Chapter 1 Flashcards
The scientific study of life
biology
What are the five fundamental characteristics of life?
- Energy
- Cells
- Information
- Replication
- Evolution
What is a theory?
an explanation for a general class of observations that are supported by a wide body of evidence
Two theories that for the framework for modern biological science:
- The Cell Theory
- The theory of evolution by natural selection
Who were the first to observe cells?
Robert Hooke and Anton van Leewenhoek
What is a cell?
a highly organized compartment bounded by a plasma membrane that contains concentrated chemicals in an aqueous solution
What does the cell theory state?
Organisms are made of cells and come from pre-existing cells
What are the implications of cell theory ?
- single and multicellular organisms come from pre-existing cells
- Descendants by ancestry
What two claims did Darwin and Wallace make regarding the natural world?
- All species are related by common ancestry
- Descent with modification
Define decent with modification
characteristics of species can be modified from generation to generation
Define Evolution
a change in the characteristics of a population over time
Define Natural selection
the mechanism which describes how evolution occurs
Natural selection occurs in populations of ___________
organisms
An organism is more competitive when it is able to do what?
reproduce and pass their traits to their offspring
What does natural selection enable?
variation in population
Define population
a group of individuals of the same species living in the same area at the same time
What are the guidelines for natural selection to occur?
- Individuals must vary in characteristics that are heritable (Must exhibit variation)
- Individuals in a population have a competitive edge over others (survival & reproduction)
Why do some traits become more common in a population over time?
those traits lead to increased success in producing offspring
Natural selection acts on _____________
individuals
Evolutionary change occurs in ________
populations
When can the variation of a population occur?
- Natural selection
- Artificial selection
How does the variation of population occur through natural selection?
Traits beneficial to the current environment are “selected” for a competitive advantage
How does the variation of population occur through artificial selection
desirable traits are identified and selected by humans to produce a population of individuals desired by humans
Define FItness
the ability of an individual to produce offspring
In biology, the term ‘fitness’ is also referred to as
Darwinian Fitness
What results in the emergence of a new species?
when adaptation results in a reproductive barrier
define speciation
a divergence process in which natural selection has caused populations of one species to diverge to form new species
Examples of how speciation occurs:
- Geographic isolation
- Climate barriers
- Mutations in proteins making sperm incompatitble with an egg
- Temperature change
Define Phylogeny
used to show the evolution of genetically related organisms
This occurs when individuals lack the ability to produce
speciation
Phylogeny is also referred to as:
The Tree of Life
This man studied rRNA
Carl Woese
What did Carl Woese study?
ribosomal RNA (rRNA)
This molecule is used to understand evolutionary relationships
rRNA
rRNA is found in (some/all) organisms
all
What makes up ribosomal RNA?
ribosomes and rRNA
What ribonucleotides is rRNA composed of?
A, U, C, and G
This molecule is used to understand the Tree of Life:
rRNA
What does the theory of evolution state?
The sequence of ribonucleotides in rRNA can change in populations over time
rRNA sequences should be (very/less) similar in closely related organisms
very
rRNA sequences should be (very/less) similar in less closely related organisms
less
The Tree of Life is also referred to as
The Phylogenic Tree of Life
A phylogenic tree is used to show the ___________ between _________
relationship; species
What do the branches that share a recent common ancestor represent in a phylogenetic tree?
The species are closely related
What do the branches that do not share a recent common ancestor represent in a phylogenetic tree?
The species are more distantly related
The tree of life indicates three major groups of organisms:
- The Eukaryotes
- Two groups of Prokaryotes
- Domain Bacteria
- Domain Archaea
Organism(s) that has a predominant nucleus
Eukarya
Organism(s) that lacks a nucleus
Domain bacteria & Domain archaea
Organism(s) that lack a nucleus and are single-celled
Domain bacteria
Organism(s) that lack a nucleus and are single-celled in extreme environments
Domain archaea
Identify the type of cell shown

Eukaryotic Cell
Identify the type of cell shown

Prokaryotic cell
The three domains of living organisms are:
Bacteria, Archea, and Eukarya
What organism is represented by the green branch and what size its rRNA (in svedberg)?

Bacteria; 16S
What organism is represented by the blue branch and what size its rRNA (in svedberg)?

Archaea; 16S
What organism is represented by the red branch and what size its rRNA (in svedberg)?

Eukarya; 18S
What molecule is used to classify organisms as Bacteria, Archaea, or Eukarya?
ribosomal RNA (rRNA)
What is a Svedberg?
a unit for sedimentation, rate, or density
Define Taxonomy
The science of naming and classifying organisms
What was Carlos Linnaeus known for?
establishing the classification system know as Taxonomy.
How is Taxonomy organized?
organisms are categorized into numerous groups from least specific (Domain) to most specific (Species)
The order of Taxonomy is as follows:
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
- Genus
- Family
- Order
- Class
- Phylum
- Kingdom
In the taxonomic system, each organism is given a unique two-part scientific name that consists of:
The genus and the species
In taxonomy, what is the genus made up of?
a closely related group of species
In taxonomy, what is a species made up of?
individuals that regularly breed together
OR
individuals whose characteristics are distinct from those of other species
An organism’s genus and species designation is called its ________ _______ or _______ ______
scientific name or latin name
What are the Rules of Nomenclature?
- Scientific names are always italicized
- Genus names are always capitalized
- Species names are not capitalized
Example: Homo sapien