IB 150 All Practice Homework
Parasitoids straddle the line between parasites and predators. Parasitoid wasps lay their eggs inside or on a host. After hatching, the larvae then feed on the host without immediately killing it, and in some cases even prolong the lifespan of the host's life stage that is being parasitized. Once fully developed, the parasitoid larvae typically pupate inside or outside the host, killing the host in the process, before emerging as the adult to start the next generation. How would you designate the interaction between parasitoid and host using the +/- designation of community interactions?
+/-
Hemophilia is a genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. This results in people bleeding longer after an injury, easy bruising, and an increased risk of bleeding inside joints or the brain. Two common forms of hemophilia are caused by two distinct genes, coding for different blood clotting factors. Using genetic analyses of the remains of an offshoot of Queen Victoria's descendants, it was determined that the "Royal Disease" is hemophilia B. Specifically, they found a single-nucleotide change in the gene for clotting Factor IX that causes incorrect RNA splicing and produces a truncated, nonfunctional protein. The gene for clotting factor IX is located on the X-chromosome. The pedigree of the Royal families defending from Queen Victoria is shown below, with individuals that showed phenotypic symptoms of Hemophilia B shaded in. Remember that squares in pedigrees stand for males, and circles for females. What is the probability that George VI who is the ancestor of today's British Royals was a carrier for hemophilia B and hence could have passed the condition on to the modern royal family members?
0
A particular recessive genetic disorder is polygenic. It is caused by 2 separate, unlinked genes (Genes A and B). To have the disorder, a person must be homozygous recessive for BOTH of these genes. A mother is heterozygous for Gene A and homozygous recessive for Gene B. The father is heterozygous for gene Gene A and homozygous dominant for Gene B. If they have 2 children, what is the probability that 1 of them will have this disorder?
0.0
What is the growth rate in the year you just identified in question 7 above, given the population size of 1300 in this year and a population size of 1090 individuals as revealed by a census in the previous year? Give your answer to at least 2 decimal points!
0.1925
A woman is about to deliver triplets. If each child is the product of an independent fertilization event (i.e. fraternal twins, not identical twins), what is the probability that all of her babies will be of the same gender (i.e., she will deliver EITHER all girls OR all boys)?
0.25
Last week you were wondering what Jessica and Tom's babies might look like with respect to their eyebrows and earlobes (both Tom and Jessica have thick eyebrows, controlled by gene E, with thick eyebrows dominant to thin eyebrows, and both of them have free earlobes, controlled by gene F, with free earlobes dominant to attached earlobes). You know that Tom's mom has attached earlobes. Additionally, Tom's mom has thin eyebrows, and so does Jessica's dad. No one in Jessica's pedigree going back to her great grandparents are known to have had attached earlobes, so you assume that she must be homozygous for this trait. If your inferences based on their known pedigrees are correct, what is the probability that Jessica's and Tom's first baby will have free earlobes and thin eyebrows?
0.25
You select different yellow canaries from your F2 generation (offspring from the correct Punnett Square two questions up), and you cross each of them with an F1 individual (remember those were double heterozygous individuals for all genes) several times to produce a decent number of offspring for each cross. Interestingly, you observe that the resulting phenotypic ratios from your crosses differ. Depending on which yellow F2 canary you chose for your cross you get one of 5 different outcomes. After thinking about these results for a while, you realize based on your previous work that there are actually different mechanisms for a canary to end up with yellow plumage. Either the canary is homozygous recessive for gene A, in which case it is not capable to produce any darker pigment. Or it can produce the pigment, but it is homozygous recessive for gene B, and hence the resulting pigment is never inserted (expressed) in the developing feathers. For each of the 5 possible outcomes resulting from a cross of a yellow F2 canary with a pied F1 canary, identify which mechanism was responsible for the plumage color in your yellow F2 parent that you used in the cross. Hint: Start by solving the Punnet Square for Hypothesis 3 two questions up to identify the five different genotypes of yellow Canaries among the F2 generation that you are crossing with the double heterozygous individual from the F1 generation. Then set up each of the five crosses to determine the phenotypic ratios. Then determine which of the two genes caused the yellow parent in the cross you just did to be yellow, and match this answer to the phenotypic ratio you just found in your cross.
1/2 pied : 1/2 yellow among offspring → F2 is yellow because it is homozygous recessive for gene B 3/8 pied : 5/8 yellow among offspring → F2 is yellow because it is homozygous recessive for gene B 1/4 green : 1/4 pied : 2/4 yellow among offspring → F2 is yellow because it is homozygous recessive for gene A 1/4 pied : 3/4 yellow among offspring → F2 is yellow because it is homozygous recessive for gene A AND gene B 1/8 green : 2/8 pied : 5/8 yellow among offspring → F2 is yellow because it is homozygous recessive for gene A
In cats, the Manx (M) allele causes a short or absent tail, while a recessive allele (m) confers a normal, long tail. Cats of genotype MM are never born alive, as the M allele is fatal before birth when homozygous, because the spinal cord never develops. If 2 Manx cats mate, what proportion of living offspring will have long tails?
