Chapter 18 Sections :)

question

How are living things organized for study?
answer

Biologists use a classification system to name organisms with a universally accepted name. They also group organisms in a logical manner. Organisms placed into a particular group are more similar to one another than they are to organisms in other groups.
question

Describe the system for naming species that Linnaeus developed.
answer

Each species s assigned a two-part scientific name.
question

What are the seven taxonomic categories of Linnaeus’s classification system? Rank these taxa in hierarchical order, beginning with the largest level and ending with the smallest.
answer

Kingdom, phylum, class, order, family, genus, and species.
question

Why do scientists avoid using common names when discussing organisms.
answer

Because common names vary among languages and even among regions within a single country.
question

What is binomial nomenclature?
answer

a two-word naming system.
question

Look at figure 18-5 above. Are foxes more closely related to sea stars or to snakes? Explain.
answer

They are more closely related to snakes, because they are in the same phylum.
question

How is information about evolutionary, or phylogenetic, relationships useful in classification?
answer

Organisms are placed in various taxonomic groups based on evolutionary descent.
question

How are genes used to help scientists classify organisms?
answer

Scientists compare the DNA of different organisms to establish similarities between them and reconstruct possible evolutionary relationships.
question

What is the principle behind cladistic analysis?
answer

Cladistic analysis traces the process of evolution in a group of organisms by focusing on unique features that appear in some organisms but not in others.
question

What gene indicates that yeasts and humans share a common ancestor?
answer

A gene that codes for the protein myosin.
question

Describe the relationship between evolutionary time and the similarity of genes in two species.
answer

The longer it has been since two species descended from a common ancestor, the more different their genes are likely to be.
question

Would a barnacle’s DNA be more similar to the DNA of a crab or that of a limpet. Explain.
answer

It would be more similar to the DNA or crab because barnacles and crabs have a closer evolutionary relationship.
question

What are the six kingdoms of life as they are now identified?
answer

Archaebacteria, Eubacteria, Protista, Plantae, Fungi, and Animalia.
question

What are the three domains of life?
answer

Archaea, Bacteria, and Eukarya.
question

Why was the kingdom Monera divided into two separate kingdoms?
answer

Monera was divided into two kingdoms because scientists have come to recognize profound differences among two broad group of Monera.
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Why might kingdom Protista be thought of as the “odds and ends” kingdom.
answer

Members of the kingdom Protista display the greatest variety, sharing characteristics with plants, fungi, or animals; protists cannot be classified in any other group.
question

How are the members of the kingdom Fungi different from members of the kingdom Plantae? How are members of the two kingdoms similar?
answer

Fungi are heterotrophic; Plantae are autotrophic. Both are nonmotile.
question

Which kingdoms include only prokaryotes? Which kingdoms include only heterotrophs?
answer

Eubacteria and Archaebacteria include only prokaryotes. Fungi and Animalia contain only heterotrophs.

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