properties of life

Characteristics of Living Organisms

  • Organized structures consisting of one or more cells.

  • Inside each cell, atoms make up molecules, vital for cellular function.

  • Living organisms can trigger physical or behavioral changes to adapt to their environment.

Reproduction

  • Single-celled organisms: Reproduce by replicating DNA and dividing into 2 new cells.

  • Multicellular organisms: Produce specialized reproductive cells that form new individuals.

Growth and Development

  • Organisms grow and develop according to genetic instructions encoded in their DNA.

  • Young species display characteristics similar to their parents as they mature.

Adaptation and Evolution

  • Organisms exhibit a "fit" to their environment, leading to evolutionary changes in population traits.

  • Example: Thermophilic bacteria thrive in high-temperature environments.

Properties of Life

  • Order

    • Living organisms are composed of cell components or organelles.

    • Advantage of Multicellularity: Specialized cells perform specific functions, forming organs (e.g., heart, lungs).

  • Response to Stimuli

    • Movement toward a stimulus signifies a positive response (e.g., phototaxis in plants).

    • Examples:

      • Plants bend toward light sources.

      • Bacteria can move away from chemicals or light.

      • Mimosa pudica: A plant that folds when touched due to sensitivity (chemotaxis).

  • Reproduction

    • DNA (DeoxyriboNucleic Acid) is essential: contains genes passed to offspring.

  • Adaptation

    • Enhances reproductive potential.

    • Characteristics may change based on environmental modifications.

Complex Nature of Organisms (Page 2)

  • Even small organisms are complex, requiring numerous regulatory mechanisms for internal function coordination:

    • Metabolic processes maintain constant internal conditions.

    • Organisms utilize energy sources for metabolic activities.

Regulation

  • Involves:

    • Nutrient transport.

    • Response to stimuli.

    • Coping with environmental stress.

  • Example: Circulatory system carries oxygen; digestive system removes wastes.

Homeostasis

  • Defined as a “steady state.”

    • Conditions within cells:

      • Proper temperature.

      • pH levels.

      • Pressure.

      • Chemical concentration adjustments.

Energy Processing

  • Some organisms capture solar energy and convert it to chemical energy (food).

  • Others depend on chemical energy from ingested molecules.

Virus: Properties and Life Status (Page 2)

  • An extremely small, infectious agent; metabolically inert, replicates only in living hosts.

  • Note: Antibiotics kill bacteria, but not viruses.

Properties of Life - Pass or Fail?

  • Order: PASS - Organized structures with DNA/RNA arranged for replication.

  • Response to Stimuli: UNKNOWN.

  • Reproduction: MAYBE.

  • Growth: FAIL - Viruses do not grow or develop independently.

  • Adaptation: PASS.

Regulation Status (Page 3)

  • MAYBE/FAIL - Viruses lack membranes and regulatory systems (temp, pH, etc.).

  • They do not consume energy or produce waste.

Energy Processing Status

  • FAIL - Viruses do not possess metabolic pathways.