1. Themes in the Study of LIFE
Biology = bios (life)+ logos (study of)
Nino A. Espinas
Biology Unit
PSHS-Main Campus

2. 1. The living world is a hierarchy, with each level of biological structure building on the level below it.
Life is highly organized
Levels of biological organization:
atoms- molecules- organelles- cells- tissues- organs- organ systems- organism- population- community- ecosystem- biosphere
What level/s of bioorganization is/are featured in each item?
1. Gregorio T. Velasquez
National Scientist
Pioneer Scientist in Blue
Green Algae
2. Google Earth

3. 2. Each level of biological structure has emergent properties.
Novel properties emerge that were not present at the simpler levels
“An organism is a living whole greater than the sum of its parts”
Are Emperor penguins (Aptenodytes forsteri) cooperative or selfish?

4. 3. Cells are an organism’s basic units of structure and function.
Cell is the lowest level of structure capable of performing ALL life’s activities
All living things consist of cells
Prokaryotic and eukaryotic cell types
Mitosis- cell division
White blood cells- human macrophage ingesting Candida albicans
Sperms- Sperm race

5. 4. The continuity of life is based on heritable information in the form of DNA
Deoxyribonucleic acid
Substance of genes
Units of inheritance that transmit information from parents to offspring
Nucleotides: A, T, G, C, & U

6. 5. Structure and function are correlated at all levels of biological organization
Form fits function
Biological structure gives us clues about what it does & how it works
Function of a structure provides insight about its construction

7. 6. Organisms are open systems that interact continuously with their environments
An organism is an open system- an entity that exchanges materials and energy with its surroundings.
Nutrient Cycling & flow of E from sunlight to photosynthetic life forms

8. 7. Regulatory mechanisms ensure a dynamic balance in living systems.
Biological processes are self regulating, operating by a mechanism called feedback- in which an output or product of a process regulates that process

9. 8. Diversity and Unity are the dual faces of life on earth.
There is Unity in Diversity in ALL living entities of the Earth
Paramecium cilia
Throat and intestine villi

10. 9. Evolution is the core theme of biology.
Life evolves
Evolution, the process that have transformed life on Earth from its earliest beginnings to its vast diversity today, is the one biological theme that ties together all others
Natural Selection = Differential Reproductive Success

11. 10. Scientific Inquiry
Observation-based discovery and the testing of explanations through hypothesis based inquiry

12. 11.Science, Technology, and Society
Technologies are goal oriented applications of science
Science and technology must promote and improve NOT just human lives, but ALL organisms on earth as well.
An Inconvenient Truth

13. Main References
Campbell NA, Reece, JB, and Mitchell LG Biology. Addison Wesley Longman pp.
Campbell and Reece Biology. Pearson Benjamin Cummings pp.