Chapter 1: Intro to Biology

Biology

the scientific study of life, encompassing the investigation of living organisms and their interactions with the environment. It seeks to answer the fundamental question: What is life?

Properties of Life

Living things share several key characteristics

Order

Organized structure, from molecules to cells to organisms.

Reproduction

Ability to produce new individuals.

Growth and Development

Increase in size and change in form during an organism's life cycle.

Energy Processing

Use of energy to power activities and chemical reactions

Regulation

Maintenance of internal stability (homeostasis)

Response to Environment

Reacting to external stimuli

Evolutionary Adaptation

Populations change over generations to better survive in their environments.

The Cell

The cell is the structural and functional unit of life, representing the smallest unit that exhibits all properties of living things.

Domain Bacteria

Composed of prokaryotic cells; found in diverse environments

Domain Archaea

Also prokaryotic; often inhabit extreme environments

Domain Eukarya

Includes all eukaryotic organisms, such as protists, fungi, plants, and animals

Life’s Hierarchy of Organization

Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism → Population → Community → Ecosystem → Biosphere

Emergent properties

New characteristics that appear at each level due to the arrangement and interaction of components.

Science

a systematic way of understanding the natural world through evidence-based inquiry. It relies on observation, experimentation, and analysis.

Scientific Method

Involves making observations, forming hypotheses, making predictions, conducting experiments, and analyzing data.

Scientific Theory

A broad explanation supported by a large body of evidence

Independent Variable

The factor that is changed or manipulated

Dependent Variable

The factor that is measured; depends on the independent variable

Control Group

Used for comparison; does not receive the experimental treatment.

Experimental Group

Receives the treatment or manipulation.

Evolution

 the central theme of biology, explaining both the unity and diversity of life. It is the process by which populations change over time through mechanisms such as natural selection

Natural Selection

Proposed by Charles Darwin; individuals with advantageous traits are more likely to survive and reproduce.

Family History

Each species has a lineage that traces back through ancestral species.

Information Flow

Life depends on the flow of information, primarily through genetic material (DNA), which directs cellular activities and heredity.

DNA

Contains instructions for building proteins.

Gene Expression

 Information from DNA is transcribed to RNA and then translated into proteins.

Regulation

Cells respond to internal and external signals to regulate processes such as blood glucose levels.

Protein Structure

The shape of a protein determines its role (e.g., hemoglobin transports oxygen).

Cellular Structure

Nerve cells have long extensions to transmit impulses over distances.

Energy Flow

Sunlight → Producers (plants) → Consumers (animals) → Heat

Matter Cycling

Elements move from the atmosphere and soil, through living organisms, and back to the environment.

Emergent Properties

New functions and behaviors that result from the organization and interaction of system components.