AP Biology Semester I Exam Flashcards
“Improving the intelligence of an adult through education will result in that adult’s descendants being born with a greater native intelligence.” This statement is an example of
Lamarckism
In evolutionary terms, the more closely related two different organisms are, the
More recently that shared a common ancestor
Natural selection is based on all of the following except
Individuals adapt to their environments and, thereby, evolve
Which of the following represents an idea Darwin took from the writings of Thomas Malthus?
Populations tend to increase at a faster rate than their food supply
Which statement about natural selection is most correct?
Well-adapted individuals leave more offspring, and thus contribute more to the next generationʹs gene
Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
- Differential reproduction occurs
- A new selective pressure arises
- Allele frequencies within the population change
- Poorly adapted individuals have decreased survivorship
2, 4, 1, 3
To observe natural selection’s effects on a population, what must be true?
One must observe more than one generation of the population
The population must contain genetic variation
During drought years on the Galapagos, small, easily eaten seeds become rare leaving only large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, then what should one expect to result from natural selection?
More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent
Which of the following statements is not an inference of natural selection?
Subsequent generations of a population should have greater proportions of individuals that possess traits
Which of the following is the best example of humans undergoing evolution, understood as “descent with modification?”
Reduction in the amount of amount and coarseness of body hair over millennia
If two modern organisms are distantly related in an evolutionary sense then one should expect that
They should share fewer homologous structures than two more closely related organisms
Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?
All organisms use essentially the same genetic code
Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails just as fish do, even though their closest relatives were terrestrial reptiles that had neither dorsal fins not aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are
Examples of convergent evolution
Adaptions to a common environment
The theory of evolution is most accurately described as
An overarching explanation, supported by much evidence, for how populations change over time
What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trait?
The two phenotypes are about equally adaptive under laboratory conditions
Which of the following is not a requirement for maintenance of Hardy-Weinberg equilibrium?
An increasing mutation rate
In which population would it be least likely that an accident would significantly alter the frequency of the brown allele?
B
Which population is most likely to be subject to the bottleneck effect?
A
In a large, sexually reproducing population, the frequency of an allele changes from 0.6 to 0.2. From this change, one can most logically assume that, in this environment,
The allele reduces fitness
If a particular phenotypic variation lacks a genetic component, then
Natural selection cannot act upon it to make a population better adapted over the course of generations
When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism
Leaves more viable offspring than others of its species
Fossil evidence indicates that horses have gradually increased in size over geologic time
Directional selection
The average birth weight for human babies is about 3 kg. Fewer are born with lower or higher birth weights.
Stabilizing selection
A certain species of land snail exists as either a cream color or solid brown color. Intermediate individuals are relatively rare.
Disruptive selection
What is true of the trait whose frequency distribution in a large population appears above? It has probably undergone
Stabilizing selection
Male satin bowerbirds adorn structures that they build, called “bowers,” with parrot feathers, flowers, and other bizarre ornaments in order to attract females. Females inspect the bowers and, if suitably impressed, allow males to mate with them, after which they go off to nest by themselves. The evolution of this behavior is best described as due to
Sexual selection
A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. That the actual forelimbs of these mammals do not seem to be optimally arranged is because
Natural selection is generally limited to modifying structures that were present in previous generations and in previous species
Successfully breeding two individual organisms at a zoo and obtaining fertile offspring for several generations is no guarantee that the same could occur in nature (i.e., in the wild). Which species concept becomes difficult to confirm because of this fact?
Biological
You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?
Morphological
Males of one species sing only during rainy conditions; males of another species sing only when it is not raining
Behavioral
One species lives only in tree holes; another species lives only in streams
Habitat
Females of one species choose mates based on song quality; females of another species choose mates on the basis of size
Behavioral
One species mates for two weeks in early April; another species mates for three weeks in early May
Temporal
Males of one species are too small to perform amplexus (an action that stimulates ovulation) with females of all other species
Mechanical
Two species of frogs belonging to the same genus occasionally mate, but the offspring do not complete development. What is the mechanism for keeping the two frog species separate?
The postzygotic barrier called hybrid inviability
In an environment in which members of population compete with each other for resources, a change occurs that selects against members that exhibit a particular dominant trait (the trait exhibits complete dominance). Which graph best depicts the trends in genotypic frequencies that would be expected to occur over time?
Graph B
A defining characteristic of allopatric speciation is
Geographic isolation
The Galapagos archipelago appeared about 2 million years ago, when submerged volcanoes (seamounts) rose above the ocean’s surface. A single hypothetical colonization event introduced a species of finch to one island in the distant past. Today, several islands in the archipelago contain unique species of finches. What must have happened following the initial colonization event to account for the current situation?
