Biology Terms Section 1-6 VERY DIFFICULT

Organization

Life is organized into increasingly complex levels, from molecules to the biosphere.

Emergent properties

New properties that arise from interactions among components at higher levels of biological organization.

Genetic information

Information stored in DNA that directs cell activities and is transmitted during reproduction.

Energy and matter

Organisms require energy to carry out life processes; energy flows and matter cycles.

Biological interactions

Interactions among biological components and between organisms and their environment.

Evolution

Descent with modification that explains the unity and diversity of life.

Cells

The fundamental units of structure and function in living organisms.

Gene expression

The process by which information in DNA is used to produce RNA and proteins.

Descent with modification

The idea that organisms descended from common ancestors and change over generations.

Unity of life

Shared characteristics among organisms inherited from common ancestors.

Diversity of life

Differences among species produced by evolutionary change.

Natural selection

The process by which advantageous heritable traits become more common through generations because their carriers have greater reproductive success.

Adaptations

Advantageous traits that help organisms survive or reproduce in their environment.

Evolutionary trees

Diagrams illustrating evolutionary relationships and branching points from common ancestors.

Three domains of life

Bacteria, Archaea, and Eukarya.

Scientific inquiry

The process of investigating questions through observations, hypotheses, predictions, and experiments.

Inductive reasoning

Using specific observations to develop general conclusions.

Deductive reasoning

Using general principles to develop specific, testable predictions.

Hypothesis

A proposed explanation that leads to testable predictions.

Scientific theory

A broad, well

Controlled experiment

An experiment in which conditions are controlled so the effect of a particular variable can be investigated.

Independent variable

The variable deliberately changed by the researcher.

Dependent variable

The variable measured to determine the effect of the independent variable.

Control variables

Factors kept constant during an experiment.

Carbon

The backbone of biological molecules because it can form four covalent bonds.

Covalent bond

A chemical bond formed when atoms share electrons.

Carbon skeleton

The chain or arrangement of carbon atoms forming the backbone of an organic molecule.

Hydrocarbons

Molecules composed of carbon and hydrogen.

Hydrophobicity

The tendency of a substance to avoid interacting with water.

Isomers

Molecules with the same molecular formula but different structures.

Structural isomers

Isomers that differ in how their atoms are connected.

Cis

trans isomers

Enantiomers

Molecules that are nonsuperimposable mirror images of each other.

Functional groups

Specific groups of atoms that influence the chemical properties and reactivity of biological molecules.

Phosphate group

A functional group containing phosphorus and oxygen that plays important roles in biological molecules and ATP.

Monomer

A small molecular subunit that can join with other subunits to form a polymer.

Polymer

A large molecule formed from repeating or linked smaller molecular subunits.

Dehydration reaction

A reaction that joins molecules by removing a molecule of water.

Hydrolysis

A reaction that breaks a chemical bond by adding water.

Carbohydrates

Biological molecules used for energy and structural support.

Monosaccharides

Single sugar molecules that serve as carbohydrate building blocks.

Disaccharides

Carbohydrates made of two monosaccharides joined together.

Polysaccharides

Carbohydrates made of many linked monosaccharides.

Storage polysaccharides

Polysaccharides used to store energy.

Structural polysaccharides

Polysaccharides that provide structural support.

Glycosidic linkage

A covalent bond joining sugar molecules.

Lipids

Hydrophobic biological molecules that include fats, phospholipids, and steroids.

Triglycerides

Fats composed of one glycerol molecule and three fatty acids.

Glycerol

A three

Fatty acids

Molecules with a hydrocarbon chain and a carboxyl group that are components of many lipids.