Studies the structure, function, and relationship between living organisms.
Examples of living things:
Plants
People
Diversity and Common Characteristics
Living organisms are diverse:
Humans, rabbits, plants, dogs, etc.
Despite diversity, they share common characteristics:
Nostrils, eyes, internal organs (e.g., liver in mammals).
Evolutionarily, organisms are believed to have evolved from a common ancestor:
Cyanobacteria is considered a common ancestor.
Levels of Biological Organization
Biosphere: Largest level, includes land and water.
Ecosystem: Includes large parts like tropical forests and deserts.
Community: Made up of many interacting populations.
Population: Same species living together.
Cell: Basic unit of life.
Tissue: Group of similar cells performing a function.
Organ: Made up of tissues (e.g., lungs, liver).
Organ System: Organs working together (e.g., digestive system).
Organism: Single living entity.
Classification of Organisms
Taxonomy: Discipline of classifying organisms.
Eight levels from most inclusive to least inclusive.
Species: One type of organism.
Genus:
Canis (includes domestic dogs, wolves, coyotes).
Kingdoms:
Protista, Fungi, Plantae, Animalia.
Domains:
Archaea, Bacteria, Eukarya.
Archaea: Live in extreme conditions.
Bacteria: Single-celled, no nucleus.
Eukarya: Have a nucleus, can be unicellular or multicellular.
Scientific Method
Used for explaining observations or experiments.
Five steps:
Observation
Hypothesis
Experiment
Data and Analysis
Conclusion
Example: Fertilizers and Gulf of Mexico
Hypothesis: Excessive nitrogen fertilizers lead to hypoxic zones (low oxygen) causing death in organisms.
Experiment:
Control group: No nitrogen added.
Experimental groups: Different amounts of nitrogen, and a group with pea plants.
Results:
Pea plants naturally enrich soil over time, leading to higher crop yield without pollution.
Initial hypothesis confirmed after analyzing multi-year data.
Conclusion
This lecture covered basic biology concepts including the structure and classification of life, and the application of scientific methods in experiments.