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• Biology is the study of life and living things display great diversity.
• Living things are composed of the same chemical elements as nonliving things.
• Living things obey the same physical and chemical laws that govern everything in the universe.

Levels of Biological Organization

• Atoms are the most basic level, composed of electrons, protons, and neutrons.
• Molecules are unions of two or more atoms of the same or different elements,
• Cells are the structural and functional units of all living things.
• Organisms can be unicellular or multicellular
• Tissues are groups of cells with a common structure and function.
• Organs consist of tissues functioning together for a specific task.
• Organ systems are composed of several organs working together.
• An organism comprises multiple organ systems.
• A species are groups of similar, interbreeding organisms.
• A population includes all the members of a species within an area.
• A community is defined as populations interacting within the same environment.
• An ecosystem is a community along with its physical environment
• The biosphere includes all regions of Earth's crust, waters, and atmosphere inhabited by living organisms.
• Biological organization ranges from atoms to the biosphere.
• Each level of organization is more complex than the one preceding it.
• Each level acquires new, emergent properties as biological complexity increases.

The Biosphere

• The biosphere encompasses the zones of air, land, and water where organisms exist.
• An ecosystem includes the community and its physical environment.
• A community consists of interacting populations within a shared environment.
• A population includes all members of a species within a specific area.
• A species is a group of similar, interbreeding organisms.
• Organisms are formed from joined organ systems.
• Organs work together to form an organ system.
• Organs are composed of tissues, which consist of similar cells.
• Molecules combine within a cell to form larger molecules.
• The organization of life begins with individual atoms.

Life Requires Materials and Energy

• Energy is the capacity to do work.
• Energy is required to maintain organization and facilitate life-sustaining processes like chemical reactions.
• Metabolism includes all the chemical reactions occurring within a cell.
• The sun is the primary energy source for Earth.
• Plants, algae, and other organisms capture solar energy and perform photosynthesis.
• Photosynthesis converts solar energy into the chemical energy of carbohydrates.

Ecosystems and Energy Flow

• Ecosystems cycle chemicals and flow energy.
• Chemicals are not used up when organisms die.
• Chemicals move through a food chain from one population to another.
• Chemicals from producers are transferred to consumers and then to decomposers.
• Decomposition returns chemicals to living plants.
• Energy from the sun flows through plants and members of the food chain.
• Energy flows as one population feeds on another.
• A constant supply of solar energy is required.

Characteristics of Living Organisms

• Homeostasis maintains internal conditions within certain boundaries.
• Organisms must maintain biological balance.
• Feedback systems monitor internal conditions and make necessary adjustments.
• Living organisms interact with and respond to environmental changes.
• The ability to respond often results in movement.
• Living organisms reproduce to maintain their population.
• The method of reproduction varies among organisms.
• Organisms pass on their genetic information or genes to the next generation when they reproduce.
• Genes determine the characteristics of an organism.
• Genes are composed of DNA (deoxyribonucleic acid.)
• An adaptation is any modification improving an organism's ability to function in a specific environment.
• The diversity of life results from long-term adaptation to changing environments.
• Evolution occurs when a population of organisms changes over time to become better suited to their environment.

Evolution

• The theory explains the diversity and unity of life.
• All living things descended from a common ancestor.
• Common descent occurs with modification.
• Natural selection occurs through the evolutionary mechanism by Charles Darwin.
• Environmental aspects select traits passed on to the next generation.
• Those who maintain favorable traits reproduce offspring and survive.
• The frequency of favorable traits in a population can be increased by survival.
• Mutations fuel natural selection. Mutations introduce variations among population members

Taxonomy and Classification

• Taxonomy identifies, names, and classifies organisms based on specific rules.
• Systematics studies the evolutionary relationships between organisms.
• Common categories: species, genus, family, order, class, phylum, kingdom, supergroup, and domain.
• Each successive category includes more types of organisms

Domains

• Domain Archaea contains prokaryotes that inhabit extreme environments similar to primitive Earth
• Prokaryotes lack a membrane-bound nucleus.
• Domain Bacteria contains unicellular prokaryotes inhabiting all environments, including skin, mouth, and intestines.
• Domain Eukarya contains unicellular and multicellular eukaryotes.
• Eukaryotes have a membrane-bound nucleus.

