Key Concepts Quiz
This activity contains 20 questions.
How are adaptations beneficial to organisms?
Adaptations help organisms survive and reproduce in
environment, such that organisms can easily move into different environments.
Adaptations help organisms survive and reproduce in a particular environment.
Adaptations allow organisms to tolerate dramatic changes in their environment (such as when a lake dries up).
Adaptations are developed by individual organisms through the use of certain body parts to accomplish particular tasks.
Why was Darwin's acceptance of an ancient, continuously changing Earth so important in his development of his ideas about evolution?
He had to accept that Earth could change in order to also accept that organisms can change.
Darwin hypothesized that as Earth changed due to volcanic eruptions, new species would appear from deep within the Earth.
Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats.
Darwin hypothesized that as Earth changed, a divine force replaced the existing species with new species that were perfectly suited to the new environment.
In artificial selection, humans provide the selective pressure for species to change and shape the evolution of various breeds. What provides the selective pressure in natural selection?
scientifically trained humans
the degree of natural genetic variation in a population
Sometimes critics charge that evolution is based on mere speculation because it cannot be directly observed or experimentally induced. Is this true of evolution by natural selection?
Yes, it is technically true. However, the effects of natural selection are very obvious and it is hard to come up with a better explanation for adaptations.
Yes. Natural selection makes sense, but it works too slowly to produce observable changes in organisms.
The statement is partly true when applied to natural selection. Natural selection
be observed in bacteria and insects, but not in other organisms.
No. Natural selection changes the traits of some organisms quite quickly, in ways that are clearly adaptive. Scientists have documented such changes in thousands of studies.
Which statement reflects a possible weakness of the fossil record?
Only large animals can be fossilized.
The fossil record does not indicate chronology (the sequence of events).
Many species probably did not die in the right place at the right time to be captured in fossils, and many fossils will never by found by paleontologists.
The fossil record cannot answer any questions about behavior.
Which of the following is true of homologous structures?
They are used for the same function in different species.
They no longer have a function in the modern organism that possesses them.
They are structurally similar due to inheritance from a common ancestor.
They are structures that are ideal for the function they serve in the organism.
Which option best describes the concept of an evolutionary tree diagram?
It is a diagram that organizes species into groups based on their overall similarities and joins them into a tree of life.
It is a diagram that shows how individuals are related to one another within a species. For humans, an example would be a family tree.
Evolutionary trees relate species to each other by ancestry. An ancestor common to all of the species is placed at the root of the tree. Branch points are defined by homologous features that are shared by the descendant species along a particular branch.
Evolutionary trees relate species to each other by adaptation. Species that are adapted to similar environments share branches on the tree of life. At the root is a common ancestor that could live in most environments known to occur on Earth.
Of the scenarios below, which represents the occurrence of evolution at its smallest scale?
An individual organism begins as a single cell and develops into an adult, changing dramatically through a series of life stages.
An adult human moves from near sea level to a city high in the Andes Mountains. Her physiology changes to improve her performance in the thin atmosphere.
Over many thousands of years, the beak shape of a bird species changes to exploit a new food source.
A pesticide spray is heavily used on a particular farm. Initially it kills 98% of the grasshoppers on contact. Over several generations, the local grasshopper population becomes resistant to the pesticide through inheritance of resistance alleles. Other nearby grasshopper populations do not change in any noticeable way.
Consider a hypothetical insect population of 100 individuals. Two equally represented alleles (
) exist for a particular gene. Which scenario is an example of microevolution in this population?
The population doubles in size, and the two alleles are maintained at their original proportions.
The population is exposed to a toxin that kills individuals with the
allele. After exposure to the toxin the population has 25 surviving individuals, and 95% of them have the
The population is reduced in size due to loss of their food source. Fifty insects remain, and the two alleles are still present in their original proportions.
Several insects migrate to a new location. The population is left with 80 insects, but the two alleles are still equally represented.
Which choice contributes the most to genetic variation among individuals in most prokaryote species?
independent assortment of homologous chromosomes
Which condition would disturb the Hardy-Weinberg equilibrium and cause the gene pool to change?
Several homozygous recessive individuals leave the population.
Mating occurs at random.
All genotypes on average produce an equal number of fertile adult offspring.
No mutations occur.
The frequency of a particular lethal recessive allele in a population is 0.02. Given this information, calculate the percentage of individuals who are carriers of the lethal recessive allele.
Genetic drift is _____.
more likely to have an impact on small populations
an important microevolutionary mechanism in large populations
the mechanism by which new alleles originate
The Illinois populations of the greater prairie chicken benefited when managers brought in prairie chickens from other populations. This restored genetic variation to the Illinois populations through the process of _____.
a bottleneck effect
a founder effect
Which person has the highest evolutionary fitness?
a woman who lives for 105 years and has no children
a man who lives to be 68 and has 7 children and 15 grandchildren
a man who can run a marathon in less than 3 hours
a woman who lives to be 78, has 10 children, but no grandchildren
This figure is an example of _____ because it shows _____.
stabilizing selection … a population in which individuals at both extremes of a phenotypic range have been selected for
directional selection … a shift in the overall makeup of a population toward one phenotypic extreme
disruptive selection … a shift in the overall makeup of a population toward one phenotypic extreme
stabilizing selection … a favoring of an intermediate variant
What usually occurs during intersexual selection?
Males usually choose females with whom to mate.
Males fight with other males for access to females.
Neither males nor females participate in sexual selection rituals because they are costly to overall survival.
Females usually choose males with whom to mate.
Which example below presents a
about how antibiotic resistance develops?
If people do not take the full antibiotic treatment as prescribed, some microbes carrying the potential for resistance will survive and prosper.
Individual bacteria and viruses become immune to antibiotics after they are exposed to them. Eventually the antibiotics are useless.
Antibiotics are often added to livestock feed. This selects for antibiotic resistance in bacteria found in and around livestock facilities. Thus, many meat products sold in supermarkets contain antibiotic-resistant bacteria.
Heavy use of antibiotics in hospitals produces selection pressure for antibiotic resistance in resident bacterial populations.
Which genotype relative to the sickle-cell allele has the greatest reproductive success in regions where malaria is a common disease?
the heterozygous genotype
the homozygous recessive genotype
the homozygous dominant genotype
All genotypes have equal reproductive success.
In the normal course of evolution and adaptation, what is the most likely way for wings to develop in a tetrapod (four-limbed organism)?
A new, third pair of limbs will form. Unlike the other four limbs, these wings will have a lightweight skeletal structure that is designed "from scratch" and is perfectly suited for supporting flight.
The forelimbs (or hind limbs) will be used for the new purpose of flight. Natural selection will totally rearrange the elements of the skeleton to perfect the limb for its new function as a wing.
The forelimbs (or possibly hind limbs) will be used for the new purpose of flight. This new function will arise through many gradual and uncertain steps, and there will be aspects of the wing that reflect its history and are not perfectly suited for flight.
A major mutation will produce new limbs, called wings, with a skeletal structure suited to flight. If this does not happen, flight cannot be achieved.
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