BIOLOGY Midterm
Homoplastic structures are a result of ____ evolution.
convergent
Which statement about an F factor is FALSE?
It is found in recipient cells, not donor cells.
Prions induce normal Prp on the surface of brain cells to misfold and cause brain damage.
True
If a population of 1000 individuals has 120 aa genotypes, 460 Aa genotypes, and 420 AA genotypes, what is the allele frequency of the dominant allele (A)?
0.65
Because whales breathe via lungs, have a little hair when born, and nurse their young, these ____ characters allow us to classify them as mammals.
shared derived
In ____ selection, individuals with a phenotype near the mean are favored over those at the phenotypic extremes.
stabilizing
What are the viruses that attack bacteria?
Phages
How do retroviruses differ from other RNA viruses?
Retroviruses have reverse transcriptase instead of RNA-dependent RNA polymerase.
The distinctive mating signals that have evolved as part of an animal's courtship illustrate what type of reproductive isolating mechanism?
behavioral isolation
The traditional class Reptilia is ____ because it does not include all descendants of the most recent common ancestor of reptiles.
paraphyletic
At what stage of a lytic infection are phage components put together to make new viruses?
assembly
The surface of a Paramecium is covered with thousands of short, hair-like ____.
cilia
The bacterium that causes botulism disease is harmless until it:
contains a certain prophage DNA.
Allopatric speciation is often exemplified in which type of geographical area or biome?
islands
Which is an example of adaptive radiation?
Four flowers of different species that evolved from a common ancestor due to selective pressures in slightly different niches
Dolphins share synapomorphies with mammals.
True
Which are evolutionary modifications that improve the survival and reproductive success of an organism?
adaptations
An example of homologous structures is the wing of a bat and the:
arm of a human.
The most common outcome in interspecific hybrid offspring is no viable gametes. This happens because of:
defective meiosis
Temporal and habitat isolation is classified as what type of reproductive barrier?
prezygotic barriers
Peptidoglycan consists of:
sugars crosslinked with proteins
Which of the following can produce a population of individuals with a relatively high frequency of a harmful or rare allele?
the founder effect
An example of homoplastic structures is the wing of a butterfly and:
wing of a bird.
What is a prophage?
It is phage DNA that is integrated into bacterial DNA.
Which characteristic defines a virus?
Viruses cannot metabolize.
At what stage of the lysogenic cycle would a prophage appear?
integration
What are the small circles of DNA that exist within the bacterial cytoplasm in addition to the bacterial chromosome?
plasmids
Which hypothesis asserts that viruses are remnants of cellular organisms and evolved from small cells that were parasites in larger cells?
regressive hypothesis
After a fire, a population of ants was reduced from 1 million to 1000. What type of genetic drift will occur in the gene pool of this population when it expands again?
a genetic bottleneck
When phenotypes are favored at one extreme of a normal distribution, ____ selection occurs.
directional
If the allele or genotype frequencies deviate from the values predicted by the Hardy-Weinberg principle, the population is:
evolving
What are the two major forces contributing to allopatric speciation?
genetic drift and natural selection
What is the only source of all new alleles in a closed (isolated) population?
mutation
In the accompanying figure, the taxon labeled II is:
paraphyletic
Gram-positive bacteria would stain ____ in a gram stain because of a thick layer of ____ in their cell walls.
purple; peptidoglycan
The five stages of a lytic infection are attachment, penetration, __________, assembly, and release.
replication
The first cells were most likely heterotrophic anaerobes because:
they utilized preformed organic molecules and did not need oxygen.
Refer to the accompanying table. What is the allele frequency of allele D? Genotype Number DD 100 Dd 700 dd 200
0.45
The allele freqs. of the M and N blood group alleles are 0.6 and 0.4. How many of a population of 500 would be expected to have MN blood type if the population is in HW equilibrium
240
A characteristic that is independently acquired by reversal or convergent evolution exhibits homology.
False
Parabasilids are excavates that lack functional mitochondria and lack a Golgi complex.
False
When a population goes through a bottleneck, genetic drift occurs in the large population of survivors of a severe change in environment.
False
Ancestors of ____ may have possessed mitochondria, which were lost or reduced during evolutionary history.
Giardia
Which classification level contains the greatest number of species?
domain
A taxon that includes all the descendants of an ancestor is called:
monophyletic
Cows and other ruminates rely on a ____ relationship with bacteria in their digestive tract.
mutualistic
The organism labeled B in the accompanying figure is a common ancestor to:
organisms 2, 3, 4, 5 and 6.
The specificity of viruses to different types of cells is due to ____ sites on the host cell.
receptor
The scientific study of the diversity of organisms and the evolutionary relationships between them is referred to as:
systematics
During the 1920s to 1940s, biologists combined Mendelian genetics with Darwin's theory to form a unified explanation of evolution that is referred to as:
the modern synthesis.
____ is a form of genetic exchange in bacteria that involves contact between two cells.
Conjugation
Which statement describes a temperate virus?
A temperate virus does not always destroy its host.
___________ is the scientific study of the diversity of organisms and their evolutionary relationships.
Systematics
Which statement about viruses is FALSE?
Viruses can manufacture proteins.
Membership in a clade cannot be established by shared ancestral traits alone.
