All living things must face two basic problems. Living things use energy to overcome disorder. Living things combat disorder by taking energy and material from their surroundings and employing them for maintenance, growth, and other survival activities. B. All organisms face the certainty of death. Through reproduction, life continues despite the death of individuals.
Life is defined through a set of observable characteristics.
Genes are parts of DNA molecules. Many mutations are harmful but a few are advantageous. C. Life forms evolve as time passes. All living things arose by descent from a common ancestor as the result of genetic modification taking place in species that lived before them. Individuals in a population vary in many ways, and some of these variations are inheritable.