Organisms & Living Systems
Oddly perhaps, the definition of life is controversial. The current definition is that organisms are open systems that maintain homeostasis, are composed of cells, have a life cycle, undergo metabolism, can grow, adapt to their environment, respond to stimuli, reproduce and evolve. Viruses are an example of a borderline case. For many years, science considered viruses as sort of non-living poison. Life is a characteristic that distinguishes physical entities that do have biological processes, such as signaling and self-sustaining processes, from those that do not, either because such functions have ceased, or because they never had such functions and are classified as inanimate. Various forms of life exist, such as plants, animals, fungi, protists, archaea, and bacteria. The criteria can at times be ambiguous and may or may not define viruses, viroids, or potential synthetic life as “living”. Some scientists have proposed in the last few decades that a general living systems theory is required to explain the nature of life. Such a general theory would arise out of the ecological and biological sciences and attempt to map general principles for how all living systems work.
Lesson 1 (or “Day 1”) Material
Lesson 2 (or “Day 2”) Material
- Day 2 Instructor Presentation
- Day 2 Student Handout
- Day 2 Rubric
- Read Biology 48 – Trophic levels
- Read Biology 48 – Living systems
- Read Biology 48 – Energy flow (ecology)
- Read Biology Textbook – pages R27–R41
Lesson 3 (or “Day 3”) Material
Lesson 4 (or “Day 4”) Material
Compare Contrast and Debate
Resources Documents and Links
- Digital Asset from cK-12.org (00.04.Cell-Theory)
- Scientific America Are Viruses Alive? web article
Special Notes and Notices
- Science & Engineering Practice: Develop and use models.
- Cross-Cutting Concept: Stability and Change.