristics and functions.
• Example: Muscle tissue is made up of muscle cells (myocytes) that contract to facilitate movement.

3. Organ

• Definition: An organ is a structure composed of two or more types of tissues that work together to perform specific functions within an organism.
• Example: The heart is an organ made up of cardiac muscle tissue, connective tissue, and epithelial tissue, all working together to pump blood throughout the body.

4. Organ System

• Definition: An organ system is a group of organs that work together to carry out complex functions necessary for the survival and health of the organism.
• Example: The digestive system includes organs such as the stomach, intestines, liver, and pancreas, all collaborating to break down food, absorb nutrients, and eliminate waste.

5. Organism

• Definition: An organism is any living entity that can function independently. It may be unicellular (composed of a single cell) or multicellular (composed of many cells).
• Example: A human being is a multicellular organism composed of various organ systems working together to sustain life.

Summary

In summary, these terms illustrate the hierarchical organization of life:

• Cells form tissues,
• Tissues combine to create organs,
• Organs work together in organ systems,
• Organ systems make up an organism.