Kingdoms and Supergroups

• Domain Archaea and Bacteria: kingdom designations are still in progress.
• Domain Eukarya: kingdoms (Protista, Fungi, Plantae, Animalia) are designated, and new taxonomic supergroups are in progress.
• Some eukaryotic supergroups include Excavata, Chromalveolata, Rhizaria, Archaeplastida, Amoebozoa, and Opisthokonta

Scientific names are:

• Universal and based in Latin.

• The binomial nomenclature consists of a two-part name where:
  • The 1st word is the genus, and always capitalized.
  • The 2nd word is the species designation (or specific epithet).
Written in lowercase.
  • Both words are italicized.

• Examples are:
  • Homo sapiens (humans)
  • Zea mays (corn)

Scientific Method

• It is the procedure for gaining new knowledge through research.
• Five steps: 
  • Observation
  • Hypothesis
  • Predictions and Experiments
  • Data Collection with Statistical Analysis
  • Results and Conclusion

Observations and Hypothesis

• Scientists use their senses to gather information about a phenomenon or natural event.
• A hypothesis is a tentative explanation for observations.
• An example is the discovery of penicillin

• It is developed through inductive reasoning. It is testable

Predictions and Experiments

• Procedure to test a hypothesis. Utilizes deductive reasoning.
• The experimental design is the manner in which a scientist conducts an experiment.
• An experimental design ensures the contribution of a specific variable.
 Also known as the experimental (independent) variable, to the observation.
• A test group is exposed to the experimental variable.
• A control group goes through all aspects of the experiment, but is not exposed to the experimental variable.
• Results should be objective if the same result is shown.

Presenting and Analyzing Data

• Consists of data analysis using statistics.
• Measures of variation
  • Standard error: How the data is off from the average Statistical Data
• Less than 5% is acceptable (p < 0.05).
• The greater the confidence in the results, the lower the p value should be.
• It must not be due to chance 'alone.

Conclusion and Peer Review

• Used to analyze data to determine whether the hypothesis is supported or not.
  • If prediction happens, the hypothesis is supported.
  • The hypothesis is rejected if prediction does not happen.
• Findings are reported in scientific journals.
• Findings are reviewed.
• Scientists attempt to duplicate or dismiss published findings

Theory

• Are concepts that join together two or more well-supported and related hypotheses.
• Supported by a wide range of observations, experiments, and data.
• A scientific principle or law. It is a widely accepted set of theories with no serious challenges to validity.
• Biologic concepts:
  • All organisms are composed of cells; new cells come from pre-existing cells. Homeostasis The internal environment of an organism
stays relatively constant – protective of life.
  • All living organisms have a common ancestor are adapted to a particular way of life.

Hypothesis

•  Antibiotic B is a better treatment for ulcers than antibiotic A.

Study Setup

• One group consists of subjects with ulcers who are not given either antibiotic.
• Two test groups:
  • Subjects with ulcers getting A or B antibiotic.
  • An endoscopy is performed on all subjects to check lining the walls of the stomach. 
• Statisticians determined how valid the treatments were. 
• The theory was supported based on the data.

Science vs Society

• Science is a systematic way of acquiring knowledge about the natural world.
• Technology is the application of scientific knowledge to the interest of humans. 
  • Examples: cell phone, new drugs.

Climate Change

• Refers to changes in the normal cycling of the Earth's climate attributable to human activities.
• Chemical cycle:
  • Burning fuel.
  • Construction of new forest and farmland replacement
• Global warming occurs when Co2 increases.
  • Produced by greenhouse effect