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Chapter 18 review

Describing and naming each species

First step in understanding and studying diversity

Many animals have multiple names;
different animals may share a common name;
some names are too long and descriptive

Problems with naming different species

Different scientists focused on different characteristics

It was hard to standardize descriptive scientific names because...

Dichotomous keys

Used to identify organisms;
consists of a series of paired statements or questions that describe alternative possible characteristics of an organism

Carolus Linneaus

developed a two-word naming system called binomial nomenclature


In binomial nomenclature, each species is assigned to a ___ ____ scientific name


Scientific names written in ______

Capital letter,
Lowercase letter

In binomial nomenclature, first word begins with _______ ______, second word begins with _________ ______

Ursus maritimus

Scientific name of a polar bear


First part of scientific name according to binomial nomenclature;
a group of a similar species


Genus which contains five species of bears

Unique to each species

Second part of scientific name according to binomial nomenclature is ... (not a term)


group of individuals capable of interbreeding and producing fertile offspring

Species name

Often a description of an important trait or the organism's habitat


Refers to the sea;
polar bears often live on pack ice that floats in the sea


In a useful classification system, organisms in a particular group are more _______ to one another than they to organisms in other groups


The science of naming and grouping organisms;
goal is to organize living things into groups that have biological meaning


The groups produced by systematics


Linnaeus also developed a classification system that formed a _________ or set of ordered ranks;
his original system had four levels

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

Over time, Linnaeus's original classification system expanded to include seven hierarchical taxa: ...

Species and genus

Two smallest categories in Linnaeus's classification system

Camelus bactrianus

Scientific name of a camel with two humps;
second part was named came from an ancient country in Asia


Genus which includes two different species of camels

Camelus dromedarius

Scientific name of a camel with one hump


In deciding how to place organisms into larger taxa, Linnaeus grouped species according to __________ similarities and differences


The South American _____ bears some resemblance to Bactrian camels and dromedaries


Llamas are placed in this genus;
they are not part of the Camelus genus because, although they resemble camels, they are more similar to other South American species than they are to European and Asian camels


Several genera that share many similarities (like Lama and Camelus) are grouped into a larger category, the ______

Lama glama

Species name for llamas


Family name for Lama and Camelus


Closely related families are grouped into the next highest rank


Similar orders are grouped into the next largest rank


Order of hoofed animals with an even number of toes


Class which includes all animals that are warm-blooded, have body hair, and produce milk for their young


Classes are grouped into the next largest rank which includes organisms that are different but share important characteristics


The class Mammaliais placed in this Phylum along with other classes because all of the organisms share important body-plan features, among them a nerve chord along the back


The largest and most inclusive of Linnaeus's taxonomic categories


All multicellular organisms are placed in this kingdom


Members of a _______ determine which organisms belong to that _______ by deciding with whom they mate and produce fertile offspring


Linnaeus was a good scientist who chose his characteristics _________

Classification schemes

Many of Linnaeus's groups are still valid under modern ______________ _______

Similarities and differences

Linnaeus grouped organisms according to

In ways that reflect how closely members of those groups are related to each other.

How do modern scientists try to assign species to large groups?

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