What is the process of an organism growing organically and changing from simple to complex called?

The process of an organism growing organically and changing from simple to complex is referred to as development. This is a fundamental concept in biology that encompasses the various stages an organism undergoes from conception to maturity. During development, a single fertilized egg can differentiate into complex structures, such as tissues and organs, which contribute to the growth and functionality of the organism.

Development includes processes such as cell division, growth, and differentiation, leading to the formation of specialized cells and systems that define the organism's life stages. This process is vital for the individual life cycle of organisms and is a key aspect of how organisms reach their full potential in terms of size, structure, and function.

The other options focus on different aspects of biological processes. Evolution refers to the change in inherited traits of a population over generations. Metamorphosis specifically describes the transformation that certain animals undergo during their life cycle, such as a caterpillar developing into a butterfly. Adaptation involves shifts in traits in response to environmental changes but doesn't specifically encompass the entire growth process from simple to complex. Thus, development is the most accurate term for this process.