Biology 120 - u1 p1

Introduction to Biology

  • Course overview and requirements

    • First lecture PowerPoint to be downloaded or opened for note-taking

    • Class formats: physical notebook for notes is acceptable

  • Instructor's commitment to thorough explanations

    • Encouragement for questions: "please do not hesitate to raise your hand"

    • Acknowledgment of speaking speed and willingness to repeat information

Chapter 1: What is Biology?

  • Definition of Biology

    • "Biology is the study of life or the science of how life works."

    • Encompasses all living things: from largest organisms to smallest microorganisms, and cellular levels.

  • Methodology in studying biology

    • Focus on molecular level

    • Introduction to scientific process discussed in the first lab (Bio 120 Lab)

Scales of Biological Understanding

  • Different scales or viewpoints in biology include:

    • Molecular level: focuses on cells and their components

    • Example: Cytology - the study of cells

    • Organs and Tissues: analyzed in nursing and medical tracks

    • Individual organisms: internal structures and reactions to environment

    • Ecological scale: interactions among living things and between them and their environment

Properties of Living Organisms

  • Key properties defining all living things

    • Discussion prompting students to consider what makes organisms alive

  • Six major properties of living things:

    1. Metabolism

    • All living things undergo metabolism—energy conversion for maintenance and growth.

    • Includes cellular respiration, which is vital for energy production.

    1. Complexity and Organization

    • Living organisms are carbon-based with organized cellular structures representing complexity.

    1. Growth and Development

    • Organisms grow from embryos to adulthood, a structured developmental process.

    1. Reproduction

    • Ability to reproduce either asexually or sexually.

    1. Adaptability and Evolution

    • Organisms can adapt over time to changes in their environment, supporting evolutionary processes.

    1. Response to Stimuli

    • Living organisms react to environmental changes.

Comparison with Nonliving Objects

  • Laws of physics govern both living and nonliving entities:

    • Examples: Gravity, Newton's laws, and conservation of energy principles.

  • Structural differences between living and nonliving things:

    • Both composed of elements, but the composition and organization differ significantly.

Essential Elements for Life

  • Four major elements that are essential for living organisms:

    1. Carbon

    2. Hydrogen

    3. Oxygen

    4. Nitrogen

  • Importance of these elements for cell structure and function.

Domains of Life

  • Three primary domains:

    1. Bacteria

    • Diverse group; includes many species, such as E. coli, some helpful for digestion.

    1. Archaea

    • Simple, often live in extreme environments (e.g., hydrothermal vents).

    1. Eukarya

    • Includes complex life forms: animals, plants, fungi, etc.

    • Organisms belonging to this domain are generally more complex and multicellular.

Tree of Life

  • The hierarchical classification:

    • Domains are subdivided into kingdoms, which further branch into orders and families, down to species.

Observations and Questions in Biology

  • Importance of observations in biology, as seen in the works of Charles Darwin.

  • Darwin’s contributions:

    • Observations from the Galapagos Islands on variations among species, notably birds (finches).

    • Propounded the theory of Natural Selection – organisms best adapted to their environments survive and reproduce.

    • Concept of descent with modification: favorable traits are inherited over generations.

Ecology: Interactions of Organisms with Environment

  • Definition: The study of organisms and their environments.

  • Importance of ecological interactions in shaping evolution over time.

  • Examples of human interactions with various habitats and their ecological implications.

Cell Biology

  • Fundamental unit of life: all organisms made of cells.

  • Division into:

    • Unicellular organisms: Single-celled, e.g., bacteria.

    • Multicellular organisms: Composed of numerous cells with specialized functions.

  • Key principle: Structure influences function.

    • Example: basketball compared to cell shapes influencing their functional roles.

Features of Cells

  • Plasma Membrane:

    • Functions as a barrier to protect the cell and regulate internal and external environments.

  • Storage and Transmission of Information:

    • The role of the nucleus containing DNA, which holds genetic information crucial for cell function and replication.

  • Energy Utilization:

    • Cells use energy from the environment, applying Newton's first law of thermodynamics in energy transformations.

Cell Membranes

  • Purpose of cell membranes:

    • Protection and selective permeability separating internal environments from external.

  • Comparison: Single membrane in eukaryotic cells vs. multiple membranes for organelles in eukaryotic and prokaryotic cells.

  • Eukaryotic Cells:

    • Larger, complex cells with membrane-bound organelles and a nucleus.

    • Includes animal and plant cells.

  • Prokaryotic Cells:

    • Smaller, simpler structures without membrane-bound organelles or a defined nucleus.

    • Example organism: E. coli (bacterium).

Conclusion and Next Steps

  • Reminder of upcoming class topics: cell structures and processes.

  • Homework for students to attend scheduled Supplemental Learning Activities (SLA).