Classification and Taxonomy---Chapter 18 Flashcards
Taxonomy
- scientists use a classification system to name and group organisms in a logical manner.
- assign each organism with a universally accepted name
Binomial nomenclature
- developed by Carolus Linnaeus during 18th century
- two words naming system –> binomial nomenclature
- two part scientific name in italics
- first word capitalized, second word lower case
- E.g. Canis lupus
Genus
- first part scientific name
- the genus to which organism belongs
- a group closely related species
Linnaeus’s system of classification has how many levels?
7
what are Linnaeus’s system of classifications levels?
kingdom, phylum, class, order, family , genus and species
what is kingdom?
the largest and most inclusive
what is phylum?
several different classes share important features and characteristics
what is class?
composed of similar order
what is order?
a broad category composed of similar families
what is family?
genera that share many characteristics
what is species?
unique to each species within the genus
Linnaeus’s system of classifications order?
KPC OFGS (king Phillip came over for good soup)
phylogeny?
is the evolutionary relationship between organisms.
Classification using Cladograms?
identifies new characteristics that evolve over time.
derived characteristics?
is the emergence of a new trait found in the recent lineage but not a more distant member.
a cladogram?
a diagram that shows the evolutionary relationship between organisms.
dichotomous keys?
a sequence of steps allowing the identification of a living thing to use a series of paired statements that describe physical characteristics different organisms.
similarities in DNA and RNA?
genes show important similarities at the molecular level of many different organisms. It shows evolutionary relationships and can be used for classification.
similar genes?
genes of diverse organisms show many similarities. indicates common ancestry.
DNA evidence?
can show evolutionary relationships of species and how species have changed. more similar DNA sequences of two species –> the more recently they shared a common ancestor.
molecular clock?
the average rate at which a species genome accumulates mutations, used to measure their evolutionary divergence and in other calculations.
why do biologists assign each organism a universally accepted name?
scientific names are used to avoid a confusion that may arise when discussing the organism in question.
what criteria are used to classify an organism?
scientist use similarities and evolutionary traits to classify an organism.
what features of binomial nomenclature make it useful for scientists of all nation?
the use of Latin makes it useful for scientist of all nations.
sequence Linnaeus’s seven taxonomic categories from smallest to largest.
kingdom, phylum, class, order, family, genus, species.
explain the goal of evolutionary classification.
the goal of evolutionary classification is to look for a common ancestor.
how is a cladogram used I classification?
cladograms use derived characters to classify.
how do biologists use DNA and RNA to help classify organisms?
similarities in DNA & RNA are compared to determine the relationships between species. the more similarities the more closely related species are to one another.
describe how a molecular clock is used to estimate the length of time two related species have been evolving independently.
a clock uses the appearance of DNA mutations at at constant rate to measure the length of time that had elapsed between the evolution of two related species.
how do domains and kingdoms differ?
domains are more inclusive with fewer similarities being shared between members. kingdoms have fewer members that share more similarities.
what characteristics are used to place an organism in the domain bacteria?
what characteristics are used to place an organism in the domain bacteria are linear DNA no nucleus, and no membrane bound organelles.
which domain consists of prokaryotes whose cell walls lack peptidoglycan?
archaebacteria lack peptidoglycan.
describe the four kingdoms that comprise the domain Eukarya?
Animalia, plantae, fungi and protista.
what characteristic(s) differentiate the kingdom Animalia from the kingdom plantae?
plants have cell walls, chloroplasts, and large vacuole which animal cells do not have.
prokaryotic?
has no nucleus
