Integrating Concepts in Biology IIAnswer Key for Sample Exam covering Chs 16-18 on Information in populations/ecological systems

Instructions for Instructors: This sample exam KEY covering Chapters 16-18 of ICB can be used as a guide to grading. You might be looking for something more specific and because some of the questions are open-ended, other answers not provided here might also be correct. See the ICB approach to assessment guide in the Instructor Resource area for more information Lab Questions (we sometimes include lab questions as what goes on in lab is integral to learning the process of science):1. (LAB) You are a scientist observing ants at a nest. Being highly social organisms, they exhibit division of

labor, overlapping generations and cooperative care of the young. You suspect that they have derived mechanisms of communication. Design an experiment to test a specific aspect of information transmission in ants (hint: what are the functions of communication?). Assume that you have unlimited time and money, and graduate students to assist you. Fill in the sections below with information about your experiment, as appropriate.

Question: Something specific and testable, such as “how do ants find their way back to their nest while searching for food?” or “how do ants communicate information about the location of food to other ants?”

Research Hypothesis: This could be stated as a prediction. For instance, I predict that ants use a chemical signal to find their way to food or back to their nest.

Null Hypothesis: Ants do not use chemical signals or other forms of communication or information transfer to find their way to food or back to their nest.

Factors and treatment levels: A variety of different experiments could be designed; e.g., after ants walk a ways, one could attempt to disrupt any trail they made by adding a different chemical or wiping the substrate clean.

Controls: Depending upon the experiment, it could be simply unmanipulated ants or nests that are observed, or there could be some kind of sham treatment.

Subjects/experimental unit: The experimental unit might be the ant or the ant nest, but students should identify the subject of the experiment

Replication of experimental unit (sample size): There should be recognition that multiple replicates should be attempted, including using multiple individuals from multiple nests of the same species of ants, or even of different species to determine how general the phenomenon is.

Lecture questions2. (CH16) How is the variation upon which evolutionary mechanisms act produced in organisms? Discuss two

ways. Support your answer with data from Data Gallery #1.

Mutation, recombination, crossing over, and environmental variation can all cause variation in phenotypes. TABLE 16.1, FIGURES 16.2, 16.4, 16.5, 16.6, 16.7, and 16.8 show data that support each of these causes of variation.

3. (CH16) You know from your studies and from your daily life that variation of traits within populations is very common, though some traits are less variable than others. Explain two distinct causes of variation in phenotype and support your answers with data for each cause. Limit your answers to a maximum of 3 sentences each. a. Recombination can be seen in TABLE 16.1 and in FIGURE 16.5, the latter of which shows that there is

variation in blood pressure when the adducin genes are recombined, and TABLE 16.1 shows the ways in which the two genes can be recombined to produce many different combinations.

b. Environmental variation can all cause variation in phenotypes. FIGURES 16.6, 16.7, and 16.8 show data that support how environmental gradients and the presence of a predator can cause variation in several different factors.

4. (CH16) Answer the following questions regarding the MN blood group in humans from the Philippines (NOTE to INSTRUCTORS): Some of these are somewhat redundant, so use a subset).a. Explain the process of assessing whether a population is in or out of Hardy-Weinberg equilibrium.

Support your explanation with data from Data Gallery #1.

Determine the observed genotypic frequencies (FIGURE 16.9), then calculate the allele frequencies (FIGURE 16.10), then calculate the predicted genotypic frequencies under H-W using formulae in TABLES 16.2 and 16.3, and then compare observed and predicted genotypic frequencies as in FIGURE 16.11.

b. If the frequency of MM in a population is 0.7 and the frequency of MN is 0.15, what is the frequency of the M allele? Show your work and indicate any Tables or Figures you consulted in your analysis.

The frequency of M alleles (denoted p) is fMM + fMN/2 = 0.7 + 0.15/2 = 0.775. FIGURES 16.9 and 16.10.

c. How do you explain variation among populations in allele and genotype frequencies? Use the human populations in the Philippines as your example.

Variation among populations in allele and genotype frequencies can arise from isolation of populations, geographic variation, or inbreeding. Some of those factors are in effect in the Philippines (FIGURES 16.11).

d. How does knowledge of allele and genotype frequencies relate to the Big Idea of Information?

Allele and genotype frequencies represent information at the population level. An individual’s genes, and which alleles he possesses, represent information within the individual and we can study how evolution might or has occurred in a population by studying that information at both the individual and population levels.

e. Recall the relationship between allele frequencies and genotype frequencies: p = fMM + fMN/2 and q = fNN

+ fMN/2. Use these formulas and algebraic manipulation to calculate p2, 2pq, and q2.

