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.