1/3
In class, we determined that the larger insect was not able to achieve a sufficient rate of diffusion from point X to point Y in its tracheal satisfy the oxygen demand of its cells without increasing the cross-sectional area of its tracheal tubes. The variables of Fick's Law that we determined for our larger insect with thin trachea is shown in the table below: Assuming that the cells of the insect require an oxygen supply of 2.0 * 10-6 mL/min (= 0.000002), use Fick's Law to determine what the cross-sectional area (A) of this larger insect has to minimally be in µm2 to maintain the minimal rate of diffusion of oxygen of 2.0 * 10-6 mL/min. Round your answer to the nearest full µm2.
110
As recently as 1996, the black-footed ferret, North America's only native ferret species, was listed as "extinct in the wild", with only captive individuals surviving in zoos and captive rearing programs. In 2002, 223 ferrets were released in Wyoming in an attempt to re-establish a wild population. Of these only 68 individuals survived the winter into 2003. By 2010, conservation biologists counted 760 ferrets, with an estimated annual growth rate of 0.35, one of the highest of any endangered species managed under the Endangered Species Act. The status of black-footed ferrets will be reevaluated and potentially downgraded from "critically endangered" to "endangered" once their population size exceeds 2000 individuals. Assuming no change to their annual growth rate in 2010, in what calendar year (in AD) would this occur?
2014
Use this representation to answer the following question. DNA transcribed (template) strand 5' ___________________________ 3'DNA non-transcribed (sense) strand 3' ___________________________ 5' Given the locally unwound double strand above, in which direction does the RNA polymerase move while transcribing DNA?
3' → 5' along the transcribed (template) DNA strand
How many trophic levels are represented by the food web shown in panel a) of question 8?
5
Check the mRNA and amino acid sequence in the figure above. Which of the following mRNAs represents an alternative mRNA sequence that will not change the amino acid sequence as a consequence of the redundancy of the genetic code?
5'-AUG-GCU-AAC-GAU-UUC-CAG-UAA-3'
For the Punnett square in the previous question, what proportion of the offspring have a phenotype that is DIFFERENT from the phenotype of either parent? Assume that capital letters represent the dominant allele and that the genes are on different chromosome types.
7/16
Leaves are the main organs of gas exchange for plants. While plants require oxygen for cellular respiration just like any other organism, plants are autotrophs (literally: 'self-feeders') that produce their own organic molecules (a simple sugar, called D-glyceraldehyde 3-phosphate) during photosynthesis. During photosynthesis, plants need a ready supply of the gas CO2 from the atmosphere as the source of carbon to manufacture this sugar, which is the main limiting respiratory gas for plants. The leaf surface is covered with a waxy cuticle that prohibits water loss, but also gas exchange. During gas exchange, CO2 has to diffuse from the atmosphere outside through the only available openings, called stomata (located between guard cells that control the size of the stomatal opening between them) through the air space of the spongy mesophyll layer and to the palisade mesophyll cells, which are the main sites of photosynthesis. When calculating the rate of CO2 diffusion in plant leaves using Fick's Law, we have to calculate the rate of diffusion for the distance through the stomatal opening separately from the distance through the air space of the mesophyll layer. Which variable differs systematically for the two distances that requires us to consider the rate of diffusion for these two layers separately?
A
There are many different species of marine annelid worm. Some are very small, only a few millimeters in length. Others, such as lugworms, are much larger. Lugworms live in U-shaped burrows that they build in the sediment of shallow marine intertidal zones. Which variable does presence of gills most affect in lugworms?
A
What does this structure represent on a molecular level?
A single, double-stranded molecule of DNA in the condensed state
Consider the wild-type DNA sequence: 3' ATACTTTCA 5'. (Only the transcribed strand is shown). Which of the following shows an indel mutation of the wild-type DNA sequence shown above that does NOT result in a frameshift mutation? (Only the transcribed strand of the mutated sequence is shown. Inserted bases are in bold. Deleted bases are indicated by ' ).
ATA[''']TCA A[''']TTTCA
Consider the following wild-type double-stranded DNA sequence: 5' T A T G A A A G T 3' non-transcribed strand (sense strand) 3' A T A C T T T C A 5' transcribed strand In the space below, write ONE of the possible DNA sequences of the transcribed strand shown above that results from BOTH a single substitution mutation of the first codon that would also cause a nonsense mutation. Use the mRNA codon chart in the Appendix of your manual to help you.
