Chapter 17 Classification of Life Flashcards
Explain the goals of systematics. List the progressively broader categories of classification used in systematics in order, from most specific to most general.
Systematics: a discipline of biology that focuses on classifying organisms and determining their evolutionary relationship
Order Species Genus Family Order Class Phylum Kingdom Doman
Describe the goals of phylogenetic systematics. Define the terms clade, monophyletic groups, shared derived characters, phylogenetic trees, and parsimony.
A phylogenetic tree is a hypothesis of evolutionary relationships within a group
cladistics uses shared derived characters to group organisms into clades, including an ancestral species and all its descendants
An inclusive clade is monophyletic
In general, parsimony is the principle that the simplest explanation that can explain the data is to be preferred. In the analysis of phylogeny, parsimony means that a hypothesis of relationships that requires the smallest number of character changes is most likely to be correct.
Compare the characteristics of the three domains of life.
Archaea-prokaryotes, different cell membranes, RNA polymerase much more like Eukarya
Bacteria-prokaryotes
Eukarya-eukaryotes (includes all of life that we think of as life and more)-includes kingdoms protista, fungi, plantae, and animalia
Compare the different shapes of prokaryotes.
Bacilli=rod
Cocci=sphere
Spirilla=spiral, (short and rigid)
Describe the structures and functions of the diverse features of prokaryotes.
-Bacterial cell walls can be distinguished with a gram stain
gram positive=simple walls with thick layer of peptidogglycan
Gram-negative=complex walls with less peptidoglycan AND outer membrane of lipids bounded to carbohydrates
Lipids of gram negative bacteria are often toxic: membrane protects them against host’s defenses and prevents the entry of antibodies: generally more threatening than gram-positive species
Prokaryotic DNA forms a circular chromosome
Plasmids=smaller rings of DNA within chrmosome
Carry genes that may provide resistance to antibodies or metabolize rare nutrients, among other metabolic activities
Many prokaryotes can transfer genes, such as antibiotic resistance genes, within or between species
Describe the basic types of protists. Explain why biologists currently think that they represent many clades.
Protists constitute several kingdoms within the domain Eukarya
Can be
Unicellular or multicellular
Microscopic or very large
Heterotrophic or Autotrophic
So what do they have in common?
All are eukaryotic
Live in moist environments
Categorized by their method of nutrition
Protists
Protoza=animal like
Heterotrophic; unicellular
categorized by how they move
EX: Amoeba, paramecium, giardiasis, plasmodium
Algae=plant like
Autotrophic; uni and multicellular; no roots, stems, or leaves
EZ: green algae, brown algae, red algae, euglenoids, Diatoms, Dinoflagellates
Fungus like
Heterotrophic; decomposers=get energy by breaking down organic matter; do not contain chitin
EX: slime molds, water molds, downy mildew
Describe the key plant adaptations to life on land.
Eukaryotic, multicellular, autotrophic Have cell walls with cellulose vascular or nonvascular Seed plants or seedless Sexual and asexual reproduction
Compare the bryophytes, seedless vascular plants, gymnosperms, and angiosperms.
bryophytes
moss, liverwort, hornwort
seedless vascular plants
fern, club moss
gymnosperms
blue spruce
angiosperms
barley grass, jarcanda
Describe the parts of a flower and explain their functions.
Anther Pollen Style Filament Stamen Stigma Pistil Ovary Ovule Sepal Petal
List the angiosperm adaptations that promote seed dispersal.
The fruits that angiosperms grew aided seed dispersal because the animal would the fruit. Then the animal would later poop out the seeds, all fertilized, and in a different area. Some seeds of certain plants were light enough that the wind could blow them into different areas. The flowers on angiosperms can be brightly colored and smell sweet. these characteristics attract pollinators that will disperse the pollen/seed of the plant.
Explain how flowers are adapted to attract pollinators.
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Describe the main traits of fungi and their ecological role.
Eukaryotic, heterotrophic, multicellular (+unicellular yeast)
Saprophytes=feed on dead or decomposing organisms
Examples include mushrooms, molds, yeasts
Chitin in cell wall distinguishes from plants and protists
Mycelium, a mass of branching, thread like filaments called hypha
Myco-fungus; mycology-study of fungi
Describe the defining characteristics of animals.
Animals are classified by possession of the following
Multicellular organization
specialization of cells: complex organ systems-nervous muscular, digestive, etc.
Cell junctions: communication between cells
Heterotrophy
contrast with autotrophy
Sexual reproduction and development
primarily sexual reproduction; however, some species alternate between sexual and asexual
Differentiation=develop from a unicellular zygote to a complex adult
Movement
sessile (stationary) vs. motile (moving) stages of life
Examine the diversity of animal phyla: Porifera, Cnidaria, Platyhelminthes, Nematoda, Mollusca, Annelida, Arthropoda, Echinodermata, and Chordata. Note several examples of each phylum.
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How do prokaryotes obtain nourishment
Prokaryotes obtain nourishment in a variety of ways
light+CO2=photoautotrophs
Light+Organic compounds=photoheterotrophs
CO2+Chemical=Chemoautotrophs
Organic compounds+chemical=chemoheterotrophs
