Tortora | 9780137941612| Chapter 1-28 | All Chapters with
Answers and Rationals
living things too small to be seen with the unaided eye - ANSWER: microorganisms
Microorganisms are important in maintaining Earth's - ANSWER: ecological balance
Some microorganisms live in ______ and ______ and are needed to maintain good health. - ANSWER:
humans and animals
In a _______ system designed by Carolus Linnaeus (1735), each living organism is assigned two names
- ANSWER: nomenclature
The two names consist of a ______ and a ________ ________, both of which are underlined or
italicized. - ANSWER: genus and a specific epithet
Bacteria are ____________ organisms. Because they don't have a nucleus, they are described as
prokaryotic. - ANSWER: unicellular
Most bacteria have a _____________ cell wall; they divide using binary fission, and they may posses
flagella. - ANSWER: peptidoglycan
Bacteria can use a wide range of ________ _______ for their nutrition - ANSWER: chemical
substances
_________consist of prokaryotic cells; they lack peptidoglycan in their cell walls - ANSWER: archaea
What are the main types of archaea - ANSWER: methanogens, extreme halophiles, extreme
thermophiles
(mushrooms, mold, and yeasts) have eukaryotic cells (cells with a true nucleus). Most are multicellular
- ANSWER: fungi
Fungi obtain nutrients by - ANSWER: absorbing organic material from the environment
Protozoa are - ANSWER: unicellular eukaryotes
protozoa obtain nourishment by ___________ or _________ through specialized structures. -
ANSWER: absorption or ingestion
_____ are unicellular or multicellular eukaryotes that obtain nourishment by photosynthesis -
ANSWER: algae
Algae produce ______ and _________ that are used by other organisms. - ANSWER: oxygen and
carbohydrates
_______ are noncellular entities that are parasites of cells. - ANSWER: viruses
viruses consist of a _________ ______ _____ (DNA or RNA) surrounded by a protein coat. An
envelope may surround the coat. - ANSWER: nucleic acid core
The principal groups of multicellular animal parasites are flatworms and roundworms, collectively
called ________ - ANSWER: helminths