ATTCTTTCA
Each of the following are true statements about changes that occurred between 1800 and 1950 AD. Select one or more that could account for the direction of change in the population growth rate you calculated in the previous question.
Advances in medicine led to a dramatic reduction in mortality, particularly infant mortality. Advances in mechanized farming and pest control resulted in rising crop yields per acre (more food grown per farmed acre). Technological advances, particularly in irrigation technology and industrial production of fertilizers, allowed for expansion of agriculture onto land that was previously unsuitable for growing of crops.
Based on her data, what did Abigail conclude enabled the fish to maintain this relationship of respiratory surface area to body volume during the fish's growth?
As the body of the fish grows, its gill surface area has to increase much faster than predicted for the SA/V ratio of a body of the same shape so that its gill surface area doubles when its body volume doubles during growth.
Given the diagram below, between which pair of genes would you expect to observe the lowest frequency of recombination of alleles?
Between genes A and B
Elk and bison are both herbivores and engage in exploitative resource competition. Which of the following could be explanations (reasonable hypotheses) as to why both species persist in Yellowstone rather than one of the two species being extirpated due to competitive exclusion. Use the food web shown in the previous question to help with your answer.
Both species are kept well below their carrying capacities by predators. Their fundamental niches do not completely overlap.
There are many different species of marine annelid worm. Some are very small, only a few millimeters in length. Others, such as lugworms, are much larger. Lugworms live in U-shaped burrows that they build in the sediment of shallow marine intertidal zones. Lugworms create a unidirectional water current that runs through their U-shaped burrows. Why does this allow lugworms to establish a countercurrent oxygen exchange in their gills?
Capillaries in gills can be consistently directed to run blood in the opposite direction as external water flow
After Alessandro collected some data, he finds that the carp data are most similar to Line B in the previous question, i.e. that the relationship of gill surface area and volume in carp is similar to that of trout. Which of the following hypotheses may be possible explanations that are consistent with the data and that Alessandro can set out to test next in his carp study system?
Carp have a higher concentration of hemoglobin in their blood than trout do., Carp have a lower metabolic energy requirement than trout do., Carp experience higher oxygen concentrations in their environment than previously assumed.
Prof. Chris Cheng is a molecular physiologist in Integrative Biology who studies a group of Antarctic fish called icefish. Some species in this group are unique in that they are the only vertebrates known who lack red blood cells and the respiratory pigment hemoglobin. Below are some additional observations about icefish. Match each of these observations to a relevant parameter (variable) that could help explain how these curious fish can maintain sufficient oxygen supply to satisfy their metabolic demand despite the lack of respiratory pigments.
Cold water can dissolve more oxygen than warm water. → high Phigh (high concentration) Icefish have no scales in their skin, and can hence use their skin as a respiratory surface. → high A (area) Ice fish have an unusually high volume of blood compared to their body weight. → high rate of O2 transport via bulk flow Icefish only live in water near the freezing point. → low metabolic demand for oxygen Ice fish contain a protein in their blood that acts as an antifreeze. → does not explain meeting metabolic demand for oxygen Some species of icefish are nearly transparent because they also lost the muscle pigment myoglobin. → does not explain meeting metabolic demand for oxygen
Respiratory surfaces must always stay moist (be covered by a very thin film of water). Diffusion across dry surfaces is exceedingly slow. Which variable of Fick's Law is most likely responsible for this?
D
The figure below shows the simplified diagram of the insect respiratory system that we used to model its supply of oxygen to its cells via diffusion. Why did we have to divide the entire length that an oxygen molecule has to traverse via diffusion from the external atmosphere to inside the mitochondria of a body cell into two distances, and calculate the rate of diffusion separately for the distance X-Y and Y-Z?
D differs for the two distances
In class, we oversimplified the insect respiratory system a bit to make our lives easier for calculating Fick's Law variables. For example, as in any respiratory organ, the actual respiratory surfaces where the tips of the tracheoles make contact with individual cells of the insect are moist and filled with water. When the insect becomes active and its muscle cells have a greater demand for oxygen as a result, this water gradually pulls out of the tracheoles and into the muscle cells again (see figure above). What might the benefit of this be to the insect?
Decreases the part of the distance filled with a medium that has a lower diffusion coefficient to increase the diffusion rate at times of high metabolic demand for oxygen.
Which of the following statements is true? Select one: a. A population that is experiencing density-independent growth levels off at the carrying capacity. b. Density-independent growth is more likely to occur in large than in small populations. c. Density-independent growth can continue indefinitely in nature. d. Density-independent growth results in exponential population growth.
