Campbell Biology - Chapter 1 & 2.

99 flashcards (page 51-92 of campbell)

Biology

The scientific study of life and living organisms.

Emergent Property

A novel characteristic that appears at a higher level of organization but is absent at lower levels.

Reductionism

An approach that simplifies complex systems into smaller, more manageable components for study.

Systems Biology

The exploration of biological systems by analyzing interactions among their parts.

Cell Theory

The concept that all living organisms are composed of cells, the basic unit of life.

Prokaryotic Cell

A cell lacking a nucleus and membrane-enclosed organelles; found in Bacteria and Archaea.

Eukaryotic Cell

A cell containing a nucleus and membrane-bound organelles; characteristic of plants, animals, fungi, and protists.

Organelle

A specialized, membrane-enclosed structure within a eukaryotic cell.

DNA (Deoxyribonucleic Acid)

The molecule that stores genetic information in all living organisms.

Gene

A unit of hereditary information consisting of a specific nucleotide sequence in DNA.

Gene Expression

The process by which information encoded in DNA directs protein or RNA synthesis.

Genome

The complete set of an organism’s genetic material.

Proteome

The entire set of proteins produced by a cell, tissue, or organism.

Proteomics

The large-scale study of proteins and their properties.

Bioinformatics

The use of computational tools to store, organize, and analyze biological data.

High-Throughput Technology

Advanced methods that allow rapid analysis of many biological samples simultaneously.

Negative Feedback

A regulatory mechanism in which the end product slows or stops its own production.

Positive Feedback

A regulatory mechanism in which the end product speeds up its own production.

Evolution

Descent with modification; the process that accounts for the diversity and unity of life.

Natural Selection

The mechanism of evolution in which heritable traits that enhance survival and reproduction become more common.

Adaptation

An inherited trait that increases an organism’s chance of survival and reproduction.

Common Ancestor

A shared predecessor species from which different species have evolved.

Domain

The highest taxonomic category, above kingdom; the three are Bacteria, Archaea, and Eukarya.

Bacteria

A domain of prokaryotic organisms characterized by diverse metabolic and genetic properties.

Archaea

A domain of prokaryotes often found in extreme environments and genetically distinct from bacteria.

Eukarya

The domain that includes all eukaryotic organisms.

Kingdom Plantae

The eukaryotic kingdom consisting of multicellular, photosynthetic organisms—plants.

Kingdom Fungi

The eukaryotic kingdom of organisms that absorb nutrients from outside their bodies.

Kingdom Animalia

The eukaryotic kingdom comprising multicellular organisms that ingest other organisms.

Protist

Mostly unicellular eukaryotes that do not fit into the plant, animal, or fungal kingdoms.

Hypothesis

A testable explanation for a set of observations.

Theory (Scientific)

A broad explanation supported by a large body of evidence and capable of generating new hypotheses.

Scientific Method

A logical, systematic approach to answering scientific questions through observation and experimentation.

Inductive Reasoning

Logic that derives general principles from specific observations.

Deductive Reasoning

Logic that makes specific predictions from general premises; often expressed as "if…then" statements.

Controlled Experiment

An experiment in which an experimental group is compared with a control group that differs in only one variable.

Independent Variable

The factor that is manipulated by the researcher in an experiment.

Dependent Variable

The factor that is measured and observed in response to the independent variable.

Control Group

The group in an experiment that does not receive the experimental treatment.

Experimental Group

The group in an experiment that receives the treatment being tested.

Model Organism

A species used for extensive research because it is easy to grow and has experimental advantages.

Radioactive Isotope

An isotope whose nucleus decays, giving off particles and energy.

Radiometric Dating

A method of determining the age of fossils by measuring the decay of radioactive isotopes.

Climate Change

Long-term directional change to the global climate, including global warming and altered weather patterns.

Feedback Regulation

The modulation of a biological process by its own output.

Atom

The smallest unit of matter retaining the properties of an element.

Element

A substance that cannot be broken down to other substances by chemical reactions.

Compound

A substance formed by two or more elements in a fixed ratio.

Essential Element

An element required for an organism to survive, grow, and reproduce.

