Chapter 3 Vocabulary

Question 1

Ecology

Answer 1

The scientific study of relationships between organisms and their environment. It is concerned with the life histories, distribution and behavior of individual species as well as the structure and function of natural systems at the level of populations, communities, and ecosystems

Question 2

Matter

Answer 2

Anything that takes up space and has mass

Question 3

Conservation of Matter

Answer 3

In any chemical reaction, matter changes form; it is neither created nor destroyed

Question 4

Elements

Answer 4

Molecules composed of one kind of atom; cannot be broken into simpler units by chemical reactions

Question 5

Atoms

Answer 5

The smallest unit of matter that has the characteristics of an element; consists of three main types of subatomic particles: protons, neutrons, and electrons

Question 6

Atomic Number

Answer 6

The characteristic number of protons per atom of an element. Used as an identifying attribute

Question 7

Isotopes

Answer 7

Forms of a single element that differ in atomic mass due to a different number of neutrons in the nucleus

Question 8

Compounds

Answer 8

Molecules made up of two or more kinds of atoms held together by chemical bonds

Question 9

Molecule

Answer 9

A combination of two or more atoms

Question 10

Ions

Answer 10

Electrically charged atoms that have gained or lost electrons

Question 11

Acids

Answer 11

Substances that release hydrogen ions (protons) in water

Question 12

pH

Answer 12

A value that indicates the acidity or alkalinity of a solution on a scale of 0 to 14, based on the proportion of H+ ions present

Question 13

Organic Compounds

Answer 13

Complex molecules organized around skeletons of carbon atoms arranged in rings or chains; includes biomolecules, molecules synthesized by living organisms

Question 14

Deoxyribonucleic Acid (DNA)

Answer 14

A giant molecule composed of millions or billions of nucleotides (sugars and bases called purines and pyramidines held together by phosphate bonds) that form a double helix and store genetic information in all living cells

Question 15

Cells

Answer 15

Minute biological compartments within which the processes of life are carried out

Question 16

Enzymes

Answer 16

Molecules, usually proteins or nucleic acids, that act as catalysts in biochemical reactions

Question 17

Metabolism

Answer 17

All the energy and matter exchanges that occur within a living cell or organism; collectively, the life processes

Question 18

Energy

Answer 18

The capacity to do work (that is, to change the physical state or motion of and object)

Question 19

Kinetic Energy

Answer 19

Energy contained in moving objects such as a rock rolling down a hill, the wind blowing through the trees, or water flowing over a dam

Question 20

Potential Energy

Answer 20

Stored energy that is latent but available for use. A rock poised at the top of a hill or water stored behind a dam are examples of potential energy

Question 21

Chemical Energy

Answer 21

Potential energy stored in chemical bonds of molecules

Question 22

Heat

Answer 22

A form of energy transferred from one body to another because of a difference in temperatures

Question 23

First Law of Thermodynamics

Answer 23

States that energy is conserved; that is, it is neither created nor destroyed under normal conditions

Question 24

Second Law of Thermodynamics

Answer 24

States that, with each successive energy transfer or transformation in a system, less energy is available to do work

Question 25

Entropy

Answer 25

Disorder in a system

Question 26

Chemosynthesis

Answer 26

The process in which inorganic chemicals, such as hydrogen sulfide (HS) or hydrogen gas, serve as an energy source for synthesis of organic molecules

Question 27

Photosynthesis

Answer 27

The biochemical process by which green plants and some bacteria capture light energy and use it to produce chemical bonds. Carbon dioxide and water are consumed while oxygen and simple sugars are produced

Question 28

Cellular Respiration

Answer 28

The process in which a cell breaks down sugar of other organic compounds to release energy used for cellular work; may be anaerobic or aerobic, depending on the availability of oxygen

Question 29

Species

Answer 29

A population of morphologically similar organism that can reproduce sexually among themselves but that cannot produce fertile offspring when mated with other organisms

Question 30

Population

Answer 30

A group of individuals of the same species occupying a given area

Question 31

Biological Community

Answer 31

The populations of plants, animals, and microorganism living and interacting in a certain area at a given time

Question 32

Ecosystem

Answer 32

A specific biological community and its physical environment interacting in an exchange of matter and energy

Question 33

Producers

Answer 33

An organism that synthesizes food molecules from inorganic compounds by using an external energy source; most producers are photosynthetic

Question 34

Productivity

Answer 34

The synthesis of new organic material. That done by green plants using solar energy is called primary productivity

Question 35

Biomass

Answer 35

The total mass or weight of all the living organisms in a given population or area

Question 36

Food Chain

Answer 36

A linked feeding series; in an ecosystem, the sequence of organisms through which energy and materials are transferred, in the form of food, from one trophic level to another

Question 37

Food Web

Answer 37

A complex, interlocking series of individual food chains in and ecosystem

Question 38

Trophic Level

Answer 38

Step in the movement of energy through an ecosystem; an organism’s feeding status in an ecosystem

Question 39

Consumers

Answer 39

Organisms that obtains energy and nutrients by feeding on other organism or their remains

Question 40

Hebivores

Answer 40

An organism that only eats plants

Question 41

Carnivores

Answer 41

Organisms that mainly prey upon animals

Question 42

Omnivores

Answer 42

An organism that eats both plants and animals

Question 43

Scavengers

Answer 43

An organism that feeds on the dead bodies of other organisms

Question 44

Detritivores

Answer 44

Organisms that consume organic litter, debris, and dung

Question 45

Decomposers

Answer 45

Fungi and bacteria that break complex organic material into smaller molecules

Question 46

Hydrologic Cycle

Answer 46

The natural process by which water is purified and made fresh through evaporation and precipitation. This cycle provides all the freshwater available for biological life

Question 47

Carbon Cycle

Answer 47

The circulation and reutilization of carbon atoms, especially via the the processes of photosynthesis and respiration

Question 48

Carbon Sinks

Answer 48

Places of carbon accumulation, such as in large forests (organic compounds) or ocean sediments (calcium carbonate); carbon is thus removed from the carbon cycle for moderately long to very long periods of time

Question 49

Nitrogen Cycle

Answer 49

The circulation and reutilization of nitrogen in both inorganic and organic phases

Question 50

Phosphorus Cycle

Answer 50

The movement of phosphorus atoms from rocks through the biosphere and hydrosphere and back to rocks

Question 51

Sulfur Cycle

Answer 51

The chemical and physical reactions by which sulfur moves into or out of storage and through the environment