Density-independent growth results in exponential population growth.
In discussion this week you saw the inheritance of coat colors in labrador retrievers, where two genes (gene E and gene B) interacted with each other epistatically to produce the three coat color phenotypes as shown in the following diagram: Below is the pedigree of a famous black labrador retriever female, called "Belquest's Last Laugh" (BLL). She is the ancestor of many black labrador retrievers found in the United States today. Parts of her pedigree are known as shown below: Based on the phenotypes of her and her ancestors, what was the genotype of Belquest's Last Laugh? (Leave any alleles you cannot determine with certainty blank).
E_ Bb
The graph above shows the total biomass of seeds of different size classes that are produced per m2 in an average year on the island of Santa Cruz. The data are color coded so you can see which type of seed contributes to the biomass of each size class of seeds. The two finch species (G. fuliginosa and G. fortis) each engage in the seed equivalent of "prey switching", where they always go to the seed size class first that maximizes the amount of food the finch gets per amount of time invested in searching and processing food. Identify the favored seed type that each species will turn to first. To identify the favored food type, look at the seed size classes that are most consumed when the two finches are not competing (on the islands where they exist in isolation) as shown in the graph in question 12.
Geospiza fuliginosa → Seed type 3 Geospiza fortis → Seed type 3
Which seed types are available to each species after their preferred seed type has been exhausted (based on the answer to the previous question)? This represents the realized niches in this environment after competition over shared food resources between the two species occurred for some time.
Geospiza fuliginosa → Seed types 1 & 2 Geospiza fortis → Seed types 4, 5, & 6
Which of the 5 hypotheses in the preceding question would result in gametes of at least one parent that are very likely NOT produced in equal frequencies?
Hypothesis 4
Hypothetically, brown color (B) in naked mole rats is dominant to pink color (b). Suppose you ran across a brown, male naked mole rat in class and decided to find out if he was genotype BB or Bb. You investigate this question by crossing this male with a female and observe the phenotypic ratio of offspring. a) What would be the best mole rate phenotype and genotype to mate with the male so you can make a reliable determination of the genotype of the father? Phenotype: blank Genotype: blank b) What is this cross called? blank c) What are the expected genotypic ratios from this cross? if the brown male is genotype BB: blank if the brown male is genotype Bb: blank d) What are the expected phenotypic ratios from this cross? if the brown male is genotype BB: blank if the brown male is genotype Bb: blank
Hypothetically, brown color (B) in naked mole rats is dominant to pink color (b). Suppose you ran across a brown, male naked mole rat in class and decided to find out if he was genotype BB or Bb. You investigate this question by crossing this male with a female and observe the phenotypic ratio of offspring. a) What would be the best mole rate phenotype and genotype to mate with the male so you can make a reliable determination of the genotype of the father? Phenotype: [white] Genotype: [bb] b) What is this cross called? [test cross] c) What are the expected genotypic ratios from this cross? if the brown male is genotype BB: [1:0] if the brown male is genotype Bb: [1:1] d) What are the expected phenotypic ratios from this cross? if the brown male is genotype BB: [1:0] if the brown male is genotype Bb: [1:1]
Which of the following statements about a population experiencing logistic growth is true? Select one: a. If the values for N and K are far apart, the population will grow very slowly. b. If the values for N and K are similar, the amount of available resources is high. c. If N is greater than K, the population size will decline. d. If N is less than K, the population will not grow.
If N is greater than K, the population size will decline.
For plants, obtaining CO2 by diffusion through stomata into the leaf is directly linked to water loss due to evaporation and subsequent diffusion through stomata out of the leaf. Plants can prevent water loss by partially or fully closing the stomatal opening using the guard cells that surround the openings. However, this sets up a trade-off for the plant, because closing stomata also reduces diffusion of CO2 into the leaf, and hence reduces the plant's rate of photosynthesis & growth. The relationship is important to understand in light of ongoing climate change to understand the impact of changes in CO2 concentration in our atmosphere due to burning of fossil fuels and predicted increases in drought conditions on our ability to grow enough food for a growing world population. Prof. Lisa Ainsworth is a plant physiologist and geneticist in Integrative Biology. Dr. Ainsworth has earned international recognition for her work at the SoyFACE experiment at the University of Illinois, looking at the combined effect of increasing CO2 concentrations in the atmosphere and increasing drought frequency as a direct result of these changing atmospheric CO2 concentrations on plant photosynthesis. FACE stands for Free Air Carbon Enrichment, which alludes to the ability in this experimental set-up to increase the CO2 concentration of the air inside the experimental rings in fields to be increased to future expected values, like those anticipated by the year 2050. It was initially predicted that as atmospheric CO2 concentrations rise, plants would be less prone to evaporative water loss, making plants more drought resistant. However, when experimentally raising CO2 concentrations to anticipated AD 2050 levels, while at the same time exposing plants to the increased drought conditions expected by mid-century due to climate change, Dr. Ainsworth is finding a sharp reduction in photosynthetic rate, resulting in reduced growth rate, and predicted loss of food production in crop plants as the climate and atmospheric CO2 concentrations continue to change. What is a likely explanation for this observation?
