Taxonomy & The Diversity Of Life Flashcards
The branch of biology that studies the evolutionary history of organisms.
Phylogeny
The field of biology that names and organisms species based on their similarities.
Taxonomy
A field that incorporates taxonomy, variation among populations, and relationships among organisms over time to provide insight into the evolutionary history of life.
Biological Systematics
Studied the differences and similarities in the biological structure of organisms to group species using a nested hierarchical system of classification.
Carl Linnaeus
8 hierarchical groupings (taxa) used to classify species:
(largest to smallest)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Largest of 8 hierarchical groupings used to name and organize species.
Domain
The branch of biology that studies the form of organisms and relationships between their structures.
Morphology
Name species using a combination of the genus and species of the organism.
Binomial Nomenclature
The 2nd word in the scientific name generated by binomial nomenclature.
ex. Homo sapiens (sapiens)
Species Epithet
A reproductive community of populations (reproductively isolated from others) that occupies a specific niche in nature.
Species
A species is a single lineage of ancestor-decent populations that maintains its identity from other such lineages and that has its own evolutionary tendencies. —> Therefore, a species is a specific lineage evolving separately from others.
Evolutionary Species Concept
Considers 2 genetically similar populations as different species when they are geographically isolated from one another and each population carries unique morphological differences.
Phylogenetic Species Concept
The evolutionary relationship among organisms. —> Sheds light on the divergence of species through history.
Depicted using a phylogenetic tree with branches to represent lineages and nodes to depict common ancestors.
Uses synapomorphies to group similar species into clades.
Phylogeny
Derived from a common ancestor.
(ex. the tail of a monkey and the tail of a cat)
Homologous Characters
Are analogues that evolve independently (usually through convergent evolution because of similar selective pressures) so they don’t represent a shared ancestors between 2 species.
(ex. the wings of a bird and the wings of a bat)
Homoplastic Characters
Related species are ground into a branch if they share a derived character (which is a trait that differs from the ancestral state).
Clade
A trait that differs from the ancestral state.
Derived Character
Shared, derived characters.
Synapomorphies
Used to depict the evolutionary relationships among different species/groups.
Cladogram
A single species/group that’s related to all the others in the tree but is still distinct.
Outgroup
Conceptually and visually similar to a cladogram but the lengths of its branches correspond to time. —> Incorporates numerical data to detail the changes that occurred in a lineage over time.
Phylogram
(Phylogenetic Tree)
Shows the relationship between different groups of animals along with their derived characters.
Cladogram
Includes all the members of a group as well as their most recent common ancestor.
A clade is a _______ ______.
Monophyletic Taxon
Contains a common ancestor but leaves out some of its descendants.
Paraphyletic Taxon
Doesn’t include the common ancestor to all of its members.
Polyphyletic Taxon
The use of DNA and proteins in the identification and classification of species.
Molecular Systematics
Molecular Systematics
A method of identifying species based on the sequence of a standard section of DNA.
DNA Barcoding
The study of form and structure of organisms or parts of organisms.
Morphology
Species that appear identical to each other but are different at a genetic level and are unable to breed with each other.
(ex. African elephants that live in forests and African elephants that live in the Savana)
Cryptic Species
5 Kingdoms:
Animalia
Plantae
Fungi
Protista
Monera
3 Domains:
Bacteria
Archaea
Eukarya
Vast group of prokaryotic organisms that play critical roles in cycling carbon, nitrogen, and sulfur and have an important symbiotic relationship with other organisms.
Bacteria
Eubacteria (“true bacteria”)
Produce their own food from their surroundings using either light energy (in photosynthesis) or chemical energy (in chemosynthesis).
Autotrophs
Can’t produce their own food, so they ingest other organisms for their nutrition.
Heterotrophs
Rod-shaped bacteria.
Bacillus
Ball-shaped bacteria.
Coccus
Spiral-shaped bacteria.
Spirillum
Have a thick, complex outer cell wall (mostly made of peptidoglycan) that stains a characteristic purple color after Gram staining.
Gram-Positive Bacteria
Have a thinner layer of peptidoglycan in their cell wall and stain pink in gram staining.
Gram-Negative Bacteria
Diverse group of prokaryotic microorganisms. Lack membrane-bound organelles and a nuclear envelope (like bacteria). Cell walls don’t contain peptidoglycan. Well known for living in extreme/inhospitable environments.
Archaea
Make their own food from solar or chemical energy.
Autotrophic
Consuming other organisms for food.
Heterotrophic
Acquiring dissolved nutrients from decaying organisms.
Saprotropic
Change between autotrophic and heterotrophic methods of acquiring nutrients depending on what’s available.
Mixotrophic
Eukaryotes.
Divided into 4 kingdoms: animals, plants, fungi, and protists.
Eukarya
Eukarya
Mostly unicellular and relatively less complex than most other eukaryotes.
Paraphyletic so invalid taxon… Catch-all for organisms that are eukaryotes but are not animals, plants, or fungi.
Live in marine, freshwater, or other wet environments.
Have a huge impact on the earth’s ecosystem: serving as the base of several food chains decomposing dead organic material, symbiotically supporting other organisms, and creating a significant portion of the earth’s oxygen.
“Protista”
Protists roughly divided into 3 groups based on their mode of locomotion:
-Ciliates
-Flagellates
-Amoebas
Protist locomotion
Move by waving large numbers of small, hair-like cilia to propel themselves through water.
Ciliates
Protist locomotion
Move by rotating 1+ long flagella.
Flagellates
Protist locomotion
Move using pseudopods (fingerlike projections of cytoplasm).
Amoebas
(ameboid protists)
Eukarya
Plants.
Multicellular and photosynthetic.
Autotrophs (carry out photosynthesis using chloroplasts).
Critical to human life on earth. —> Humans depend on the oxygen generated and the carbon-containing compounds produced by plants carrying out photosynthesis.
Plantae
Eukarya
Include both unicellular and multicellular organisms.
Can reproduce sexually or asexually.
Non-vascular, non-moving, heterotrophic.
Essential in the breakdown/decomposition of dead matter.
Some cause diseases, others produce antibiotics.
Fungi
Eukarya
Animals.
Multi-cellular heterotrophs.
Cells organized into tissues.
Most reproduce sexually.
High degree of diversity in form and ecosystems they inhabit.
Characterized by their mode of embryonic development.
Animalia
Can use inorganic substances to produce organic compounds. —> Either through photosynthesis or chemosynthesis.
Don’t need to eat food.
Autotrophic
Need to ingest food to produce energy.
Heterotrophic
Can switch between autotrophic and heterotrophic metabolisms depending on whether nutrients are available.
Mixotrophic
Feed on decaying organic matter.
Saprotrophic
