Evolutionary Biology Exam 1 Review

When Darwin first proposed evolution

Some geologists believed that the earth was 
unchangeable (uniformitarianism)

Geologists had already observed that vast stretches 
of time were required to produce some rock formations.

Catastrophism was already accepted among geologists 
to explain that the earth was older than commonly believed.

No theory could explain that the earth was old enough 
for natural selection to work.

Geologists had already observed that vast stretches of time were required to produce some rock formations

The unit(s) upon which evolution consists of happens to be:

Changes in genotypes

Changes of heritability

Changes in allele frequencies

Changes in phenotypes

Changes in allele frequencies

During years 1-6 of infection, HIV evolution is extremely fast, 
 but it slows down during year 7. What would be the underlying 
cause for the HIV virus evolution to slow?

CD4 T cell count decrease

Increase in the change of novel epitopes

Viral load decrease

Replication of the HIV virus decreased

CD4 T cell count decrease

HIV initiates replication by latching on to which two proteins?

CD4 and CCR5 (a coreceptor)

CD4 and CCR32 (a coreceptor)

delta32 and CCR5

TCR and CD4

CD4 and CCR5 (a coreceptor)

The fungus Phytopthera infestans caused the Irish potato famine 
because it infected potato crops and made them rot. 
Phytopthera infestans is only virulent when it can avoid the 
potato plant's defenses. 
A loss-of-function mutation in the Avirulence gene allows this to 
happen and causes potato disease, but only when fungal strains are 
homozygous recessive (aa), not when they are AA or Aa. You observe a 
potato crop where 75/150 plants have rotted from Phytopthera infestans. 
At the Avirulence locus, what is the frequency of the a allele?

50%

Not enough information

100%

75%

Not enough information

During the Chronic phase of HIV infection, the patient usually experiences few symptoms.

False

True

True

Historically, snakes had legs and now they are 
vestigial structures in certain species.

false

True

True

What is it called when two species experience similar environments 
and evolve the same adaptations?

Coevolution

Co-adaptation

Convergence

Coincidence

Convergence

The amount of sunlight any orchid receives per day influences 
growth rate, flowering time, and number of flowers. 
This is an example of:

phenotypic influence

phenotypic plasticity

phenotypic cognition

phenotypic diversity

Phenotypic plasticity

Isotopes with shorter half-lives are more useful for 
dating the age of Earth.

false

true

False

The age of processed pseudogenes can be estimated by the 
number of mutations they have accumulated.  We expect to find that:

The older the pseudogene, the less valuable 
it is for determining relationships

Older pseudogenes are shared by few species

Newer pseudogenes are shared by many species

Older pseudogenes are shared by more species

Older pseudogenes are shared by more species

The delta-32 allele has the lowest frequencies in areas where

HIV infection is rampant or abundant

HIV strains are missing the viral protein Nef

HIV contains the CD4 receptor within its RNA genome

HIV infection is rare

HIV infection is rampant or abundant

How does AZT work?

Interrupts the pathway that adds more nucleotides

AZT is not a drug.

Is a HAART cocktail.

Helps reverse transcriptase add more thymidine to the proteins

Interrupts the pathway that adds more nucleotides

What is a synapomorphy?

a unique trait found in a species.

a trait that is shared with the out group

a common trait found with no shared ancestry.

a homologous trait that is shared among certain species.

A homologous trait that is shared among certain species

What is a paraphyletic group of organisms?

Groups that include all descendants of a common ancestor

Groups that include paranormal species and their ancestors.

Group that includes a common ancestor 
and some but not all descendants.

Groups that include all but one descendent of a common ancestor.

Groups that include a common ancestor and some but not all descendants

A reaction norm is:

the average time it takes to answer this or any 
other question

the phenotypic possibilities of a single genotype 
across an environmental range

The opposite of phenotypic plasticity

The genotypic expression range in a single environment

The phenotypic possibilities of a single genotype across an environmental range

Mutation rates can be influenced by:

the species

all of the above

the gene region

the environment

All of the above

In Sub-Saharan Africa, the primary mode of transmitting HIV is:

male-male sex

male-female sex

transfusions with contaminated blood

Consuming bush meat

Male-female sex

In the chronic phase of HIV infection, 
CD4 T-cell counts decrease continually.

False

True

True

Viral load in a patient that is HIV positive

Continues to decrease until the patient develops AIDS.

Initially increases, then decreases, 
and then increases until the patient develops AIDS.

Initially decreases, 
then increases until the patient develops AIDS.

Continues to increase until the patient develops AIDS.

Initially increases, then decreases, and then increases until the patient develops AIDS

Evolution cannot anticipate the future and produces changes in 
populations based on past environments, not future environments.