Use TABLE 16.3 and BME 16.2 to help. p2 = fMM2 + fMM x fMN + fMN

2/4, the probability of MM in the offspring generation from Table 16.3. Similarly, 2pq = fMM x fMN + 2 fMM x fNN + fMN

2/2 + fMN x fNN, and q2 = fMN

2/4 + fMN x fNN + fNN2, the probabilities of MN and NN, respectively, in the offspring generation.

5. (CH16) Answer the following two questions regarding how experimental designs can be used to determine the effects of genes and the environment on phenotypic variation.

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a. What is the purpose of the common garden in separating out the effects of genes and the environment on phenotypic variation? Provide an example of how such an experiment can be used.By planting individuals from different environments into a common area or garden, scientists can determine the effect of genes vs. the environment. FIGURE 16.7 reveals that there was a larger amount of genetic variation in honeysuckle because even when grown in a common garden, differences existed in individuals derived from different populations. So genetic changes had occurred in the two populations.

b. What is the purpose of exclusion experiments in separating out the effects of genes and the environment on phenotypic variation? Provide an example of how such an experiment can be used.The exclusion experiment was able to determine the effect of another species on the species of interest. By excluding a predatory snail, the scientist was able to determine that a particular phenotype occurred in response to the presence of that predator. Environmental factors can alter the physical appearance of animals but only within the scope of their genetic potential. The bent shape may be rare in the absence of the predator because of a decrease in feeding efficiency, but the benefit of having this shell shape in the presence of the predator is that it increases the probability of survival (FIGURE 16.8).

6. (CH17) Provide two examples of how information transmission at the population level leads to behavioral responses. Elaborate in no more than 2 sentences for each example and support with data from Data Gallery #1.

FIGURE 17.4 shows how variation in interpulse interval in fireflies leads to variation in female responses, but females are indeed responding to the information transmission of males. TABLES 17.1 and 17.2 and FIGURE 17.7 demonstrate that information transmission of storm petrels leads to responses by other members of the species.

7. (CH17 or 18) Communication between individuals of the same species is species-specific and is not used by other species. Support or refute this statement with data from Data Gallery #1 or #2.

FIGURE 17.5 supports the notion that communication is species-specific, as female P. greeni do not respond to signals of males of other firefly species.

FIGURE 17.20 does not support that notion as pollen of a variety of species can adhere to Arabidopsis stigmas.

FIGURE 18.3 shows that individual mole cricket species sometimes respond to male calls of other species. FIGURE 18.4 shows that tachinid flies respond to male calls of several mole crickets. These examples could be used to refute the statement, as could the data in FIGURE 18.6 and TABLE 18.2 where fringe-lipped bats are attracted to calls of frogs.

Finally, FIGURE 18.16 shows that flour and meal moths can recognize the chemicals emitted by each other.

8. (CH17) Analyze the relationship between light flash interval (AKA interpulse interval) and temperature for male and female fireflies. Support your answer with data from Data Gallery #1. Limit your answer to a maximum of 4 sentences. FIGURE 17.4 shows that the IPI is longer when temperatures are colder, but that it is not a linear relationship and a polynomial equation is used to describe the relationship (or best-fit line). In addition, there is variation among the males at each temperature. There is a range of temperatures where the IPI is relatively constant, according to FIGURE 17.4A. Females respond differently to the length of the IPIs depending upon their temperature, too (FIGURE 17.4).

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9. (CH17) Scientists suspect that the storm petrel’s “grating” calls are used for what purpose(s)? Elaborate in no more than 2 sentences and support with data from Data Gallery #1.

There were two types of “grating calls,” a short version and a long version, which were the most common vocalizations used by both males and females. Grating calls were usually made from within the burrow, and each type had a varying number of syllables, depending on the individual and situation (FIGURE 17.6). When a male faces another bird in front of his burrow, he most often uses one of the grating calls, which are used either in defense of a resource if the caller is facing a male, or for courtship if the caller is facing a female (TABLES 17.1 and 17.2). Males respond with the grating call to both types of male vocalizations. Grating sounds may be a signal to other males to keep away. Wilson’s storm petrels used the grating calls (FIGURE 17.6) to advertise sexual identity, whereas males used the long grating call (#1) when they had detected another male in the vicinity.

10. (CH17) Scientists suspect that the meerkat’s “recruitment” call is used against what kind of threat? Elaborate in no more than 2 sentences for each example and support with data from Data Gallery #1.

FIGURE 17.14 shows that recruitment calls are used to gather the clan together and causes receivers of the call to erect their fur and tails, in order to make themselves look bigger to an oncoming threat. A sentinel gives a high recruit call if a snake was observed or a low recruit call if a meerkat from a rival group came near.

