I would presume that one of the most complex structures among living things is also one of its most elegantly simple: An aspen forest is amazingly complex in its diversity, but the trees that make it up are actually all one massive single organism. I hope this speaks to the intent of the question.
The most complex structure of all living things are multicellular beings which have evolved in millions of years. an example in Homo Sapiens (us).
The human brain: Its functions are only partly understood
Most Complex Structure in the Universe is Your Brain
All living things are made of at least one cell. The cell is the basic unit of structure and function in living things.
The most genetically complex structure in the human body is the brain.
They do not have the energy needed to react at normal body temperatures.They do not have the energy needed to react at normal body temps.
yes
The most common term for organic molecules found in living things is biomolecules. These molecules include carbohydrates, lipids, proteins, and nucleic acids, which are essential for the structure and function of living organisms.
Water is the most abundant compound in living things, making up about 70% or more of the total mass of most organisms. It is essential for various biological processes and plays a crucial role in maintaining the structure and function of cells.
The most accepted theory regarding the makeup of living things is the cell theory, which states that all living organisms are composed of one or more cells, the basic units of structure and function in organisms.
matrix
Water because most living things depend on it.
Oxygen is the most important factor for living things.
The lake itself is non-living, but most lake have things that live in them.