The process by which a living organism becomes more mature and complex.

• A. Development
• B. Theory
• C. Experimental Group
• D. Homeostasis

Answer: (A)

Development is the process by which a living organism becomes more mature and complex. As development unfolds, an organism grows in size and its cells differentiate into specialized tissues and organs, forming advanced body systems and functions. This progression is guided by genetic instructions and influenced by environmental factors, enabling transitions from early life stages to adulthood. For example, cells organize into muscle, bone, nerve, and organ tissues, creating coordinated systems that support growth, metabolism, and reproduction. This term specifically captures the idea of increasing maturity and complexity, whereas other terms describe explanations (theory), stability mechanisms (homeostasis), or groups used in experiments (experimental group).