11. (CH17) Plant pistils exchange information with pollen grains in multiple ways. Explain how, in no more than 3 sentences, using data from Data Gallery #1 to support your answer.FIGURE 17.17 shows the steps leading up to fertilization of an egg by a pollen grain; communication between the pistil and pollen grain occurs at several of these steps. FIGURE 17.20 illustrates that pollen grains adhere to the stigma, and that the information is somewhat, but not completely, species-specific. FIGURE 17.21 shows that adhesion of pollen grains and pollen tube growth is dependent upon lipid or protein signals (more the pollen tube growth than initial adhesion, according to the figure. Finally, TABLE 17.4 shows that ovules release a chemical that attracts pollen tubes to them.

12. (CH17) What is the purpose of the control in a playback experiment, and what is an example of such a control? Indicate the data that show a control and explain why it is a control, in no more than 3 sentences.The control in a playback experiment may be just “no call” or ambient noise and is used to ensure that the manipulation of playing back an actual call through a loudspeaker does not affect the organisms being studied. A variety of experiments in Chapters 17 and 18 utilized playback experiments, and controls can be found in FIGURES 17.7 and 17.12, and TABLE 17.3.

13. (CH17) Most people fail to understand how plants communicate. If anything, they will cite the colors or fragrances of flowers as the only communication produced by plants, but those lucky enough to take a course that uses ICB know better. Give three examples of plant communication that we have studied. Support your answer with data from Data Gallery #1. Limit your answer to one sentence per example.

a. FIGURE 17.20 illustrates that pollen grains adhere to the stigma, and that the information is somewhat, but not completely, species-specific.

b. FIGURE 17.21 shows that adhesion of pollen grains and pollen tube growth is dependent upon lipid or protein signals (more the pollen tube growth than initial adhesion, according to the figure. Finally,

c. TABLE 17.4 shows that ovules release a chemical that attracts pollen tubes to them.Data Gallery #1

Figure 16.1 Figure 16.2

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Figure 16.3 Figure 16.5

Figure 16.7 Figure 16.9

Figure 16.10 Figure 16.11

Table 16.1 Table 16.2

Table 16.3 Table 17.1

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Table 17.2 Table 17.4

Figure 17.5 Table 17.3

Figure 17.3A Figure 17.7

Figure 17.4 Figure 16.8

Figure 17.14 Figure 17.12

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Figure 17.21 Figure 17.20C, D, and E

14. (CHs 16, 17 & 18) In my many years of parenting, I have seen good and bad parents. A good parent exhibits behaviors that nurture the next generation. Choose three examples from the data gallery of species providing for their progeny with the assistance of information. Each example needs to come from very different species. In other words, don’t choose two or more examples from the same or closely related species. Think broadly about next generation and do not limit yourself to examples of sexual reproduction. Limit your answer to a maximum of 6 sentences total.a. FIGURE 17.14 shows meerkat communication that is used to defend against predators and other

threats. These vocalizations protect the entire clan, especially the offspring.b. Plants use information to ensure that the proper pollen fertilizes the ovule, which leads to

reproduction and production of offspring and providing for future generations (FIGURE 17.20)c. FIGURE 18.16 shows that flour and meal moths can recognize the chemicals emitted by each other,

and choose to lay eggs in situations that decrease competition among offspring.

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15. (CHs 17 & 18) For each of the following themes of information, illustrate the theme once at the population level and once at the ecological system level with data from Data Galleries 1 and 2, and write up to 2 sentences explaining how the graph or table illustrates the theme. Do not repeat an answer from another question. Try to use data that you have not already used elsewhere.

a. Imperfect information transfer produces variation.i) Population: FIGURE 17.4 shows variation in response of female fireflies to male interpulse

intervals. Or, FIGURE 17.20 shows that pollen grains of different species can adhere to stigmas of Arabidopsis.

ii) Ecological system: FIGURE 18.16 shows that flour and meal moths can recognize the chemicals emitted by each other, and choose to lay eggs in situations that decrease competition among offspring, but that there is variation in the choices that individuals make. Or, FIGURE 18.18 shows variation in settlement of coral larvae on different substrates.

b. Information can be expressed and regulated without loss of content. i) Population: There are many examples. For instance, sentinel calls of meerkats lead to longer

times between guards assuming duty (FIGURE 17.12B). Recruitment calls lead to a fairly small set of behavioral responses, including gathering together, erecting fur and tails and approaching the caller (FIGURE 17.14). FIGURE 17.4 shows that most individual females can receive information from males, at least at particular interpulse intervals.

ii) Ecological system: FIGURE 17.5 demonstrates that calls of different species are not recognized by females of one species of firefly. Rate of consumption at departure for horned lizards follows predictions of optimality, suggesting that lizards are receiving and integrating information from their environment, including the resources at ant nests.

c. Non-heritable information is transmitted within and between biological systems.i) Population: Many examples; any example that shows that information from one individual is

transmitted and received by another individual and changes their behavior but is not genetic material, for instance, would count. Vocalizations, light flashes, and emitted chemicals would all count as examples.

ii) Ecological system: Again, many examples would count. The example must demonstrate that information from one individual of one species is transmitted and received by an individual of another species and changes their behavior. Again, could be vocalizations, light flashes, or emitted chemicals.

