CH:1 Biology Overview and Scientific Method

What is Biology?.

  • Biology: Scientific study of organisms (structures, life cycles, classification, interactions).

Characteristics of Organisms

  1. Reproduce and Grow: Organisms produce offspring and grow, reaching maturity to reproduce.

  2. Nutrition and Respiration:

    • Plants: make their own food (photosynthesis).

    • Animals: obtain food through feeding; materials used for growth and energy release (respiration).

  3. Detect and Respond to Stimuli (Irritability): Ability to respond to environmental changes; involves movement.

  4. Homeostasis: Maintenance of a stable internal environment; excretion removes metabolic wastes (e.g., CO₂, urea).

Importance of Studying Biology

  1. Appreciation and respect for organisms and the environment.

  2. Development of scientific problem-solving skills.

  3. Understanding health, environmental, and social issues to make informed decisions.

Scientific Method

  • Steps:

    1. Make Observations.

    2. Ask Questions.

    3. Propose a Hypothesis.

    4. Make Predictions.

    5. Test the Hypothesis.

    6. Draw Conclusions.

  • Variables in Experiments:

    • Independent Variable: Factor that is changed.

    • Dependent Variable: Factor that is measured.

    • Controlled Variables: Factors kept the same to ensure fairness.

Nature of Science

  • Key Aspects:

    1. Advances through skepticism.

    2. Requires creativity and imagination.

    3. Involves carefully designed controls.

    4. Ongoing inquiries.

  • Historical examples: Experiments by Redi, Needham, and Spallanzani illustrate scientific process and advances.