Increased drought conditions forced plants to reduce the variable 'Area' in Fick's Law to avoid water loss to a degree that reduced diffusion rates of CO2 below today's values despite the higher atmospheric CO2 concentrations.
Years pass, and Jessica and Tom just had a kid, and they send you a picture of the three of them. You are surprised to see that the baby has thin eyebrows and attached earlobes. What does this tell you?
Jessica's genotype must be Ee Ff. At least some of Jessica's direct ancestors must be carriers for the recessive allele of gene F, including at least one of her parents. Given what you know now about Jessica and Tom's genotypes after seeing their first baby, you realize that prior to inception, the chances of their child showing the thin eyebrow, attached earlobe phenotype was only 1/16.
Alessandro starts a project to better understand carp gill anatomy. He knows that the brook-trout in the previous question live in highly oxygenated mountain streams. In contrast, carp are bottom-dwelling fish in lakes that live in water that has a much lower oxygen concentration. Alessandro would like to use Abigail's data on brook trout to make some predictions about carp gills before collecting data. Knowing the difference in oxygen concentration in their environment, and assuming everything else in carp is equal to the brook trout example, which of the dotted lines shows the predicted relationship of body volume to gill surface area in carp in comparison to the brook trout relationship (thin solid line)?
Line A
What was the last phase of the cell cycle or type of cell division that resulted in the karyotype of this cell depicted above?
Meiosis I
Most of the genetic material of eukaryotes is located in the blank of the cells. The blank of the organism is organized on linear pairs of blank , each of which consist of a long, unbroken blank molecule of blank whose sequence of blank carries the genetic information to make blank . Hence, it is the action of the proteins encoded by your blank that links your unique set of genetic information, your blank , to your physical, observable blank .
Most of the genetic material of eukaryotes is located in the [nucleus] of the cells. The [genome] of the organism is organized on linear pairs of [chromosomes], each of which consist of a long, unbroken [double‑stranded] molecule of [DNA] whose sequence of [nucleotide bases] carries the genetic information to make [proteins]. Hence, it is the action of the proteins encoded by your [genes] that links your unique set of genetic information, your [genotype], to your physical, observable [phenotype].
Which of the following statements about mutations are true? a. A substitution mutation can lead to a frameshift. b. Mutations are the only source for the origin of new alleles. c. Indel mutations that occurred in an exon (translated part of the gene) can be silent. d. Both substitution and indel mutations could result in a non-sense mutation in the affected codon following the mutational event.
Mutations are the only source for the origin of new alleles. Both substitution and indel mutations could result in a non-sense mutation in the affected codon following the mutational event.
The house cat (Felis catus) is not native to North America. House cats whose diet is supplemented by human owners and that are given access to the outdoors (outdoor cats) are having a devastating effect on native songbird populations in North America, killing anywhere from 1.4 billion to as many as 3.7 billion (yes you read that right, that is billion with a B!) birds in the continental U.S. each year. Each of the following are true statements. Which of these are possible reasons why the impact of the outdoor cat population on the longterm viability of songbird populations is likely worse than the impact of native, wild predators of birds?
Native predator populations will fluctuate with prey abundance, reducing predation pressure when prey populations become smaller; outdoor house cats maintain a much larger population size than if they relied solely on birds as prey, and their population does not decline regardless of the size of their prey populations due to feeding by owners.
What is one reason that organisms have to maintain homeostasis (maintaining a relatively stable internal environment that differs from the external environment)?
Organisms have to perpetually keep themselves out of equilibrium with the environment.
Canaries are popular pets and easy to breed in captivity. Additionally, they display great phenotypic diversity, which allows you to do some interesting genetic investigations with them. When you take a canary from a true-breeding green strain and cross it with a canary from a true-breeding yellow strain, all offspring display the pied phenotype. Based on this you suspect that (Hypothesis 1): this color variation is inherited by a gene with a co-dominant inheritance pattern (showing both phenotypic traits in hybrid phenotypes). You decide to test this hypothesis. To do so, you take pairs of your hybrid F1 individuals (of pied phenotype), and cross them to produce an F2 generation. After many dozens of crosses and hundreds of offspring, you arrive at the peculiar ratio of: 3/16 green : 6/16 pied : 7/16 yellow Based on these data, what do you conclude about your initial hypothesis?
