1. Unit of Structure and Function:
The cell’s structure and function act together providing the homeostatic unit of life.
2. Chemical Basis of Life:
Laws of chemistry apply to living and nonliving systems. These laws include rules by
which ionic and covalent bonds form and are broken. Energy is always involved. Living systems
are uniquely organized as an array of macromolecules that serve as functional units to maintain homeostasis.
3. Energy for Living Systems:
The energy for life primarily derives from the sun. Plants capture energy by absorbing light and using it to
form strong, covalent, chemical bonds between the atoms of organic molecules. In addition, the energy
stored in chemical bonds between the atoms can be used as sources of energy for life processes.
Mendel’s laws explain the inheritance of traits and how they combine to form new genetic combinations.
They explain how new characteristics can result from existing genes or from mutations of genes in
reproductive cells and how these mutations can be inherited through asexual or sexual reproduction.
Modern molecular biology allows scientists to analyze, isolate and alter genes and this ability helps
scientists in the analysis and treatment of certain diseases.
The biosphere is a complex system of interactions among living and nonliving components with matter
and energy moving through different levels of organization. The distribution and abundance of organisms
and populations in ecosystems are ultimately governed by the availability of matter and energy and the ability
of the ecosystem to recycle organic materials. Any changes affecting a component ultimately affect the entire
biosphere including the activities of the human population.
The diversity of life is the result of natural selection in a changing environment and other evolutionary
processes (gradualism and punctuated equilibrium) that have been active for billions of years. Molecular,
anatomical and fossil evidence support the theory of natural selection. Scientists have developed a
classification system to organize the diversity of life. Living things are classified into kingdoms based
on major distinctions among them. Classification systems allow differentiation among organisms and
help distinguish human beingsfrom other primates.
7. Human Biology:
The human body is composed of interacting systems made up of interacting organs, tissues and cells which
are affected by environmental conditions, nutrition, physical activity and pathogens.