Ap Biology 22-23 – Flashcards

With what other idea of his time was Cuvier's theory of catastrophism most in conflict? A) gradualism B) the fixity of species C) island biogeography D) uniformitarianism E) the scala naturae

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? A) Characteristics acquired during an organism's life are generally not passed on through genes. B) Spontaneous mutations can result in the appearance of new traits. C) Only favorable adaptations have survival value. D) Disuse of an organ may lead to its eventual disappearance. E) If the giraffes did not have to compete with each other, longer necks would not have been passed on to the next generation.

Which of these conditions should completely prevent the occurrence of natural selection in a population over time? A) All variation between individuals is due only to environmental factors. B) The environment is changing at a relatively slow rate. C) The population size is large. D) The population lives in a habitat where there are no competing species present.

What was Darwin's initial definition of evolution A) Natural selection B) Gradual genetic mutation C) "a descent with modification" D) "survival of the fittest"

Where are fossils often found? A) In the ocean B) In sedimentary deposits C) In glaciers D) In volcanic rock

Which scientist proposed a novel hypothesis appertaining to the use and disuse of features and the inheritance of acquired characteristics? A) Lamarck B) Linnaeus C) Darwin D) Cuvier

Natural selection is based on all of the following except A) genetic variation exists within populations. B) the best-adapted individuals tend to leave the most offspring. C) individuals who survive longer tend to leave more offspring than those who die young. D) populations tend to produce more individuals than the environment can support. E) individuals adapt to their environments and, thereby, evolve.

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. A) 2 → 4 → 1 → 3 B) 4 → 2 → 1 → 3 C) 4 → 1 → 2 → 3 D) 4 → 2 → 3 → 1 E) 2 → 4 → 3 → 1

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true? A) The amount of available food may have increased. B) The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight. C) The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive. D) Three of the statements above are correct. E) A and C are correct.

Which of the following must exist in a population before natural selection can act upon that population? A) genetic variation among individuals B) variation among individuals caused by environmental factors C) sexual reproduction D) Three of the responses are correct. E) Two of the responses are correct.

If Darwin had been aware of genes, and of their typical mode of transmission to subsequent generations, with which statement would he most likely have been in agreement? A) If natural selection can change one gene's frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones. B) If an individual's somatic cell genes change during its lifetime, making it more fit, then it will be able to pass these genes on to its offspring. C) If an individual acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will be the result. D) A single mutation in a single gene in a single gamete will, if perpetuated, produce a new species within just two generations.

Which of these variables is likely to undergo the largest change in value as the result of a mutation that introduces a brand-new allele into a population's gene pool at a locus that had formerly been fixed? A) average heterozygosity B) nucleotide variability C) geographic variability D) average number of loci

Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence? A) mutation B) nonrandom mating C) genetic drift D) natural selection E) gene flow

In modern terminology, diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution? A) mistakes in translation of structural genes B) mistakes in protein folding C) rampant changes to the dictionary of the genetic code D) binary fission E) recombination by crossing over in meiosis

The higher the proportion of loci that are "fixed" in a population, the lower is that population's A) nucleotide variability only. B) genetic polyploidy only. C) average heterozygosity only. D) nucleotide variability, average heterozygosity, and genetic polyploidy. E) nucleotide variability and average heterozygosity only.

In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because A) the population is diploid. B) heterozygotes can come about in two ways. C) the population is doubling in number. D) heterozygotes have two alleles.

Hardy-Weinberg equilibrium must occur in populations wherein A) an allele remains fixed. B) no genetic variation exists. C) natural selection is not operating. D) All three of the responses above are correct. E) Only two of the responses above are correct.

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the percentage of the population that is homozygous for this allele? A) 0.09 B) 0.49 C) 0.9 D) 9.0 E) 49.0

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the percentage of the population that is homozygous for this allele? A) 0.09 B) 0.49 C) 0.9 D) 9.0 E) 49.0

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population? A) 0.07 B) 0.08 C) 0.09 D) 0.70 E) Allele frequency cannot be determined from this information.

In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 36 purple-flowering plants and 64 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population? A) 0.36 B) 0.64 C) 0.75 D) 0.80

Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing A) nonrandom mating. B) geographic isolation. C) genetic drift. D) gene flow.

Sexual dimorphism is most often a result of A) pansexual selection. B) stabilizing selection. C) intrasexual selection. D) intersexual selection. E) artificial selection.

Which of the following statements best summarizes evolution as it is viewed today? A) It represents the result of selection for acquired characteristics. B) It is synonymous with the process of gene flow. C) It is the descent of humans from the present-day great apes. D) It is the differential survival and reproduction of the most-fit phenotypes.

Which of the following is most likely to produce an African butterfly species in the wild whose members have one of two strikingly different color patterns? A) artificial selection B) directional selection C) stabilizing selection D) disruptive selection E) sexual selection