When most proteins, fats, and carbohydrates are digested completely, they are converted to end products that

• are soluble and can easily pass through cell membranes

• contain long chains of amino acids and fat acids

• contain atoms of nitrogen, carbon, hydrogen, and oxygen

• are a direct result of dehydration

Living organisms can best be distinguished from non-living things by determining the presence or absence of

• carbon atoms

• metabolic activities

• oxygen atoms

• chemical reactions

Vegetable oils, such as corn oil, belong to which general class of organic substances?

• lipids

• carbohydrates

• proteins

• salts

The invention of the compound light microscope allowed scientists to observe cells, helping them

• determine the number of atoms in a molecule

• discover cells as a basic similarity among organisms

• study the behavior of chordates

• develop techniques for growing plants in a lab

Which term refers to the maintenance of a stable internal environment in an organism?

• respiration

• metabolism

• regulation

• homeostasis

Living things are primarily composed of which elements?

• carbon, hydrogen, chlorine, and sulfur

• carbon, hydrogen, oxygen, and nitrogen

• iron, calcium, hydrogen, and oxygen

• chlorine, carbon, calcium, and sulfur

Which sequence of terms is in the correct order from simplest to most complex?

• cells > tissues > organs > organ systems

• tissues > organisms > cells > organ systems

• cells > tissues > organ systems > organs

• organs > organisms > organ systems > cells

Organisms combine simple molecules to form complex molecules by the process of

• ingestion

• synthesis

• regulation

• digestion

Organisms are composed of

• organic compounds only

• inorganic compounds only

• both organic and inorganic compounds

• neither organic nor inorganic compounds

In living organisms, lipids function mainly as

• sources of stored energy and transmitters of genetic information

• sources of stored energy and components of cellular membranes

• transmitters of genetic information and catalysts of chemical reactions

• catalysts of chemical reactions and components of cellular membranes