BIOL 1120 Austin Peay State University GEN BIOL II
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Why is metabolic cooperation necessary for nitrogen fixation?
Oxygen inhibits nitrogen fixation, so some species use
specialized cells such as heterocysts to cooperate with
photosynthetic cells by exchanging nitrogen for glucose.
What is the human microbiome?
The human microbiome is a mutualistic relationship in which
gut bacteria support immune function and mental health.
What are Microevolution and Macroevolution?
Microevolution is the process of evolution, while
macroevolution is the pattern resulting from those processes
over time.
List and define the 5 mechanisms of evolutionary change.
,1. Mutation: Random changes in DNA sequence; the source of
genetic variation. 2. Genetic Drift: Random selection of
individuals due to chance events (e.g., Founder/Bottleneck
Effects).
3. Nonrandom Mating: Mates are selected based on specific
traits (e.g., Sexual Selection).
4. Gene Flow: Movement of individuals between populations.
5. Natural Selection: Proliferation of advantageous alleles in
specific environments, leading to adaptive phenotypes.
Why is genetic variation a necessity and what are its sources?
Variation is necessary so populations have the traits needed to
adapt to environmental changes. Mutation is the primary
source, increased by crossing over, independent assortment,
and random mating.
Which mechanism produces adaptive change?
Natural Selection is the only mechanism that results in shifts
toward adaptive phenotypes.
How does natural selection work?
Selection acts on existing genetic variation. Adaptive traits
increase an individual's fitness (survival and reproduction).
Heritable traits are passed to offspring, increasing their
frequency over generations.
What is speciation and what is required for it to occur?
,Speciation is the splitting of one species into two. It requires
population isolation, genetic and phenotypic divergence, and
reproductive barriers.
What is allopatric speciation?
Speciation that occurs when populations are geographically
isolated, creating reproductive isolation.
What is the difference between gradual and punctuated
speciation?
Gradual speciation occurs slowly over time; punctuated
speciation occurs rapidly.
List the Linnaean classification levels and define binomial
nomenclature.
Levels: Domain > Kingdom > Phylum > Class > Order > Family >
Genus > Species. Binomial nomenclature uses a two-part name
(Genus species) for clarity.
What are the issues with the Linnaean classification system?
It does not always reflect evolutionary history, lacks detail on
relationships within levels, and may group organisms based on
convergent traits rather than ancestry.
Define Convergent Evolution, Analogous Traits, and
Homologous Traits.
Convergent Evolution: unrelated species evolve similar traits.
Analogous Traits: similarities due to convergence. Homologous
Traits: shared evolutionary history, even if physical form differs.
, What is Systematics and a Phylogenetic Tree?
Systematics classifies organisms based on evolutionary
relationships. A phylogenetic tree is a visual hypothesis of these
relationships.
Define Synapomorphy and Clade.
Synapomorphy: a shared derived homologous trait.
Clade: a monophyletic group including a common ancestor and
all descendants.
How do you select the most plausible phylogenetic tree?
Use Maximum Parsimony (fewest changes) or Maximum
Likelihood (highest probability based on evolutionary patterns).
Explain the roles of outgroups, polarization, and 0/1 in tree
building.,
Outgroups help determine character polarity (ancestral 0 vs
derived 1).
How did early Earth differ from today?
It had a reducing atmosphere with low oxygen; life likely arose
near volcanic or hydrothermal vents.
What are the 4 macromolecules and how did they originate?
Proteins, lipids, carbohydrates, nucleic acids; can form
abiotically under early-Earth conditions.
Why were cell membranes and RNA essential to early life?
Cumulative Final Section- NO EXAM 4 MATERIAL ON THIS
SET 2026 Questions and Answers Already Graded A+
Premium Exam Tested And Verified
Why is metabolic cooperation necessary for nitrogen fixation?
Oxygen inhibits nitrogen fixation, so some species use
specialized cells such as heterocysts to cooperate with
photosynthetic cells by exchanging nitrogen for glucose.
What is the human microbiome?
The human microbiome is a mutualistic relationship in which
gut bacteria support immune function and mental health.
What are Microevolution and Macroevolution?
Microevolution is the process of evolution, while
macroevolution is the pattern resulting from those processes
over time.
List and define the 5 mechanisms of evolutionary change.
,1. Mutation: Random changes in DNA sequence; the source of
genetic variation. 2. Genetic Drift: Random selection of
individuals due to chance events (e.g., Founder/Bottleneck
Effects).
3. Nonrandom Mating: Mates are selected based on specific
traits (e.g., Sexual Selection).
4. Gene Flow: Movement of individuals between populations.
5. Natural Selection: Proliferation of advantageous alleles in
specific environments, leading to adaptive phenotypes.
Why is genetic variation a necessity and what are its sources?
Variation is necessary so populations have the traits needed to
adapt to environmental changes. Mutation is the primary
source, increased by crossing over, independent assortment,
and random mating.
Which mechanism produces adaptive change?
Natural Selection is the only mechanism that results in shifts
toward adaptive phenotypes.
How does natural selection work?
Selection acts on existing genetic variation. Adaptive traits
increase an individual's fitness (survival and reproduction).
Heritable traits are passed to offspring, increasing their
frequency over generations.
What is speciation and what is required for it to occur?
,Speciation is the splitting of one species into two. It requires
population isolation, genetic and phenotypic divergence, and
reproductive barriers.
What is allopatric speciation?
Speciation that occurs when populations are geographically
isolated, creating reproductive isolation.
What is the difference between gradual and punctuated
speciation?
Gradual speciation occurs slowly over time; punctuated
speciation occurs rapidly.
List the Linnaean classification levels and define binomial
nomenclature.
Levels: Domain > Kingdom > Phylum > Class > Order > Family >
Genus > Species. Binomial nomenclature uses a two-part name
(Genus species) for clarity.
What are the issues with the Linnaean classification system?
It does not always reflect evolutionary history, lacks detail on
relationships within levels, and may group organisms based on
convergent traits rather than ancestry.
Define Convergent Evolution, Analogous Traits, and
Homologous Traits.
Convergent Evolution: unrelated species evolve similar traits.
Analogous Traits: similarities due to convergence. Homologous
Traits: shared evolutionary history, even if physical form differs.
, What is Systematics and a Phylogenetic Tree?
Systematics classifies organisms based on evolutionary
relationships. A phylogenetic tree is a visual hypothesis of these
relationships.
Define Synapomorphy and Clade.
Synapomorphy: a shared derived homologous trait.
Clade: a monophyletic group including a common ancestor and
all descendants.
How do you select the most plausible phylogenetic tree?
Use Maximum Parsimony (fewest changes) or Maximum
Likelihood (highest probability based on evolutionary patterns).
Explain the roles of outgroups, polarization, and 0/1 in tree
building.,
Outgroups help determine character polarity (ancestral 0 vs
derived 1).
How did early Earth differ from today?
It had a reducing atmosphere with low oxygen; life likely arose
near volcanic or hydrothermal vents.
What are the 4 macromolecules and how did they originate?
Proteins, lipids, carbohydrates, nucleic acids; can form
abiotically under early-Earth conditions.
Why were cell membranes and RNA essential to early life?