Trace Element

An element required by organisms in minute quantities.

Atomic Number

The number of protons in an atom’s nucleus; defines the element.

Mass Number

The total number of protons plus neutrons in an atom’s nucleus.

Isotope

Atoms of the same element that differ in neutron number and mass.

Dalton

A unit of atomic mass approximately equal to the mass of one proton or neutron.

Electron Shell

An energy level representing the distance of an electron from the nucleus.

Valence Shell

The outermost electron shell of an atom, containing the valence electrons involved in bonding.

Valence Electron

An electron in the outermost shell that can participate in chemical bonding.

Orbital

A three-dimensional region around a nucleus where an electron is likely to be found.

Potential Energy

Energy stored due to an object’s position or structure.

Electronegativity

An atom’s attraction for shared electrons in a covalent bond.

Covalent Bond

A chemical bond formed by the sharing of a pair of valence electrons.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between atoms.

Polar Covalent Bond

A covalent bond in which electrons are shared unequally, creating partial charges.

Ionic Bond

A chemical bond resulting from the attraction between oppositely charged ions.

Ion

An atom or molecule with an electrical charge due to loss or gain of electrons.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Hydrogen Bond

A weak attraction between a hydrogen atom carrying a partial positive charge and an electronegative atom with a partial negative charge.

van der Waals Interaction

Weak attractions between molecules or parts of molecules resulting from transient local partial charges.

Chemical Reaction

The making and breaking of chemical bonds leading to changes in the composition of matter.

Reactant

A starting material in a chemical reaction.

Product

A substance formed as the result of a chemical reaction.

Chemical Equilibrium

The state in which forward and reverse reactions occur at the same rate, with no net change in concentration of reactants and products.

Molecule

Two or more atoms held together by covalent bonds.

Valence

The bonding capacity of an atom, usually equal to the number of unpaired electrons required to complete its shell.

Energy Level

The specific amount of energy an electron has, associated with its electron shell.

Essential Themes of Biology

Core ideas—Organization, Information, Energy & Matter, Interactions, Evolution—that unify biological understanding.

Energy Flow

The one-way movement of energy through an ecosystem, entering as light and exiting as heat.

Chemical Cycling

The circulation of matter through ecosystems via biological, geological, and chemical processes.

Genetic Code

The universal set of nucleotide triplets encoding amino acids in protein synthesis.

Messenger RNA (mRNA)

RNA molecule that carries genetic information from DNA to the ribosome.

Amino Acid

The building block of proteins; contains an amino group, carboxyl group, and side chain.

Protein

A functional biological molecule composed of one or more polypeptides folded into a specific shape.

High Specificity

The property allowing biological molecules to interact only with certain other molecules due to shape complementarity.

Experimental Variable

Another term for independent variable; the factor deliberately changed in an experiment.

Statistical Significance

A measure indicating that experimental results are unlikely to have occurred by chance.

Scientific Consensus

The shared conclusion of many scientists, based on extensive evidence and repeated testing.

Climate Warming

The long-term increase in Earth’s average surface temperature due to human activities.

Model

A representation of an object or process used to understand and communicate scientific concepts.

Endorphin

An endogenous signaling molecule that binds brain receptors to reduce pain and produce euphoria.

Morphine

An opiate drug that mimics endorphins by binding to the same brain receptors.

Serpentine Soil

Soil rich in heavy metals where only specially adapted plant species can thrive.

Microscopy

The use of microscopes to view objects and areas of objects that cannot be seen with the naked eye.

Chloroplast

A plant organelle that captures light energy and converts it to chemical energy via photosynthesis.

Photosynthesis

The process by which plants convert light energy, CO2, and water into glucose and oxygen.

Cell Division

The process by which a cell reproduces by splitting into two daughter cells.

CRISPR

A genome-editing tool allowing precise alteration of DNA sequences (mentioned in context of DNA manipulation technologies).

Peer Review

The evaluation of scientific work by others working in the same field to ensure quality and validity.

Collaboration

Cooperative scientific effort in which researchers share data, ideas, and resources.

Technology

The application of scientific knowledge for practical purposes.