False

True

True

DNA and protein studies reveal that:

variation among individuals and populations is ubiquitous

variation is lower than what was previously thought

variation is widespread among populations but not species

Variation is widespread among species but not populations

Variation among individuals and populations is ubiquitous

A cladogram is a tree based on:

clustering only synapomorphies

clustering only genetic similarities

clustering all traits with non-negligible branch lengths

clustering only morphological traits

Clustering only synapomorphies

Which of the following may explain why HIV-1 is highly lethal?

Because HIV viral loads increase over time

Because evolution is short sighted

All choices are correct

Because HIV infects host immune cells

Because the high mutation rate of RNA viruses allows natural selection to act rapidly, enabling HIV to evolve resistance to host defenses

All choices are correct

Which of the following does not provide evidence for evolution?

the immutability of species

discovery of Archaeopteryx

Theory of Plate Tectonics

the human hemoglobin family

The immutability of species

Bayesian phylogenetic analysis differs from Maximum Likelihood 
methods in that:

they are based on the principle of parsimony

they infer the likelihood of the data given a tree

they use a bootstrapping process to determine 
confidence in the results

they infer the likelihood of a tree given the data

They infer the likelihood of a tree given the data

In a phylogeny, when evolutionary histories are not well resolved 
and the node has multiple (more than two) branches arising from it, 
this is known as:

autapomorphies

polytomy

triploidy

monophyletic groups

Polytomy

Which of the following can cause AZT to 
become less effective as a treatment for HIV infection?

AZT molecules eventually mutate into regular thymidine

Virions inside a person can mutate to a form 
that allows reverse transcriptase to use AZT as 
an efficient DNA building block

All choices are correct 

Virions inside a person can mutate to a form 
that does not allow reverse transcriptase to 
incorporate AZT into DNA strands

Virions inside a person can mutate to a form that does not allow reverse transcriptase to incorporate AZT into DNA strands

HIV was introduced into humans only once (from SIV).

false

true

False

How does a biologist assess confidence in a particular node 
of a phylogentic tree?

Bayesian Markov Chain Monte Carlo

Maximum likelihood

Bootstrapping or posterior probabilities

Polytomy

Bootstrapping or posterior probabilities

Because finches with large beaks gave birth to chicks
 with bigger beaks: 

Beak size does not influence survival 

Conspecific nest parasitism probably doesn't occur 

This example gives evidence for the inheritance of 
acquired characteristics. 

Beak size is a heritable trait 

Beak size is a heritable trait

Evolution is progressive in that complexity is always increasing 
with time.

False

True

False

The Modern Synthesis is grounded in which of the following 
disciplines synthesized with the theory of evolution: 

Mathematics 

Geology 

Genetics 

Thermodynamics 

Genetics

Which type of HIV virus is causing the AIDS epidemic?

HIV-2 subtype B

HIV-2 subtype A

SIVstm: stump-tailed macaque

HIV-1

HIV-1

If a phylogenetic tree depicts extant taxa on the right 
and the point of most recent common ancestry on the left:

The amount of time since the most recent common 
ancestor depends on the vertical spacing between taxa

An accurate phylogeny only shows taxa on the top 
and the most recent common ancestor on the bottom.

The horizontal axis represents time

The vertical axis represents time

The horizontal axis represents time

Polyploidy in animals is rare because:

they are not as promiscuous as plants or fungi

They frequently have temperature-dependent 
sex determination

diploid gametes most often combine with haploids, 
producing an unstable triploid

Recombination between parents ensures diploidy in 
offspring

Diploid gametes most often combine with haploids, producing an unstable triploid

Which is NOT a category of drugs in use to disrupt 
which stage of HIV's life cycle?

Fusion inhibitors

Cholesterol inhibitors

coreceptor inhibitors

Integrase inhibitors

Cholesterol inhibitors

Shared similarity of genetic flaws (e.g. mutations)

Provides further evidence of common descent

Helps identify disease

does not occur

Cannot yet be explained by evolutionary biologists,
 but will likely be explained some day.

Provides further evidence of common descent

HIV follows which flow of genetic information?

RNA to DNA to mRNA to protein

DNA to RNA to mRNA to protein

protein to DNA to mRNA

RNA to mRNA to DNA to proteins

RNA to DNA to mRNA to protein

During a drought in the Galapagos, small, 
easily eaten seeds become less abundant leaving only large, 
hard-cased seeds only birds with large beaks can eat.  
If this drought persists for several years, 
then what would be expected from natural selection?

More birds with small beaks dying than large-beaked 
birds giving way to offspring produced in subsequent 
generations having a higher percentage of 
large-beaked birds.

Birds with small beaks mutating their beak genes with 
the result that later-generation offspring have larger beaks.

Small birds growing larger beaks by exercising their
mouth parts.

Birds with larger beaks eating less to save some for 
birds with smaller beaks.

More birds with small beaks dying than large-beaked birds giving way to offspring produced in subsequent generations having a higher percentage of large-beaked birds