Ch 1

Flashcards covering key vocabulary and concepts from the 'Principles of Life' lecture notes, including fundamental biological processes, structure, energy flow, evolution, and scientific methodology.

Photosynthesis

The process by which green leaves of plants transform water and carbon dioxide into sugar and oxygen, storing solar energy in the sugar.

Biology

The scientific study of life, encompassing all living things, or organisms.

Organism

Any living thing; all living things known are descended from a single-celled ancestor.

Common Ancestry of Life

The conclusion that all life has a single origin, descended from one life form that lived nearly 4 billion years ago, evidenced by shared characteristics like nucleic acids, amino acids, and a universal genetic code.

DNA (Deoxyribonucleic Acid)

A nucleic acid molecule that carries genetic information, composed of long sequences of four subunits called nucleotides.

Viruses

Biological entities generally considered part of life; they contain genetic information, mutate, and evolve but are not composed of cells and require host cells to perform most functions.

Cell

The basic unit of life, formed when a membrane surrounds and encloses complex proteins and other biological molecules, allowing concentration and control of chemical reactions.

Prokaryotes

Single-celled organisms that originated early in Earth's history, characterized by genetic material and biochemical structures enclosed within a membrane but lacking a nucleus.

Aerobic Metabolism

A set of chemical reactions that efficiently releases energy from molecules by using oxygen (O2).

Ozone (O3) Layer

A layer in the upper atmosphere formed by the accumulation of O2, which absorbed the Sun's damaging UV radiation and allowed life to move onto land.

Organelles

Membrane-enclosed compartments within eukaryotic cells where specialized cellular functions are performed.

Eukaryotes

Cells or organisms characterized by the presence of a nucleus (containing genetic information) and other membrane-enclosed organelles.

Endosymbiosis

A hypothesis explaining the origin of some organelles (like mitochondria and chloroplasts), stating that smaller cells were ingested by larger cells and evolved a stable partnership.

Multicellularity

The state where cells of some eukaryotes failed to separate after division, remaining attached and allowing for cellular specialization, increased size, and efficiency.

Genome

The sum total of an organism's genetic material, serving as the 'blueprint' for its existence.

Mutations

Changes introduced into an organism's genome during replication, serving as the raw material for evolution.

Domains of Life

The broadest categories of the tree of life, comprising Bacteria, Archaea, and Eukarya.

Second Law of Thermodynamics

A physics principle stating that organized entities tend to become more random if left to themselves, requiring energy to maintain organization in living systems.

Hierarchy of Biological Organization

The structured levels of life from molecules to ecosystems, including small molecules, large molecules, cells, tissues, organs, organ systems, organisms, populations, communities, landscapes, and the biosphere.

Ecosystem

An ecological system where organisms interact with one another and with their physical environment.

System (Biological)

A set of interacting parts (components) in which neither the parts nor the whole can be fully understood without considering the interactions.

Positive Feedback

Occurs in a system when a product speeds up an earlier process, causing the product to be produced faster and faster and tending to destabilize the system.

Negative Feedback

Occurs in a system when a product slows down an earlier process, stabilizing the amount or concentration of the product.

Evolution

Change in the genetic makeup of biological populations through time; a major unifying principle of biology leading to the diversity of life.

Natural Selection

The process described by Charles Darwin where differing survival and reproduction among individuals in a population lead to evolutionary change, favoring traits that increase chances of survival and reproduction.

Adaptations

Structural, physiological, or behavioral traits that increase an organism's chances of surviving and reproducing in its specific environment, resulting from natural selection.

Scientific Theory

In science, a body of scientific work consisting of rigorously tested and well-established facts and principles used to make predictions about the natural world.

Hypothesis

A tentative answer to a scientific question, which must be testable and have the potential of being rejected by observations and experiments.

Controlled Experiment

An experiment that deliberately changes one or more factors (independent variables) in an experimental group and compares the resulting data with an unmanipulated control group, holding all other variables constant.

Independent Variable

The factor that is deliberately manipulated by an investigator in a controlled experiment.

Dependent Variable

The response that is measured in an experiment, which is not manipulated directly but varies depending on the independent variable.