16. (CH18) Answer the following questions about mole cricketsa. What information do mole crickets convey with sound? Support your answer with data from Data

Gallery #2. Limit your answer to a maximum of 2 sentences.Location, sex, and species identity are all part of what is transmitted to other individuals. Location is seen in FIGURES 18.2 and 18.3, and the data in FIGURE 18.3 demonstrate that both sex and species is information that is transmitted by the male vocalizations.

b. Do other species use mole cricket sound information? Explain your answer. Support your answer with data from Data Gallery #2. Limit your answer to a maximum of 2 sentences. YES, parasitic flies are captured at speakers emitting male mole cricket vocalizations (FIGURE 18.4 and TABLE 18.1).

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c. Compare and contrast frog-eating bats with the mole cricket example. Support your answer with data from Data Gallery #2. Limit your answer to a maximum of 3 sentences.Both are examples of vocalizations of a species (a male of the species, specifically) attracting natural enemies, either parasitic flies (FIGURE 18.4) or predatory bats (FIGURE 18.6 and TABLE 18.2).

17. (CH18) Examine the data below in Figures 18.14 and 18.15. Do larvae or mandibular gland secretions affect pupation time and the number of eggs laid per moth in flour moths? Refer to specific figures or parts of figures to support your answer. What can you conclude from the combination of three conditions that Corbet tested that you could not conclude from any one of the conditions alone?YES, both affect the number of eggs laid per female. There is a peak number of eggs laid when number of larvae per box or glands per coverslip is intermediate than when either is low or high. If she had tested just larvae and not gland secretions, she could not have concluded that a chemical signal was involved. Removing the larvae before females were allowed to lay eggs or adding just the secretions allowed her to determine that there were secretions and also where they came from in the larvae.

Figure 18.14 Figure 18.15

18. (CH18) Provide two examples of how information transmission at the ecological system level leads to behavioral responses. Support your answer with data from Data Gallery #2 and elaborate in no more than 3 sentences.The example must demonstrate that information from one individual of one species is transmitted and received by an individual of another species and changes their behavior. Again, could be vocalizations, light flashes, or emitted chemicals all could be used by natural enemies or competitors in determining where to find food, where to avoid laying eggs, etc.

19. (CH18) Explain why a short travel time between patches of food resources leads to the prediction in the marginal value theorem that a forager will spend less time in a patch feeding, even when there is plenty of prey left in the patch upon leaving. Answer in 2 sentences.

It does not take long to get to a new patch and when entering a new patch, instantaneous rate of consumption will be very high. During traveling between patches, consumption rate is zero, so to maximize the average rate of consumption over total time foraging (actually eating ants plus time spent traveling) the forager assesses its environment and “knows” it can do better by leaving a rich patch early

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if it doesn’t take long to get to the next rich patch. Overall, in that environment average rate of consumption will be higher than in a habitat where travel time between patches is long.

20. (CH18) In the space provided below, sketch a picture that shows when a horned lizard should stop feeding at one ant nest and move onto the next one. In your diagram, you must indicate:

a. the average time it takes to travel between nests

b. the average time when a lizard should leave.

c. Explain in a maximum of two sentences what the response of a lizard would be if the ant density of each nest doubled. The graph should look something like the graph on the right, although it may only have one scenario. Two are shown on the right, with two different patch qualities and one travel time between patches. Time 0 on the x-axis is when the forager enters the patch. With the same travel time, you can demonstrate that optimal foraging theory predicts that foragers should leave the dense patch earlier, a result that might be counterintuitive.

21. (CH18) Are there any species of algae for which coral settlement is significantly different from settlement on the abiotic tile surface? Support your answer with data from Data Gallery #2. Can you develop a hypothesis to explain this result?FIGURE 18.18 indicates that at least one species, Species E, has coral settlement that is significantly different from the abiotic tile surface. Species E may emit some kind of chemical that inhibits or deters coral from settling on it.

22. (CH18) Consider the effects of various predators on tadpole communities. Did the two predator species that affected diversity the most have the same effect on all prey species? If not, what were the differences? Support your answers with data from Data Gallery #2.Two predators, the minnow and the sunfish, affected diversity the most. The effect was to eliminate or almost eliminate two of the three prey species. However, the effect was different in that the lone species that survived was different for each predator (FIGURE 18.22), indicating that the predators foraged differently, had different prey detection abilities, or the prey had different predator detection abilities.

Data Gallery #2Figure 18.3 Figure 18.4

Figure 18.6 Figure 18.16 Figure 18.7B

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Table 18.3 Table 18.1.

Figure 18.10

Figure 18.18 Figure 18.22

Table 18.2

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