Chp 18.5 Flashcards
Genus
Is a group that includes a number of very closely related species; each of these species within a genus includes populations of organisms that can potentially interbreed under natural conditions (genus Sialia (bluebirds) includes three species: the eastern bluebird and the mountain bluebird
Taxonomy
The branch of biology that is concerned with naming and classifying organisms. - Established by Swedish naturalist Carl von Linne (1707-1778), who called himself Carolus Linnaeus.
Scientific Name
its the name of an organism that designates its genus and species. binomial nomenclature. Genus name appears first, followed by the species. Genus Cap species lower case. used for overcoming language barrier.
Species
Organisms that can potentially interbreed under natural conditions.
Taxonomic Ranks (the Linnaean Classification System)
- Domain, 2. Kingdom, 3. Phylum, 4. Class, 5. Order, 6. Family , 7. Genus , 8. Species.
Phylogeny
Evolutionary history, process of classification.
Systematics
The science of reconstructing phylogeny. Evolutionary trees called clades. Seeks to reconstruct the tree of life. They also look at anatomical characteristics such as body structure and internal structure. Therefore, they must also share genetic similarities for such characteristics.
Clades
Groups of the systematics classification system that include species linked by descent from a common ancestor. Like the taxonomic ranks, can be arranged in a hierarchy with smaller clades nested within larger ones. Evolutionary trees.
DNA Sequencing
Determining the sequence of nucleotides in segments of DNA. Organisms genotypes to investigate relatedness among different types of organisms. Closely related species have similar DNA Sequences. Sometimes also in Chromosomes.
Carl Woese
Microbiologist pioneer. Showed that biologists had overlooked a key even in the early history of life, one that demanded a new and more accurate classification of life. Studied the biochemistry of prokaryotic organisms by studying nucleotide sequences of the RNA. Differentiated Bacteria and the Archaea.
Biodiversity
The total range of species diversity.
What are the Domains of life?
Bacteria, Archaea, and Eukarya. Within Eukarya: fungi, plantae and animalia are monophyletic clades.
How many species exist?
1.5 million have been named; estimates of the total number of species range up to 100 million. 7,000 to 10,000 new species identified per year.
Bacteria
constitute a large domain (or kingdom) of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most habitats on the planet, growing in soil, water, acidic hot springs, radioactive waste, and deep in the Earth’s crust, as well as in organic matter and the live bodies of plants and animals, providing outstanding examples of mutualism in the digestive tracts of humans, termites and cockroaches.
Archaea
Single cell organisms ; These microbes have no cell nucleus or any other membrane-bound organelles within their cells.
Domain
The broadest category for classifying organisms; organisms are classified into three domains: Bacteria, Archaea, and Eukarya.
Eukarya
an organism whose cells contain complex structures enclosed within membranes. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried.
Kingdom
The second broadest taxonomic category, consisting of related phyla. Related kingdoms make up a domain.
Phylum
In Linnaean classification, the taxonomic rank composed of related classes. Related phyla make up a kingdom.
Class
in Linnaean classification, the taxonomic rank composed of related orders. Closely related classes form a phylum.
Order
in Linnaean classification, the taxonomic rank composed of related families. Related orders make up a class.
Family
Taxonomic rank composed of related genera. Closely related families make up an order.
Genus
Ranks above species and below families.
What is the main reason scientists use Latin scientific names?
Latin names are recognized worldwide, overcoming language barriers.
What is the correct way to write the scientific name of the wolf?
Canis lupus.
The largest or most inclusive group?
Phylum
Flagellum or Flagella
A long, hair-like, motile extension of the plasma membrane; in eukaryotic cells, it contains microtubules arranged in a 9 +2 pattern. The movement of flagella propel some cells through fluids. Motile – they can move about.
Biofilms
A community of prokaryotes of one or more species, in which the prokaryotes secrete and are embedded in slime that adheres to a surface. Resistant to antibacterial treatment.
Bacteria and Archaea consist of
Prokatyotes
Endospores
Forms inside bacterium. Contains a genetic material and a few enzymes encased within a thick protective coat. -A protective resting structure of some rod-shaped bacteria that withstands unfavorable environmental conditions.
Prokaryote are anaerobes
Their metabolisms do not require oxygen. It allows them to inhabit oxygen-free environments and allows prokaryotes to exploit habitats that are off-limits to eukaryotes. –Organism that can live and grow without oxygen.
Mutations
Source of genetic variability, are the results of mistakes in DNA replication during cell division. In bacteria, since they reproduce at a much higher rate, this amplifies the rate at which it can mutate and allow for survival and spread quickly.
Binary Fission
Asexually reproduction; a form of cell division that is much simpler than mitotic cell division. It produces genetically identical copies of the original cell. Occurs every 20 minutes.
A rapid reproductive rate allows for rapid evolution and mutations in DNA spread.
Conjugation
Exchange genetic information without reproducing. The plasma membranes of two conjugating prokaryotes fuse temporarily to form a cytoplasmic bridge across which DNA travels. (in bacteria, a specialized extension is called a sex pili that attaches to a recipient cell, drawing it closer to allow conjugation)
Plasmid
Where much of the DNA transferred during bacterial conjugation is contained; a small circular DNA molecule that is separate from the single bacterial chromosome. Carry genes for for antibiotic resistance or alleles of genes also found on the main bacterial chromosome.
Diverse metabolisms on Prokaryotes
Autotrophs, Heterotrophs, Chemoautotrophs