Reject my initial hypothesis.
During which part of the cell cycle is the likelihood highest that a mutational event occurs?
S-phase
What was the last phase of the cell cycle that the cell in question 3 has fully completed? (Chromosomes shown condensed only for convenience, rather than condensed state being indicative of the phase of the cell cycle. Assume that these chromosomes could be condensed or uncondensed for your answer.)
S-phase
There are many different species of marine annelid worm. Some are very small, only a few millimeters in length. Others, such as lugworms, are much larger. Lugworms live in U-shaped burrows that they build in the sediment of shallow marine intertidal zones. Ignoring surface area of gills, which of the following variables DECREASES as a lugworm grows larger?
SA/V
Which concept did you have to apply to determine the answer to the previous question?
SA/V
Which of the cell shapes in the previous question do you expect to make up the lining of your respiratory system.
Sheet
Use the following figure to help predict which process results in higher genetic variation, which process leads to more and faster offspring being produced. Then consider under which of the following scenarios each process may be most favorable. Which of the following predictions of when this algal species reproduces via its asexual versus its sexual cycle would be consistent with hypotheses on the costs and benefits of sexual versus asexual (via mitosis only) reproduction?
The alga reproduces asexually during summer months in the pond when conditions are favorable for growth. The alga begins reproducing sexually when the present environment of mature cells becomes less conducive to growth.
In the Morse code, a series of two signal types (dots and dashes) code for 26 different letters of the alphabet. How is this analogous to the genetic code?
The bases of DNA code for the more complex amino acid sequence of the proteins in cells.
How is/are the relevant variable(s) of Fick's Law optimized by the countercurrent oxygen exchange in lugworm gills?
The correct answer is: (Phigh-Plow) is re-established
Two common finch species found on the Galapagos Islands in the equatorial Pacific Ocean are the Medium Groundfinch (Geospiza fortis) and the Small Groundfinch (Geospiza fuliginosa). Both species consume seeds of grasses, herbs, and shrubs as their primary food source. The ability to manipulate and crack the seeds is related to the size and shape of the beaks of these birds. The two species co-occur on most islands of the Galapagos archipelago. However, on a few of the smallest islets only one or the other occur in isolation. G. fortis is the only ground finch found on the islet of Daphne. G. fuliginosa is the only ground finch species found on the islet of Los Hermanos.
The data shown above reveal that: 1) The fundamental niche of G. fortis spans seeds from [0.6 ‑ 1.8 mm], and its realized niche from [0.8 ‑ 1.8 mm]. G. fortis cannot feed on the [smallest] seed types. Additionally, it avoids feeding on the [largest] seed types as long as enough of the [medium] seed types are still available. This is consistent with the hypothesis that G. fortis initially avoids seeds in its fundamental niche that [have a thick coat and take longer to crack] and hence make less energy available to them for the same amount of time spent feeding. 2) The fundamental niche of G. fuliginosa spans seeds from [0.2 ‑ 1.0 mm]; and its realized niche from [0.2 ‑ 0.7 mm]. G. fuliginosa cannot feed on the [largest] seed types. Additionally, it avoids feeding on the [smallest] seed types as long as enough of the [medium] seed types are still available. This is consistent with the hypothesis that G. fuliginosa initially avoids seeds in its fundamental niche that [are small with little biomass per seed] and hence make less energy available to them for the same amount of time spent feeding.
Several species of braconid and aphelinid wasps have specialized on parasitizing one of the smallest host species of any parasitoid wasp/host relationship: aphids. Since the wasp only feeds and gains biomass during its larval stage which is completed entirely inside the body of a single host individual, this puts significant restrictions on its growth. Which of the following has to be true about braconid and aphelinid wasps and their aphid hosts?
The developing wasp can only grow to reach a lower amount of energy stored as biomass compared to the amount of energy associated with the biomass of the host, because it can maximally consume nearly 100% of the biomass represented by the body of the aphid and convert a fraction of what it consumed into its own biomass.
Why is the oxygenated blood that reaches the body cells of a fish generally at lower pressure than in a mammal?
The fish's blood does not return to the heart after acquiring O2 in the capillaries of the gills.
Severe population collapses in black-footed ferret numbers tend to occur following population declines of prairie dogs associated with outbreaks of the bacterium Yersinia pestis. (Yersinia pestis is the same rodent-transmitted pathogen that causes the bubonic plague in humans, and this pathogen was accidentally introduced to several populations of prairie dogs in the last few decades, likely from Eurasia.) Which of the following hypotheses are consistent with this observed predator-prey relationship between black-footed ferrets and prairie dogs? You may assume that the ferrets are immune to Yersinia pestis and hence not directly affected by this bacterium for this question. (In reality, ferrets can also contract and die from an infection with Yersinia pestis. However, most released black-footed ferrets are being vaccinated against this disease due to their critically endangered status, and hence show little to no mortality from this disease. Their periodic population collapses tend to be directly tied to changes in prairie dog population size).
