Bio 1013 exam ch. 13-15
If you examine a population for a particular gene where B represents the dominant allele and b represents the recessive allele, you find that the allele frequencies for this gene are p = 0.3 and q = 0.7. If this population is not evolving, what would be the frequency of the heterozygous genotype?
0.42
Why is the evolution of antibiotic resistance in bacteria happening so quickly?
1. Any use of antibiotics will select for resistant bacteria 2. Overuse of antibiotics in livestock 3. Overuse of antibiotics in humans 4. Bacteria can reproduce so quickly
Evidence that the Earth was much older than originally thought reached Darwin in numerous ways. Which of the following helped influence Darwin to believe in an ancient Earth?
1. Darwin found a layer of compressed seashells 30 feet above sea level while visiting the west coast of Africa 2. Darwin witnessed an earthquake that caused the coastline of Chile to rise up several feet 3. Darwin read the work of Charles Lyell, who argued that the earth was ancient and has been shaped by slow, incremental changes over vast expanses of time 4. While exploring the coast of Argentina, Darwin unearthed fossils of several large animals embedded in a sea cliff, including a giant armadillo and a giant sloth
Which of these is NOT a pattern of natural selection?
1. Diversifying selection 2. Directional selection 3. Stabilizing selection
Which of these is NOT an example of adaptive evolution?
1. Gene flow 2. Bottleneck 3. Founder effect 4. Mutation
Which process has been shown to contribute to the evolution of antibiotic resistance in S. Aureus?
1. Gene swapping with other bacterial strains 2. Overuse of antiviral medications 3. Genetic Mutations during asexual reproduction
All of Darwin's finches came from a single species with a "normal" beak. Which factor can explain the development of the variety of beaks seen in these finches today"
1. Genetic drift resulted in different islands having different allele frequencies for the genes controlling beak shape 2. Different mutations in beak shape occurred in different populations of finches 3. Different food sources on each island created selection pressure for different beak shapes on each island
Which factor may prevent most people from developing more than minor skin blemishes when they have a staph infection?
1. Helpful bacteria on their skin keep staph in check 2. They are practicing good hygiene, including frequent hand washing 3. Their immune systems are preventing the infection from spreading 4. Their skin is a physical barrier that keeps out the bacteria
Which factor is not going to affect how natural selection acts on a given group of organisms?
1. Survival rate of individuals 2. Which phenotypes are present 3. Reproductive success of individuals
Which of these does NOT influence allele frequencies in a population?
1. The Bottleneck effect 2. Genetic drift 3. Natural selection 4. Mutation
Darwin coined the term "evolution," but he preferred "descent with modification." The idea of descent with modification was solidified for Darwin when he read the political work of Thomas Malthus, who wrote a pessimistic book on population growth. Malthus' book promoted the idea that _____. Select the TWO answers that apply.
1. The human population would eventually reach its size limit due to limited resources on Earth 2. The humans would have to compete for limited resources, and only some would survive
In a population of 75 mice, what would be the size of their gene pool for a particular gene?
150
In a population of 100 mice, if the recessive allele frequency is 0.25, how many copies of the recessive alleles are found in the population?
50
Which feature did Tiktaalik possess that were not possessed by earlier vertebrates?
A flexible wrist
Which change in the evolutionary history of horses is documented by the fossil record?
A gradual decrease in the number of toes
Which scenario would be LEAST likely to result in a fossil?
A jellyfish that dies and slowly floats to the ocean floor
An organism's fitness depends on its _________.
Ability to survive and reproduce
The development and spread of a new gene for antibiotic-resistance in a population of bacteria that are exposed to that antibiotic would mean that trait is a(n) ___________.
Adaptation
The proportion of alleles present in a gene pool is called the ______ and is an important tool in measuring evolutionary changes.
Allele frequency
The collection of _______ in a population constitutes that population's gene pool.
Alleles
Antibiotic-resistant strains of bacteria tend to first be found in hospitals. Which factor explains why this is the case?
Antibiotics are more likely to be present in hospitals, thus selecting for resistant strains
Which statement regarding drug-resistant bacteria is false?
Bacteria that are sensitive to antibiotics have a reproductive advantage in all environments
Why aren't human populations evolving to produce immune systems that are able to fight off MRSA and other "superbugs"?
Because the rate of human evolution is much slower than bacterial evolution
An individual who carries staph but isn't sick is referred to as _______________.
Colonized
Despite numerous hardships, Russel Wallace was not deterred, and he almost beat Darwin to publication of his work on evolution. Why does Darwin get most of the credit for the theory of evolution?
