question

There are millions of different _______ on Earth.

answer

species

question

To study this great diversity of organisms, biolgists must give each organism a ________.

answer

name

question

Biolgists also must ______ living things into groups in a ______ way.

answer

organize, logical

question

Therefore, biolgists need a _______ system.

answer

classification

question

_________ is the discipline of naming and classifying organisms.

answer

Taxonomy

question

To be useful, the names that are assigned should be _______ accepted.

answer

universally

question

A good classification system should also grou together organisms that are more _______ to each other than they are to organisms in other groups.

answer

similar

question

Common names for organisms vary by ________ and ______. This creates confusion.

answer

language, region

question

By the 1700s, scientists had tried to solve this problem by agreeing to use a _________ for each species.

answer

single name

question

At first, the names they used were very ______.

answer

long

question

Then, ____________ devoloped a two-word naming system called ____________.

answer

carolus linnaeus, binomial nomenclature

question

This ______ is still used today.

answer

system

question

In bionomial nomenclature, each species is assigned a ________ scientific name.

answer

two-part

question

The first partof the name refers to ________ (plural:genera).

answer

genus

question

A ______ is a group of closely related species.

answer

genus

question

For example, the genus ______ contains six bear species.

answer

ursus

question

The second part of the name, along with the genus name, refers to a single _______ (plural: species).

answer

species

question

Recall that species consist of individuals who can ___________.

answer

interbreed

question

The name __________, for example, refers to the species polar bear.

answer

ursus maritimus

question

Linnaeus's system of classification has ______ different levels.

answer

seven

question

From smallest to largest, the levels are species, _____, _______, ______, ______, ________, and ___________.

answer

genus, family, order, class, phylum, kingdom

question

Each of the levels is called a ____ (plural:taxa).

answer

taxon

question

Just as a genus is a group of similar species, a _______ is a group of similar genera, an ______ a group of similar families, a ______ a group of similar orders, a ________ (plural:phyla) a group of similiar classes, and a ________ a group of similar phyla.

answer

family, order, class, phylum, kingdom

question

Linnaeus named two kingdoms of living things, the _______ (animal) and _______ (plant).

answer

animalia, plantae

question

Linnaeus and other taxonomists have always tried to group organisms according to _________ important characteristics.

answer

biologically

question

However, they have not always agreed upon which characteristics are most _________.

answer

important

question

Early classifications were based on ___________.

answer

visible similarities

question

Biologists now grou organisms according to _______________.

answer

evolutionary relationships

question

The study of evolutionary relationships among organisms is called ____________.

answer

phylogeny

question

Classification based on evolutionary relationships is called __________________.

answer

evolutionary classification

question

Species within one genus are more closely __________ to each other than to species in another genus.

answer

This is because all members of a genus share a recent common ________.

answer

ancestor

question

All _______ in a family also share a common ancestor

answer

genera

question

However, this common ancestor is farther in the ______ than the common ancestor of species within a genus.

answer

past

question

The higher the level of the _____, the father back in time is the common ancestor of all the organisms in that taxon.

answer

taxon

question

Many biologists now use a method called ________________ to determine evolutionary relationships.

answer

cladistic analysis

question

Cladistic analysis is based on _______________.

answer

derived characters

question

Derived characters are new _______ that arise as a group evolves over time.

answer

traits

question

Derived traits are therefore found in closely related _______ but not in their distant ancestors.

answer

organisms

question

Derived characters can be used to construct a ___________.

answer

cladogram

question

A cladogram is a ________ that shows the evolutionary relationships among a group of organisms.

answer

diagram

question

A cladogram is basically an ______________, much like a family tree.

answer

evolutionary tree

question

All organisms have ______ and ______.

answer

DNA, RNA

question

Because DNA and RNA are so ________ across all forms of life, these molecules ca be compared to different species.

answer

similar

question

The more similar the molecules are in different species; the more recently the species shared a ______________.

answer

common ancestor

question

Therefore, the more closely __________ they are.

answer

Comparisons of DNA can also be used to estimate the _______ that two species have been evolving independently.

answer

length

question

A model called a __________ can be used for this purpose.

answer

molecular clock

question

The model asumes that ________________, which do not afect phenotype, acccumulate in gene pools.

answer

neutral mutations

question

_____________ evolving independently from each other will accumulate different neutral mutations through time.

answer

Two species

question

The more there are of these different neutral mutations, the _______ the two species have been evolving independently.

answer

longer

question

As biologists learned more aboutthe natural world, they realized that Linnaeus's two kingdoms, _______ and ________, did not represent all life forms.

answer

animalia, plantae

question

First, microorganisms, such as ________, were discovered.

answer

bacteria

question

Microorganisms did not seem to fit into either kingdom, so they were placed in their own kingdom, called _______.

answer

protista

question

Then, mushrooms, yeast, and molds were separated from plants and placed in their own kingdom, called _______.

answer

fungi

question

Later, bacteria were separated from other Protista and placed in another new kingdom, called _______.

answer

monera

question

Finally, the Monera were divided into two kingdoms: __________ and ____________.

answer

eubacteria, archaebacteria

question

It includes the kingdoms ___________, __________, ________, __________, ___________, and __________.

answer

eubacteria, archaebacteria, protista, fungi, plantae, animalia

question

By the 1990s, a ______________ system of classification was proposed.

answer

six-kingdom

question

A new taxon, called the ________, is now used by many biologists.

answer

domain

question

The domain is _____ level higher than the kingdom.

answer

one

question

Three domains are recognized: __________, _________, and _________.

answer

bacteria, archaea, eukarya

question

The domain Bacteria includes _________ organisms without a __________. They have cell walls containing a substance called __________.

answer

unicellular, nucleus, peptidoglycan

question

These organisms have cell walls that do not contain __________.

answer

peptidoglycan

question

The domain Archaea corresponds to the kingdom ___________.

answer

archaebacteria

question

THe domian Eukarya includes the four remaining kingdoms: _________, __________, __________, and ______________.

answer

protista, fungi, plantae, animalia

question

All members of the domain __________ have cells with a nucleus.

answer

Eukarya

question

Most members of the kingdom __________ are unicellular organisms.

answer

Protista

question

Some Protista are __________; others _________.

answer

autotrophs, heterotrophs

question

Most members of the kingdom Fungi are __________, and all are ___________. All members of the Kingdom Plantae are multicellular ____________.

answer

multicellular, heterotrophs, autotrophs

question

The domain Bacteria corresponds to the Kingdom _________.

answer

Eubacteria

question

The domain _________ also includes unicellular organisms witohout a nucleus.

answer

Archaea

question

All members of the kingdom Plantae are ___________ autotrophs.

answer

multicellular

question

Most plants cannot __________ and their cells have _________.

answer

move about, cell walls

question

All members of teh kingdom _______ are multicellular heterotrophs.

answer

animalia

question

Most animals can move about, and their cells lack ____________.

answer

cell walls

Chapter 18: Classification – Flashcards

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