The food web that includes black-footed ferrets is relatively linear, preventing prey-switching of the ferrets. The carrying capacity of black-footed ferrets is closely tied to the population size of prairie dogs.
In the case of two competing barnacle species, the larger species Semibalanus is able to eliminate individuals of the smaller species Chthamalus through interference competition over its entire fundamental niche by overgrowing or dislodging them as they grow larger. Which of the following could be an explanation (reasonable hypothesis) that is sufficient to fully explain why Chthamalus evades competitive exclusion within the high-tide zone?
The high-tide zone is outside the range of tolerance for Semibalanus.
Which of the following has to be true about the two species shown in the graph in the previous question?
The niche of species 1 overlaps completely with that of species 2 in the environment these data were collected in. Species 1 is competitively superior to species 2 across the full range of environmental variation encountered in the observed area where the populations size data in this plot were collected. In the absence of the other species, species 1 is more likely to maintain a higher carrying capacity than species 2.
What can you conclude about an organism that has reached equilibrium with its external environment?
The organism is dead.
A population survey of this population of black-footed ferrets in the same year you identified in the previous question found ~1300 individuals in the wild instead of your estimate of over 2000. What can you conclude happened to this population since 2010 based on a comparison of your population size estimate for this year in the previous question and the observed number?
The population growth rate declined since 2010.
When measuring the respiratory surface area of gills in brook trout, Abigail notices that the surface area grows linearly when compared to the volume of the fish as the fish grew: What relationship do the data in the graph reveal as the trout grow larger?
The ratio of gill respiratory surface area to body volume is constant (stays the same)
Why are populations of both competing species increasing at the time step indicated by the arrow?
Their population sizes are well below their carrying capacity.
Based on the figure, which statement correctly interprets the data? (clutch size is the number of eggs in the nest)
There are density-dependent effects on clutch size.
Which of the following observations would be consistent with the hypothesis that badgers engage in prey switching between mice and voles? You may reference the Yellowstone food web shown above to help answer this question.
Voles have a more stable population size (N) through time when they coexist with mice than in the absence of mice. Mice have a more stable population size (N) through time when they coexist with voles than in the absence of voles. Badgers have a more stable population size (N) through time when they coexist with both mice and voles, rather than with only one of the two species.
What is the amino acid sequence that corresponds to the following abbreviated DNA sequence taken from the middle of a gene? Note that the shown partial sequence starts in the reading frame of the gene. You may use the Messenger RNA Codon Chart. Use the single-letter codes for the amino acids found in the chart, and enter them without spaces or other symbols into the field below. 5'TATGAAAGT3' non-transcribed strand 3'ATACTTTCA5' transcribed strand
YES
Gaucher's disease is an inherited metabolic disorder in which harmful quantities of a fatty substance called glucocerebroside accumulate in the spleen, liver, lungs, bone marrow, and sometimes in the brain. Two healthy parents know from DNA sequencing of their gene that each must be a carrier for the recessive allele responsible for Gaucher's disease. a) What is the probability that the mom will donate a recessive allele to any of her offspring? blank b) What is the probability that the dad will donate a dominant allele to any of his offspring? blank c) If their first three children have the disease, what is the probability that their fourth child will not? blank d) If instead we assume that they have not yet had any children but will have 4 children in the future, what is the probability that all four children will have phenotypic symptoms of the disease? blank
[1/2] [1/2] [3/4] [1/256]
The offspring of one mated pair of mammals included three males, all of which showed an X-linked recessive trait. The fourth offspring was a female. Consider whether the following statements about her are definitely true, possible, or false. a) Even if the father shows the trait, she will not. blank b) She can only show the trait, if her father shows it phenotypically as well. blank c) If the father does not show the trait, she can still phenotypically show the trait.
a) Even if the father shows the trait, she will not. [possible] b) She can only show the trait, if her father shows it phenotypically as well. [definitely true] c) If the father does not show the trait, she can still phenotypically show the trait. [definitely false]
Which best describes the mode of inheritance in the pedigree shown below? Hint: In problems like these, solve the pedigree by identifying genotypes of all individuals shown for EACH of the inheritance patterns separately. You will find contradictions (individuals that cannot have the genotype you identified) for all except one type of inheritance pattern. The inheritance pattern that produces no contradictions must be the correct answer.
autosomal recessive
Birds engage in counter-current exchange, mammals do not. Simply based on what you know about counter-current exchange, in which group of animal would you predict to find that respiratory capillaries flow alongside respiratory surfaces over a longer length for?