Inheritance of acquired characteristics
Allopatric speciation
Adaptive radiation
Beetle pollinators of a particular plant are attracted to its flowers by their bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?
Sympatric speciation, habitat differentiation
Which of the following would be an example of macroevolution?
Evolution of modern humans, Homo sapiens, from australopithecine ancestors
A hypothetical mutation in a squirrel population produces organisms with eight legs rather than four. Further, these mutant squirrels survive, successfully invade new habitats, and eventually give rise to a new species. The initial event giving rise to extra legs would be a good example of
Changes in homeotic genes
The ostrich and the emu look very similar and live in similar habitats, however they are not very closely related. This is an example of
Convergent evolution
If organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?
D and F
A common ancestor for both species C and E could be at position number
4
If the sequence of Species A differs from that of the other four species due to simple misalignment, then what should the computer software find when it compares the sequence of Species A to those of the
The nucleotide sequence of Species A should have long sequences that are nearly identical to those of the other species, but offset in terms of position number.
Five conditions of Hardy Weinberg
- Large population
- No gene flow
- No sexual selection
- No natural selection
- No mutation
Which of the following is not one of the four major groups of macromolecules found in living organisms?
Glucose
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers, and hydrolysis breaks down polymers
If 128 molecules of the general type shown in the figure below were covalently joined together in a sequence, the single molecule that would result would be
Polysaccharide
Consider a polysaccharide consisting of 576 glucose molecules. The total hydrolysis of the polysaccharide would result in the production of
575 water molecules
576 glucose molecules
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
As a disaccharide
Which of the following are polysaccharides?
Glycogen
Starch
Chitin
A polypeptide can best be described as a
Polymer of amino acids
The 20 different amino acids found in polypeptides exhibit different chemical and physical properties because of different
Side chains (R groups)
The bonding of two amino acid molecules to form a larger molecule requires which of the following
Removal of a water molecule
Upon chemical analysis, a particular protein was found to contain 556 amino acids. How many peptide bonds are present in this protein?
555
The a helix and the B pleated sheet are both common polypeptide forms found in which level of protein structure?
Secondary
What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 amino acids?
The primary structure of the protein would be changed.
The tertiary structure of the protein might be changed.
The biological activity or function of the protein might be altered.
Which of the following best describes the flow of information in eukaryotic cells?
DNA to RNA to proteins
Which of the following are nitrogenous bases of the pyrimidine type?
Cytosine and uracil
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA
Contains one less oxygen atom
Which of the following statements best summarizes the structural differences between DNA and RNA?
DNA nucleotides contain a different sugar than RNA molecules
In the double helix structure of nucleic acids, cytosine hydrogen bonds to
Guanine
A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism
Is more closely related to frogs than to humans
About 25 of the 92 natural elements are known to be essential to life. Which four of those 35 elements make up approximately 96% of living matter?
Carbon, nitrogen, oxygen, hydrogen
What is the approximate atomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons?
31 daltons
Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have
20 protons
The atomic number of carbon is 6. Carbon-14 is heavier than carbon-12 because the atomic nucleus of carbon-14 contains
8 neutrons
A covalent chemical bond is one in which
Outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms
A polar covalent bond can form when
One of the atoms has a greater affinity for elections than the other of the same molecule
The ionic bond of sodium chloride is form when
Chlorine gains an electron from sodium
In a single molecular of water, two hydrogen atoms are bonded to a single oxygen atom by
Polar covalent bonds
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
Hydrophilic bond
What do cohesion, surface tension, and adhesion have in common with reference to water?
All are properties related to hydrogen bonding
Which of the following is possible due to the high surface tension of water?
A water strider can walk across the surface of a small pond
Water’s high specific heat is mainly a consequence of the
Absorption and release of heat when hydrogen bonds break and form
Which of the following solutions has the greatest concentration of hydrogen ions?
Gastric juice at pH 2
Which of the following solutions has the greatest concentration of hydroxide ions?
Seawater at pH 8
Which property of the carbon atom gives it compatibility with a greater number of different elements than any other type of atom?
Carbon has a valence of 4
What type of bond does carbon have a tendency to form?
Covalent
Which of the following statements correctly describe catabolic pathways?
They release energy as they degrade polymers to monomers
Which of the follow are true for anabolic pathways?
They are highly regulated sequences of chemical reactions.
They consume energy to build up polymers from monomers.
Which of the following is a statement of the first law of thermodynamics?
Energy cannot be created or destroyed
Which of the following statements about metabolism is incorrect?
Metabolism is a emergent property of life at the levels of organisms
Whenever energy is transformed, there is always an increase in the
Entropy of the universe
Which of the following is true for all exergonic reactions?
The reaction proceeds with a net release of energy
