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Midterm

BIOL150 Study Guide - Midterm Guide: Phylogenetic Tree, Binomial Nomenclature, Unicellular Organism


Department
Biology
Course Code
BIOL150
Professor
Jonathan Witt
Study Guide
Midterm

Page:
of 13
BIOL 250 Midterm 1 Review
CHAPTER 1: BIOLOGY AND THE TREE OF LIFE
Evolution: (1) The theory that all organisms on Earth are related by common ancestry and that they
have changed over time, predominantly via natural selection. (2) Any change in the genetic
characteristics of a population over time, epically, a change in allele frequencies.
Natural Selection: The process by which individuals with certain heritable traits tend to produce more
surviving offspring than do individuals without those traits, often leading to a change in the genetic
makeup of the population. A major mechanism of evolution.
Heritable: Referring to traits that can be transmitted from one generation to the next.
Population: A group of individuals of the same species living in the same geographic area at the same
time.
Natural selection acts on individuals, but evolutionary change affects only populations
Evolution Occurs when heritable variation leads to differential success in reproduction
Fitness: The relative ability of an individual to produce viable offspring compared with other individuals
in the same population.
Individuals with high fitness produce many offspring
Adaption: A trait that increases the fitness of an individual with that trait, compared with individuals
without that trait, in a particular environment.
Speciation: The evolution of two or more distinct species from a single ancestral species.
Tree of Life: A diagram depicting the genealogical relationships of all living organisms on Earth, with a
single ancestral species at the base.
Taxonomy: The branch of biology concerned with the classification and naming of organisms.
Genus: In Linnaeus’ system, a taxonomic category of closely related species. Always italicized and
capitalized to indicate that it is a recognized scientific genus.
Species: A distinct, identifiable group of populations that is thought to be evolutionarily independent of
other populations and whose members can interbreed. Generally distinct from other species in
appearance, behavior, habitat, ecology, genetic characteristics, etc.
Binomial Nomenclature:
Taxonomic Levels (Specific to Broad)
SpeciesGenusFamilyOrderClassPhylumKingdom
Taxon: Any names group of organisms at any level of a classification system.
Eukaryotes: A member of the domain Eukarya; an organism whose cells contain a nucleus, numerous
membrane-bound organelles, and an extensive cytoskeleton. May be unicellular or multicellular.
Prokaryotes: A member of the domain Bacteria or Achaea; a unicellular organism lacking a nucleus and
containing relatively few organelles or cytoskeletal components.
Phylogeny: The evolutionary history of a group of organisms.
If the theory of evolution is correct, then rRNA should be very similar in closely related organisms but
less similar in organisms that are less closely related. Groups that are closely related, like the plans,
should share certain changes in rRNA that no other species have.
Phylogenetic Tree: A diagram that depicts the evolutionary history of a group of species and the
relationships among them.
As the family tree show relationships among individuals, a phylogenetic tree shows relationships
among species. Branches that are close to one another on the phylogenetic tree are closely related
while branches that are further apart are distantly related.
Domain: (1) A section of a protein that has a distinctive tertiary structure and function. (2) A taxonomic
category, based on similarities in basic cellular biochemistry, above the kingdom level. The three
recognized domains are Bacteria, Achaea, and Eukarya.
Null Hypothesis: A hypothesis that specifies what the results of an experiment will be if the main
hypothesis being tested is wrong. Often states that there will be no difference between experimental
groups.
CHAPTER 24: Evolution by Natural Selection
Evolution: (1) The theory that all organisms on Earth are related by common ancestry and that they
have changed over time, predominantly via natural selection. (2) Any change in the genetic
characteristics of a population over time, epically, a change in allele frequencies.
Population: A group of individuals of the same species living in the same geographic area at the same
time.
Decent With Modification: The phrase used by Darwin to describe his hypothesis of evolution by atural
selection.
Fossil: Any trace of an organism that existed in the past. Includes tracks, burrows, fossilized bones, casts,
etc.
Fossil Record: All of the fossils that have been found anywhere on Earth and that have been formally
described in the scientific literature.
Sedimentary Rocks: A type of rock formed by gradual accumulation of sediment, as in riverbeds and on
the ocean floor. Most fossils are found in sedimentary rock.
Geological Time Scale: The sequence of eons, epochs, and periods used to describe the geological
history of Earth.
Transitional Form: A fossil species or population with traits that are intermediate between older and
younger species.
Vestigial Trait: Any rudimentary structure of unknown or minimal function that is homologous to
functioning structures in other species. Vestigial traits are thought to reflect evolutionary history.