Bio Chapter 18 Review

The science that specializes in the classification of organisms is

taxonomy.

Solely from its name you know that Rhizopus nigricans must be

in the genus Rhizopus.

A useful classification system does NOT

use different scientific names for the same organism.

In classifying organisms orders are grouped together into

classes.

The largest and most inclusive of Linnaeus's taxonomic categories is the

kingdom.

Which of the following shows the evolutionary relationships among a group of organisms?

cladogram

A unique trait that is used to construct a cladogram is called a

derived character.

The three domains are

Bacteria, Archaea, and Eukarya.

A kingdom that includes only heterotrophs is

Fungi.

Which organism belongs in the kingdom Animalia?

octopus

Why do biologists assign each organism universally accepted name?

To provide consistency and avoid confusion.

What criteria are used to classify an organism?

Evolutionary relationships and structural similarities of organisms.

What features of binomial nomenclature make it useful for scientists of all nations?

Binomial nomenclature is useful to all scientists because each name is unique, a combination of the genus name and a term that is different for each species in the genus. Each scientific name is assigned to only one species, so different species are not confused.

Sequence Linnaeus's seven taxonomic categories from smallest to largest.

Species, genus, family, order, class, phylum, and kingdom.

Explain the goal of evolutionary classification.

To group organisms based on their evolutionary history instead of on physical similarities.

What is a derived character? Give an example of a derived character.

A derived character is a characteristic that appears in recent parts of a lineage but not in its older members; An example is a molted exoskeleton in crustaceans.

How is a cladogram used in classification?

A cladogram shows the evolutionary relationships among a group of organisms

How do biologists use DNA and RNA to help classify organisms?

Biologists choose segments of DNA and RNA that are similar and compare the sequences within those molecules. The more similar the DNA or RNA between species, the more closely related the species are assumed to be. Such comparisons can provide information that supports inferences on visible structural characteristics.

What is phylogeny?

The study of evolutionary relationships among organisms.

Describe how a molecular clock is used to estimate the length of time that two related species have been evolving independently.

A molecular clock relies on a repeating process, a mutation, to estimate the length of time that two species have been evolving. A comparison of DNA sequences indicates how alike or dissimilar the genes are. A dissimilarity of DNA sequences indicates how long ago the species shared a common ancestor.

How do domains and kingdoms differ?

A domain is more inclusive and larger than a kingdom.

What characteristics are used to place an organism in the domain Bacteria?

Members of domain Bacteria are all unicellular and prokaryotic. Cell walls contain peptidoglycan.

Which domain consists of prokaryotes whose cell walls lack peptidoglycan?

They are placed in the kingdom Archaea.

Describe the four kingdoms that comprise the domain Eukarya.

Protists, Fungi, Plantae, and Animalia.

What characteristic(s) differentiate the kingdom Animalia from the kingdom Plantae?

Members of the Animalia kingdom are heterotrophic, do not have cell walls, and are motile.