Biology Concepts Flashcards

Characteristics of Living Organisms

• Composed of cells, the basic unit of life.
• Exhibit complexity and order in structure.
• Ability to respond to environmental stimuli.
• Capable of growth, development, and reproduction.
• Obtain and utilize energy for metabolic processes.
• Maintain homeostasis, or internal balance.
• Adapt over time through evolutionary processes.

Hierarchical Organization of Living Systems

• Structured levels: cellular, organismal, populational, ecosystem, and biosphere.

Three Domains of Life

• Bacteria: Single-celled prokaryotes.
• Archaea: Single-celled prokaryotes with distinct biochemistry.
• Eukarya: Organisms can be single-celled or multicellular eukaryotes.

Unity Among Living Forms

• All life is based on cells and shares the same genetic code (DNA and RNA).
• Similar metabolic pathways and enzymatic processes across species.
• Commonalities in cellular structure among diverse organisms.

Evolutionary Concepts

• Charles Darwin described evolution as "descent with modification."

Reasoning in Scientific Inquiry

• Deductive reasoning: Uses general principles to forecast specific outcomes.
• Inductive reasoning: Begins with specific observations to form general conclusions.

Scientific Method Steps

• Observation leads to hypothesis formation.
• Predictions are made based on hypotheses.
• Controlled experimentation tests the hypotheses.
• Conclusions drawn from experimental results.

Hypotheses in Experimentation

• A hypothesis provides a potential explanation and must undergo validation through testing.
• Must be carefully designed to isolate one variable at a time, including both test and control groups.

Predictions in Hypothesis Testing

• Hypotheses generate predictions that can validate or invalidate the original hypothesis.

Understanding Scientific Theories

• Scientific theory encompasses interconnected concepts, heavily supported by experimental evidence and reasoning.
• Theories evolve with new information and are continually reassessed for accuracy.

Unifying Themes in Biology

• Cell theory: All living organisms consist of cells, life's fundamental units.
• Evolution: Diversity stems from common ancestry, dating back 3.5 billion years.
• Structure and Function: Structural analysis informs functional understanding and vice versa.
• Molecular Basis of Inheritance: DNA sequences encode organismal information, critical for life's continuity.
• Cells as information-processing systems: Cells process and relay genetic information.
• Nonequilibrium state: Living systems require a constant energy supply and exhibit emergent properties at various levels.

Molecular Genetics

• Gene: A discrete unit of genetic information.
• Genome: The complete set of DNA instructions governing an organism.

Energy and Living Systems

• Living systems are open systems reliant on continuous energy influx.
• Emergent properties arise from the interaction of molecules, cells, and individuals, showcasing the complexity of biological systems.