Biology - Nature of Science

Science

organized way of gathering and analyzing evidence about the natural world

Observation

process of noticing and describing events or processes in a careful, orderly way

Inference

A logical interpretation based on prior knowledge and experience.

Hypothesis

possible explanation for a set of observations or possible answer to a scientific question

Controlled Experiment

experiment in which only one variable is changed

Independent Variable

factor in a controlled experiment that is changed on purpose; also called manipulated variable

Dependent Variable

Factor in a controlled experiment that is observed & changed in response to the independent variable

Control Group

group in an experiment that is exposed to the same conditions as the experimental group except for one independent variable

Data

evidence; information gathered from observations

Theory

well-tested explanation that unifies a broad range of observations

Bias

A particular preference or point of view that is personal, rather than scientific.

Biology

The study of life

DNA

genetic material that organisms inherit from their parents

Stimulus

signal to which organism responds

Sexual Reproduction

cells from two parents unite to form a new organism

Asexual Reproduction

Reproduction involving only one parent resulting in identical offspring

Homeostasis

balance of internal chemical conditions that organisms maintain

Metabolism

the combination of chemical reactions through which an organism builds up or breaks down materials

Biosphere

the part of Earth where life exists

Atom

Basic unit of matter

Nucleus

the center of an atom, which contains the protons and neutrons

Electron

a negatively charged subatomic particle

Element

A pure substance made of only one kind of atom

Isotope

Single element that has the same number of protons but different number of neutrons

Compound

substance formed by the chemical combination of two or more elements in definite proportions

Ionic Bond

Formed when one or more electrons are transferred from one atom to another

Ion

atom that has a positive or negative charge

Covalent Bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

Molecule

smallest unit of most compounds that displays all the properties of that compound

van der Waals forces

a slight attraction that develops between the oppositely charged regions of nearby molecules

hydrogen bond

weak attraction between a hydrogen atom and another atom

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

Mixture

material composed of two or more elements or compounds that are physically mixed together

Solution

All components are evenly distributed

Solute

A substance that is dissolved in a solution.

Solvent

the substance in which the solute dissolves

Suspension

mixture of water and non-dissolved material

pH Scale

scale with values from 0 to 14, used to measure acidity

Acid

solution with a pH less than 7

Base

solution with a pH higher than 7

Buffer

compound that prevents sharp, sudden changes in pH

Monomer

small chemical unit that makes up a polymer

Polymer

large compound formed from combinations of many monomers

Carbohydrate

major source of energy for the human body

Monosaccharides

Single sugar molecules

Lipid

Fat

Nucleic Acid

Found in DNA & RNA

Nucleotide

subunit that makes up nucleic acids

Protein

Needed for growth & repair

Amino Acid

compound with an amino group on one end and a carboxyl group on the other end (make up proteins)

Chemical Reaction

process that changes one set of chemicals into another set of chemicals

Reactant

elements or compounds that enter into a chemical reaction

Product

element or compound produced by a chemical reaction

Activation Energy

Energy needed to get a reaction started

Catalyst

substance that speeds up the rate of a chemical reaction

Enzyme

protein catalyst that speeds up the rate of specific biological reactions

Substrate

reactant of an enzyme-catalyzed reaction