Ch18 classification

family

(biology) a taxonomic group containing one or more genera

class

(biology) a taxonomic group containing one or more orders

order

(biology) taxonomic group containing one or more families

phylum

(biology) the major taxonomic group of animals and plants

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

A gene that codes for the protein myosin.

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

All animals can be traced back to older ancestors and they might have similar genes in different species because at one time the species were more closely related to each other.

Why do scientists avoid using common names when discussing organisms?

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

How are living things organized for study?

Biologist use a classification system to name organisms with a universally accepted name. They group organisms in a logical manner.

What is the principle behind cladistic analysis?

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.

binomial nomenclature

Classification system in which each species is assigned a two-part scientific name

cladogram

Diagram that shows the evolutionary relationships among a group of organisms

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

Eubacteri, Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia

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

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

kingdom

First and largest category used to classify organisms

Are foxes more closely related to sea stars or to snakes? Explain.

Foxes are more related to snakes because hey are in the Kingdom and Phylum category.

genus

Group of closely related species, and the first part of the scientific name in binomial nomenclature

taxon

Group or level of organization into which organisms are classified

Why was the kingdom Monera divided into two seperate kingdoms?

It was composed of two distinct groups.

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

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

Protista

Kingdom composed of eukaryotes that are not classified as plants, animals, or fungi

fungi

Kingdom composed of heterotrophs; many obtain energy and nutrients from dead organic matter

archaebacteria

Kingdom of bacteria that live in extreme environments

animalia

Kingdom of multicellular eukaryotic heterotrophs whose cells do not have cell walls

plantae

Kingdom of multicellular photosynthetic autotrophs that have cell walls containing cellulose.

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.

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

Describe the system for naming species that linnaeus developed.

Linnaeeus's hierarchical system of classification includes seven levels. They are from smallest to largest species, genus, family, order, class, phylum, and kingdom.

Why might kingdom Protista be thought of as the odds and ends kingdom?

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

evolutionary classification

Method of grouping organisms together according to their evolutionary history.

molecular clock

Model that uses DNA comparisons to estimate the length of time that two species have been evolving independently

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

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

How are genes used to help scientists classify organisms?

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

archaea

Single-celled, no nucleus, Live in harsh condisions, oldest organisms on earth

What is binomial nomenclature?

The systems for naming organisms in which each organism is given a unique, two part scientific name

How are menbers of the kingdom fungi different from members of the kingdom Plantae? How are members of the two kingdoms similar?

They are both multicellular. Fungi also has unicellular organisms and is heterotrophs. Plantae are autotrophs and have cell walls that contain cellulose.

What are three domains of life?

bacteria, eukarya; arhcaea

derived characters

characteristics that appear in recent parts of a lineage but not in its older members

eukarya

consists of all organisms that have a nucleus

taxonomy

discipline of classifying organisms and assigning each organism a universally accepted name

eubacteria

kingdom of unicellular prokaryotes whose cell walls are made up of peptidoglycan

domain

most inclusive taxonomic category; larger than a kingdom

bacteria

single-celled organisms that lack a nucleus; prokaryotes

phylogeny

the study of evolutionary relationships among organisms