True
What is the outcome of the process of conjugation between two Paramecium cells?
Two new genetically identical cells that differ genetically from what they were before
The most significant difference between archaea and bacteria is the:
absence of peptidoglycans in the cell walls of archaea.
Which protist group is characterized by having a micronucleus and a macronucleus?
ciliates
Phylogenetic systematics produce branching diagrams called:
cladograms
Members of the alveolates are characterized by the presence of:
flattened vesicles under the plasma membrane
Zea mays is the scientific name of the corn plant. Zea represents the:
genus
A porpoise and a dolphin, both mammals, mate and produce an embryo, but the embryo fails to complete development. This event describes:
hybrid inviability.
A taxon that diverges earlier and is sister to the other taxa being considered in cladistic analysis is a(n):
outgroup
A monophyletic group is defined by:
shared derived characters
Which statement about bacteria is FALSE?
Bacteria are not cellular and are sometimes not classified as life forms.
Why is it believed that RNA was the first informational molecule to evolve?
RNA molecules are able to function as both enzymes and substrates for their own replication.
In the accompanying figure, the pair of organisms that have the most recent ancestor is:
2 and 3.
Whose findings of evolution by natural selection were presented with those of Darwin?
Alfred Wallace
Who is responsible for the first concept regarding the passing on traits or characteristics that were acquired during the lifetime of an organism to its offspring?
Jean Baptiste de Lamarck
For the relative proportions of alleles and genotypes in successive generations to stay the same, which condition must be met for the population?
There can be no natural selection.
Four of the following ideas are consistent with Darwinian evolution. Which one is the exception?
Traits acquired during an individual's life are passed on to its offspring.
According to the serial endosymbiosis hypothesis, the ancestors of mitochondria are thought to be purple bacteria.
True
What type of organism possesses multiple sets of chromosomes from different species?
an allopolyploid
Which algal group contains individuals that are typically unicellular and form siliceous shells?
diatoms
Which reproductive isolation mechanism explains why a large dog, such as a Newfoundland, would not normally mate with a small dog, such as a Chihuahua?
mechanical isolation
Which is the only process that can lead to adaptations and directed genetic change of a population?
natural selection
A taxon that diverges earlier than the other taxa being considered in cladistic analysis is a(n):
outgroup
What is the protein coat of a virus called?
Capsid
What type of conversion occurs when a bacterium carrying viral genes takes on new, atypical characteristics?
Lysogenic
One critical requirement for life to arise on Earth was time for which to occur?
Molecules to accumulate and react with one another
After kingdom, what is the next taxon by which organisms are grouped?
Phylum
In the accompanying figure, note the variation in these closely related birds. What does this illustrate?
adaptive radiation
Which type of protist is responsible for malaria in humans, parasitic to both humans and mosquitoes?
apicomplexans
Linnaeus simplified scientific classification by developing:
binomial system of nomenclature.
Some protists consist of a single cell with multiple nuclei. This condition is known as:
coenocytic
The Hardy-Weinberg principle is applicable provided that migration:
does not occur.
Given the diversity in protist ultrastructure and molecular data, biologists regard the protists as a(n) ____ group, meaning that some are descendants of a common eukaryote ancestor.
paraphyletic
When faced with multiple possible cladograms, the criteria of ____ can be employed to pick the "best" hypothesis.
parsimony
What is a chain of round bacteria called?
streptococci
Which best describes a population that forms a new species within the same geographical region as the original species?
sympatric speciation
One group of fruit flies reproduces in August and one group reproduces in September. Which of the following mechanisms is preventing them from cross breeding?
temporal isolation
If an animal population is diploid, then each individual possesses:
term-7 two alleles for each locus.
Most protists are ____, with each cell forming a complete organism capable of performing all the functions characteristic of life.
unicellular
If a population of 2000 individuals has 120 aa genotypes, what would the genotype frequency of aa be?
0.06
In a certain population, the allele causing sickle cell anemia has an allele frequency of 0.4. If the population is in genetic equilibrium for this locus, what fraction of the population would be carriers for the allele (heterozygous individuals)?
0.48
In a certain population, the allele frequencies of the M and N blood group alleles are 0.6 and 0.4, respectively. How many of a population of 500 would be expected to have MN blood type if the population is in genetic equilibrium for the MN locus?
240
What are Koch's postulates?
A set of guidelines to demonstrate that a specific pathogen causes specific disease symptoms
The term clade most closely refers to:
a group of organisms that share common characteristics inherited from a common ancestor.
Evolution is genetic change in ____ that occurs over time.
a population
When the reproductive cells of different species are incompatible and cannot accomplish fertilization, it is referred to as:
gametic isolation.
What best describes all of the alleles for all the loci present in a population?
gene pool
Black bears and brown bears co-occur but black bears spend their time in the woods and brown bears along the river. Which of the following best describes why they don't interbreed?
habitat isolation
The evolutionary species concept states that for a population to be declared a separate species, it must:
have diverged significantly from other populations.
If individuals in the same town continue to only mate with other individuals from the same town, one would expect to see an increase in ____ within the population.
homozygosity
Suppose a gene is transferred naturally by a bacterium from a plant genome to an insect genome within the same generation. What process does this illustrate?
horizontal gene transfer