Darwin detailed a more complete account of evolution by natural selection in his paper
Fossils are generally going to be more useful for studying animals that lived in or near water because _________
Dead animals that fall into water are more likely to be in conditions that allow fossilization
The variation in shape and function of the forelimb in tetrapods is a result of __________
Different environments leading to the evolution of different types of limbs
Darwin observed finches on the Galapagos and compared them to finches back home in England. Species of finch are distinguishable by the different size and shape of their beaks. This suggested to Darwin that _____.
Finch beaks have changed over time to match the food source that they depend on
Which statement regarding the dating of fossils is false?
Fossils can be dated using a microscope to examine tissue
Organism XYZ has a DNA sequence of GGTATAGAGT. By examining the sequence of nucleotides below, determine which organism is most closely related to organism XYZ.
GGTATAGAGG
The forelimb of a chicken and a primate contain many of the same bones arranged in the same order. This is an example of ________
Homology
What can we learn about vertebrate evolution from Tiktaalik that we did not know before?
How vertebrates evolved tetrapod limbs
The offspring produced between the mating of a tiger and a lion, a liger, which is unable to produce, is an example of which form of reproductive isolation?
Hybrid infertility
Inbreeding can lead to a decrease in genetic diversity and _______
Inbreeding depression
Darwin's finches came from a mainland species where some individuals were able to move to the islands and then spread from one island to another. Is the genetic diversity of the new population of finches on the Galápagos increased or decreased in relation to the population on the mainland, and what is this an example of?
It decreased their genetic diversity because this represents an example of genetic drift
The Tiktaalik fossil, which dates back 375 million years, is considered a transitional fossil because _________
It displays features found on both aquatic and land-dwelling species
A bacterial cell that is resistant to a particular antibiotic may spend a large amount of energy producing the modified proteins that are needed for resistance. In such a case, what would be the effect on this cell's fitness if no antibiotic was present?
Its fitness would be lower than other strains that lack resistance because it is spending energy that the resistant strains can use for other purposes, such as reproduction
Which sequence places Tiktaalik in the correct evolutionary order?
Lobed-finned fish, Tiktaalik, tetrapods
Some portions of DNA function as a kind of evolutionary clock when comparing two different species because ________
Mutations accumulate at a known rate
What is the evolutionary process called that causes antibiotic-resistant bacteria to increase and antibiotic-sensitive bacteria to decrease in an environment where antibiotics are present?
Natural selection
Which statement about evolution by natural selection is false?
Natural selection is a random change in allele frequencies over generations
Which of these is NOT used by scientists to understand evolution?
Religion
Although all organisms share the same four nucleotides, it is the ________ of these nucleotides that makes each species unique
Sequence
A transitional fossil should _______
Share some similarity with species that lived before it and some similarity with species that lived after it
Which statement expressed the only way to prevent the evolution of new antibiotic-resistant bacteria?
Stop using antibiotics entirely
A bacterial cell with which modification might be resistant to antibiotics such as methicillin?
The ability to produce an enzyme that breaks down the antibiotic
In strains of bacteria that are not resistant to beta-lactams, which part of the bacterial cells are disrupted by the antibiotic?
The cell walls
When Darwin compared the giant armadillo and sloth fossils to the living animals in Argentina, he found that _____.
The giant sloth and armadillo fossils bore a striking resemblance to the much smaller sloths and armadillos indigenous to the area
Which statement is NOT a reason why homologous structures may look very different when comparing two different species?
The homologous structures may have arisen independently in the two species that are closely related
Natural selection is the idea that _____.
The natural environment selects for favorable traits and those favorable traits are passed on to the next generation of offspring
You examine a population and note that its allele frequencies for a particular gene are p = 0.55 and q = 0.45. If you came back and examined the population after several generations and found that the values for p and q had not changed, which statement would be false for this gene?
The population is evolving
Which scenario would represent a situation that reduces the effect of genetic drift?
The population is very large
Which changes in a bacterial cell might reduce the effectiveness of beta-lactam antibiotics?
The presence of enzymes that are able to break down the antibiotic
If you examine a natural population of bacteria, it is common to find some antibiotic-sensitive and some antibiotic-resistant strains, even if the population has never been exposed to any antibiotic. Which explanation could account for this situation?
The resistant strain developed as a mutation and had no negative effect on fitness
Shubin and Daeschler specifically traveled to Ellesmere island to hunt for fossils because _______
The rocks on the island were of the right age to contain transitional vertebrate fossils
If you examine the gene pool of a population that is evolving due to genetic drift, what do you predict will occur with the allele frequencies?
There is no way to tell how p or q will change
In addition to the beak differences, which statement indicates that the different finch populations found throughout the Galapagos Islands have experienced speciation?
They can no longer interbreed
Inheritance of acquired characteristics, called Lamarkianism, is based on the idea that _____.
Traits that an organism acquires over the course of its lifetime can be passed on to offspring
All of these statements are true regarding S. Aureus EXCEPT:
nearly 1% of the US population is colonized with S. Aureus