Which of the following best illustrates the idea of increasing levels of organizational complexity ?

Options

A. Tissue, chemical, cellular, organ, system, organismic
B. Cellular, chemical, tissue, organismic, organ, system
C. Chemical, cellular, tissue, organ, system, organismic
D. Chemical, tissue, cellular, organ, organismic, system

Explanation

To illustrate the idea of increasing levels of organizational complexity, we can break down the biological organization into a sequence that starts from the simplest level and progresses to the most complex. Here’s the step-by-step solution:

### Step 1: Identify the simplest unit of life
- The simplest unit of life is the **chemical** level, which includes atoms and molecules. These are the building blocks of all biological structures.

### Step 2: Move to the cellular level
- When these chemicals come together, they form **cells**. Cells are the basic structural and functional units of life.

### Step 3: Aggregate cells into tissues
- Multiple cells of similar type aggregate to form **tissues**. Tissues are groups of cells that work together to perform a specific function.

### Step 4: Form organs from tissues
- Different types of tissues combine to form **organs**. An organ is a structure composed of two or more types of tissues that work together to perform specific functions.

### Step 5: Create organ systems
- Organs that work together to perform complex functions form an **organ system**. For example, the urinary system includes the kidneys, bladder, and urethra.

### Step 6: Complete the organism
- Finally, all the organ systems together make up a complete **organism**. An organism is a living entity that can function independently.

### Summary of Levels of Organization:
1. **Chemical** (atoms and molecules)
2. **Cell** (basic unit of life)
3. **Tissue** (group of similar cells)
4. **Organ** (composed of different tissues)
5. **Organ System** (group of organs working together)
6. **Organism** (complete living entity)

### Final Answer:
The correct sequence illustrating increasing levels of organizational complexity is: **Chemical → Cell → Tissue → Organ → Organ System → Organism**.

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