In the refrigeration cycle, heat is exchanged through the expansion and condensation of gases.
a. true
b. false

Give the biological term for: structures that display characteristics of living organisms only within living cells

The earth consists of a variety of different organisms. despite their diversity, however, some similarities on the structural and metabolic levels may be seen. these similarities can be attributed to a. similarities among organisms in their proteins and nucleic acids. b. the ability of organisms to readily adapt to sudden environmental changes. c. similarities in organisms' habitats and niches. d. the ability of all organisms to interbreed and produce new species.

Which of the following is not a defining characteristic of plants?