BIO 1108 EXAM QUESTIONS AND
ANSWERS A+ GRADED
phylogeny
the evolutionary history of a group of organisms
what makes up a phylogenetic tree?
a branch: represents a population over time; a node( or fork ): represents the point in
time when an ancestral species split into two or more descendantspecies; a tip(or
terminal node) represents a group that is living today or ended in extinction.
phenetic approach
method for constructing a phylogenetic tree by computing statistics that summarizes
overall similarity between populations
cladistic approach
based on the realization that relationships among species by identifying shared derived
characters
synapomorphies
a trait found in certain groups orf organisms that exist in no others. A homologous trait
derived from a common ancestor.
Homology ("same source")
when traits are similar due to shared ancestry
Homoplasy
When traits are siilar for reasons other than common ancestry.
Convergent evolution
when natural selection favors similar solutions to the problems posed by a similar way
of making a living.
parsimony
the most likely explanation or pattern is the one that implies the least amount of change.
Eukarya
Domain of all organisms whose cells have nuclei, including protists, plants, fungi, and
animals
Protists
all eukaryotes that are not green plants, fungi, or animals. there are no synapomophies
in this group of eukaryotes
paraphyletic group
represents some but not all of the descendants of a single common ancestry.
Monophyly
all descendants plus most recent common ancestor
Paraphyly
taxon includes the mrca and some , but not all, of its descendants
Polyphyly
formed when two lineages convergently evolve similar character states. Do not contain
a common ancestor.
Ribosomes
Conduct protein synthesis in cells
, Rough ER
Network of branching sacs that function as protein synthesis and processing centers.
Golgi apparatus
stack of flattened cisternae that function as protein processing center
smooth ER
Network of branching sacs that function in lipid synthesis
Lysosomes
function in digestion and recycling
Peroxisomes
Functions in oxidation of fatty acids, ethanol, or other compounds
Vacuoles
Large, primarily water filled sacs for waste disposal and promotion of plant stature.
Mitochondria
Functions in ATP synthesis
Chloroplast
Produces ATP and Sugars via photosynthesis
Cytoskeleton
Provides structural support to the cell and allows for the movement of materials
Plasma Membrane
Uses selective permeability to maintain intracellular environment
Cell Wall
an extracellular structure that distinguishes plant cells from animal cells. it gives each
cell suport as plants dont have an internal or external skeleton.
Describe the composition and function of a cell wall.
made of cellulose fibers embedded in other polysaccharides and proteins. they are
chemically active. they protect teh plant cell and maintain itsshape and prevents
excessive uptake of water.
Primary Wall
Principally a loose matrix of randomly arranged cellulose fibrils. it is in the youngest
cells and is relatively flexible.
Middle Lamella
It is a thin layer between primary walls of adjacent cells. it is the glue that holds together
adjacent cells. It is made up of Petic substances.
plasmodesmata
Cytoplasmic channels connecting adjacent plant cells and allowing for the movement of
molecules and ions between cells
Parenchyma cells
• Most abundant cell
• Remain alive when mature
• Only have primary cell wall (thin and flexible)
• Perform most metabolic functions of plant (photosynthesis, aerobic respiration, and
food storage)
• Unspecialized
• Can divide and differentiate into other types of plant cells
collenchyma cells
ANSWERS A+ GRADED
phylogeny
the evolutionary history of a group of organisms
what makes up a phylogenetic tree?
a branch: represents a population over time; a node( or fork ): represents the point in
time when an ancestral species split into two or more descendantspecies; a tip(or
terminal node) represents a group that is living today or ended in extinction.
phenetic approach
method for constructing a phylogenetic tree by computing statistics that summarizes
overall similarity between populations
cladistic approach
based on the realization that relationships among species by identifying shared derived
characters
synapomorphies
a trait found in certain groups orf organisms that exist in no others. A homologous trait
derived from a common ancestor.
Homology ("same source")
when traits are similar due to shared ancestry
Homoplasy
When traits are siilar for reasons other than common ancestry.
Convergent evolution
when natural selection favors similar solutions to the problems posed by a similar way
of making a living.
parsimony
the most likely explanation or pattern is the one that implies the least amount of change.
Eukarya
Domain of all organisms whose cells have nuclei, including protists, plants, fungi, and
animals
Protists
all eukaryotes that are not green plants, fungi, or animals. there are no synapomophies
in this group of eukaryotes
paraphyletic group
represents some but not all of the descendants of a single common ancestry.
Monophyly
all descendants plus most recent common ancestor
Paraphyly
taxon includes the mrca and some , but not all, of its descendants
Polyphyly
formed when two lineages convergently evolve similar character states. Do not contain
a common ancestor.
Ribosomes
Conduct protein synthesis in cells
, Rough ER
Network of branching sacs that function as protein synthesis and processing centers.
Golgi apparatus
stack of flattened cisternae that function as protein processing center
smooth ER
Network of branching sacs that function in lipid synthesis
Lysosomes
function in digestion and recycling
Peroxisomes
Functions in oxidation of fatty acids, ethanol, or other compounds
Vacuoles
Large, primarily water filled sacs for waste disposal and promotion of plant stature.
Mitochondria
Functions in ATP synthesis
Chloroplast
Produces ATP and Sugars via photosynthesis
Cytoskeleton
Provides structural support to the cell and allows for the movement of materials
Plasma Membrane
Uses selective permeability to maintain intracellular environment
Cell Wall
an extracellular structure that distinguishes plant cells from animal cells. it gives each
cell suport as plants dont have an internal or external skeleton.
Describe the composition and function of a cell wall.
made of cellulose fibers embedded in other polysaccharides and proteins. they are
chemically active. they protect teh plant cell and maintain itsshape and prevents
excessive uptake of water.
Primary Wall
Principally a loose matrix of randomly arranged cellulose fibrils. it is in the youngest
cells and is relatively flexible.
Middle Lamella
It is a thin layer between primary walls of adjacent cells. it is the glue that holds together
adjacent cells. It is made up of Petic substances.
plasmodesmata
Cytoplasmic channels connecting adjacent plant cells and allowing for the movement of
molecules and ions between cells
Parenchyma cells
• Most abundant cell
• Remain alive when mature
• Only have primary cell wall (thin and flexible)
• Perform most metabolic functions of plant (photosynthesis, aerobic respiration, and
food storage)
• Unspecialized
• Can divide and differentiate into other types of plant cells
collenchyma cells
