Biology Mid-Term

Science

Science

An organized way of gathering and analyzing evidence about the natural world

Observation

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

Inference

A logical interpretation based on what scientists already know

Hypothesis

A scientific explanation for a set of observations that can be tested in ways that support or reject it

Experiment

a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact.

Independent Variable

in an experiment, the variable that is manipulated (changed) by the person doing the experiment

Dependent Variable

in an experiment, the responding variable (the variable that changes in response to changes the person doing the experiment has made)

Control Group

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

Data

The information gathered during an experiment

Theory

A well-tested explanation that unifies a broad range of observations and hypotheses

Bias

a point of view that is personal rather than scientific

Biology

the study of life

Stimulus

A signal to which an organism responds

Cell

the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body.

DNA

a molecule containing the universal genetic code

Sexual Reproduction

The organism has two parents

Asexual Reproduction

The new organism has a single parent

Metabolism

ability to break stuff down

Heredity

passing among characteristics genetically

Homeostasis

internal physical and chemical conditions that organisms maintain

Biosphere

hydrosphere, atmosphere, surface of earth

Evolution

cumulative change in characteristics of an organism over time

Atom

smallest unit of an element

Nucleus (of an atom)

control center of an atom/ stores all information

Electron

negative charge

Neutron

neutral charge

Proton

positive charge

Element

pure substance that consists of only one type of atom

Isotope

same number of protons and a different number of neutrons

Compound

chemical combination of two or more elements in definite proportions

Ionic Bond

one or more electrons are transferred from one atom to another

Ion

atom that has a positive or negative charge

Covalent Bond

type of bond between the atom in which the electrons are shared

Molecule

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

Hydrogen Bond

The attraction of a hydrogen that has a partial positive charge on one molecule to an oxygen atom that has a partial negative charge on a neighboring molecule.

Cohesion

An attraction between molecules of the same substance allowing them to stick together

Adhesion

An attraction between molecules of different substances - allows a meniscus to form when water is in a graduated cylinder

Mixture

Material composed of two or more substances physically placed together but not chemically combined

Solution

A mixture where all of its components are uniformly/evenly distributed throughout - it has the same composition of components in all locations of the mixture

Solvent

The substance that does the dissolving in a mixture

Solute

The material that is dissolved in the mixture

Suspension

A mixture consisting of water and undissolved materials such as blood or milk

pH Scale

A measurement system used to determine how acidic or basic a solution is

Acid

A compound that produces hydrogen ions in a water solution

Base

A compound that produces hydroxide ions in a water solution

Buffer

A substance that in solution helps to prevent sharp changes in the pH

Monomer

Smaller molecular units that assemble into larger molecules

Polymer

Larger molecule made up of many smaller molecules that are joined together

Monosaccharide

Simple sugars that are building blocks of more complex carbohydrates

Carbohydrate

Molecules made of carbon hydrogen and oxygen in a 1:2:1 ratio and used to provide energy and for building structures

Lipid

Biomolecule made up mostly of carbon and hydrogen that is used to store energy and construct biological membranes

Nucleic Acid

Macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus

Nucleotide

Subunit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

Protein

Macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

Amino Acid

Compound with an amino group on one end and a carboxyl group on the other end

Peptide Bond

Formed between the amino group of one amino acid and the carboxyl group of another amino acid

Fatty Acid

the monomer that builds lipids

Glycerol

molecule that combines with fatty acids to form a lipid

Organic Compound

compounds in living things made of carbon

Chemical Reaction

Process that changes, or transforms, one set of chemicals into another set of chemicals

Reactant

Elements or compounds that enter into a chemical reaction

Product

Elements or compounds produced by a chemical reaction

Activation Energy

Energy that is needed to get a reaction started

Enzyme

Protein catalyst that speeds up the rate of specific biological reactions

Catalyst

Substance that speeds up the rate of a chemical reaction

Substrate

Reactant of an enzyme-catalyzed reaction

Active Site

The location on an enzyme where the substrates bind to the enzyme - its shape is complementary to the shape of the substrate

Ecology

The scientific study of interactions amoung organisms and between organisms and their physical environment

Species

A biological species is a group of organisms that can reproduce with one another in nature and produce fertile offspring.

Population

the whole number of people or inhabitants in a country or region

Community

a unified body of individuals

Ecosystem

a biological community of interacting organisms and their physical environment.

Biome

an area classified according to the species that live in that location

Abiotic Factor

non-living factors that impact an ecosystem

Biotic Factor

a living organism that shapes its environment

Atmosphere

the layers of gases surrounding a planet

Hydrosphere

all the waters on the earth's surface, such as lakes and seas, and sometimes including water over the earth's surface, such as clouds.

Geosphere

any of the almost spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere.

Climate

Long term patterns of temperature and precipitation over many years

Greenhouse Effect

the trapping of the sun's warmth in a planet's lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface

Weather

the state of the atmosphere at a place and time as regards heat, dryness, sunshine, wind, rain

Latitude

the angular distance of a place north or south of the earth's equator

Climate Zones

Climate zones are areas with distinct climates, which occur in east-west direction around the Earth hehehe

Ocean Currents

the continuous, predictable, directional movement of seawater driven by gravity, wind (Coriolis Effect), and water density

Canopy

the dense ceiling of leaves and tree branches formed by closely spaced forest trees

Understory

consists of trees stunted through lack of light, other small trees with low light requirements

Humus

the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms.

Taiga

a forest of the cold, subarctic region

Permafrost

A layer of permanently frozen subsoil found in the tundra

Photic Zone

The area of the water column that receives sunlight

Aphotic Zone

The area in the water column that does not receive light

Plankton

Organisms that are suspended in the water and are pushed around by the water

Wetland

an ecosystem where water either covers the soil or is present at or near the surface for at least part of the year

Estuary

A wetland formed where a river meets the sea

Autotroph

organisms that can capture energy from sunlight or chemicals and use that energy to produce food

Primary Producer

the first producers of energy rich compounds that can be used later by other organisms

Chemosynthesis

the process in which autotrophs use chemical energy to produce carbohydrates

Photosynthesis

the process in which autotrophs capture light energy and use it to convert carbon dioxide and water into oxygen and sugar

Heterotroph

organisms that rely on other organisms that they eat for their energy and food

Detritus

organisms that feed on dead/decaying matter - i.e. earthworms