CHAPTER 1: THEMES OF BIO

Chapter 1: Themes of Biology

Hypothesis

A tentative answer (an educated guess or prediction) to a well-framed question. It must be testable and falsifiable.

Theory

A well-substantiated explanation supported by a large body of evidence, broader in scope than a hypothesis. Example: The Theory of Evolution

Law

Describes an observed pattern in nature without attempting to explain it. Example: The Law of Independent Assortment.

Quantitative Data

Recorded measurements (numerical).

Qualitative Data

Descriptions rather than measurements (non-numerical).

Independent Variable

a variable that can be manipulated/changed

Dependent Variable

The variable that is measured or observed in response to the independent variable (effect). Plotted on the Y-axis.

8 Themes of Biology (Understand What It Means)

New Properties Emerge at Each Level of Biological Organization

Life can be studied at different levels, from molecules to the entire biosphere.

Emergent Properties

New properties that arise with each step upward in the hierarchy of life.

Organisms Interact with Other Organisms and the Physical Environment

Organisms and their environment affect one another.

Life Requires the Transfer and Transformation of Energy and Matter

Energy flows through ecosystems, entering as light and exiting as heat.

Example: Photosynthesis converts solar energy into chemical energy.

Structure and Function Are Correlated at All Levels of Biological Organization

Form fits function in biology.

The Cell Is an Organism’s Basic Unit of Structure and Function

Cells are the fundamental unit of life.

Prokaryotic Cells

No nucleus, simpler.

Eukaryotic Cells:

Have a nucleus and membrane-bound organelles.

Life’s Processes Involve the Expression and Transmission of Genetic Information (DNA)

DNA contains genetic instructions that are inherited by offspring.

From Molecules to Ecosystems, Interactions Are Important in Biological Systems

Positive Feedback

As more product accumulates, the process speeds up (e.g., blood clotting).

Negative Feedback

As more product accumulates, the process slows down (e.g., ATP production regulation).

Evolution:

The Overall Theme of Biology

The study of life

Biology

Natural Selection

Individuals with beneficial traits are more likely to survive and reproduce.

Know the Domains and Order of Groups

Taxonomy

The classification of life.

Three Domains of Life:

Bacteria (prokaryotic)

Archaea (prokaryotic)

Eukarya (eukaryotic, includes plants, fungi, animals, and protists)

Hierarchy of Classification

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species