birds
Mammalian lungs with the respiratory surfaces in the shape of dead-end alveoli require tidal flow to ventilate. Tidal flow is not conducive to counter-current exchange. The next two questions ask you to explore why not. When asked to demonstrate why something cannot work, an effective strategy is to model the ineffective set-up and explore what the consequences would be. Below is a diagram of what our alveoli might look like, if they were set-up to enable counter-current flow during inhalation: First, identify the concentration gradient for both inhalation and for exhalation in the hypothetical alveoli above that are plumbed for counter-current exchange during inhalation.
blood during exhalation → Phigh blood during inhalation → Plow air during exhalation → Plow air during inhalation → Phigh
In order for the four shown gametes to have been produced by meiotic divisions from the SINGLE oöcyte shown in G1-phase to the left (i.e. you are looking at the gametes produced during meiosis from a single parent cell), what must have happened during meiosis?
both non-sister chromatids of the large chromosome type had a crossing-over event between genes H and F
Carefully observe the population growth data for elk and wolves in Yellowstone national park between 1983 and 2015 in the figure above. Wolves were first introduced to the park in 1995, and were entirely absent from the park prior to that year. Assume that elk are by far the most common prey items in the wolves' diet. Match the correct years or values to each of the statements below based only on the information evident from the graphs above:
carrying capacity of elk in absence of predation → ~15,000 years with highest r for wolves → 1995-2000 years with negative r for wolves → 2005-2010, years with lowest K for wolves → 2010-2015 years with r = 0 for wolves → 2010-2015 years with d > b for wolves → 2005-2010 years with d = b for wolves → 2010-2015 years with b > d for wolves → 1995-2005 best time period to estimate rmax for wolves → 1995-2000
The phenotypic variation in the trait "coat color" in mice is passed from a parent to their offspring via _______________.
differences in DNA sequences in different parents
The different coat colors of the two mouse phenotypes are directly caused by _________.
differences in the protein amino acid sequence
There are amphibians that are even larger than bullfrogs. Which of the following could explain how such a large amphibium could obtain a sufficient rate of diffusion of respiratory gases?
different shape (e.g. flat or ribbon shaped) larger internal surface area of the lungs reduced metabolic rate (reduced rate of cellular respiration)
What is the ploidy of the cell shown above?
diploid
Niche differentiation (reduced niche overlap) with respect to seed type will be more pronounced (become apparent earlier in the year) in a:
dryer year when fewer seeds of all seed types were produced
Based on your answer to question 4, the human population grew blank between 1800 and 1950 AD.
faster than exponentially
Considering only these 2 genes, how many genetically distinct gametes can this individual produce, if genetic recombination results from BOTH crossing over and independent assortment?
four
Which of the following groups of gametes CANNOT be produced by the SINGLE shown oöcyte undergoing ONE set of meiosis (meiosis I plus meiosis II) divisions? Select all answer choices that could not have been produced via a single cell undergoing meiosis.
gamete assemblage A gamete assemblage D gamete assemblage F
Which of the groups of gametes show ALL POSSIBLE genotypes after thousands of meiotic divisions starting with the genotype of the oöcyte shown above?
gamete assemblage F
On the given Punnett square, what do the letters used as column and row headings represent (e.g., TB, Tb, tB, and tb)?
gamete genotypes
Many unicellular algal species are both capable of asexual and sexual reproduction, as illustrated in the case of one type of algae above. Based on what you know about the effects of different processes on ploidy and the information on the life cycle of an alga above, associate the most likely ploidy with each life stage of this algal life cycle.
gamete → haploid zoospore → haploid, zygospore → diploid mature individual → haploid
What is the ploidy of the depicted cell?
haploid
What is the role of each of the following structures in the mammalian respiratory system?
hemoglobin in pulmonary capillaries → supports low Plow in blood serum (liquid) hemoglobin in systemic capillaries → supports high Phigh in blood serum (liquid) bulk flow of blood from pulmonary to systemic capillary beds → supports low L capillaries forming a dense net over the alveoli → supports high A water film lining inner surface of alveoli (as opposed to dry cell surface) → supports high D
Take another look at the aphid-parasitoid food web in question 8. Based on what you know about predation and competition, under which condition do you expect braconid wasps and aphelinid wasps to stably coexist with each other in the same field? For this question, assume that each of these parasitoid wasps have no other hosts other than the one shown in the food web.
in the presence of cynipid wasps
Most food webs dominated by mammals have 3 or occasionally 4 trophic levels. Compare this observation with the trophic levels you counted in the soybean aphid-parasitoid food web. How can you explain the difference?
insects have a higher ecological efficiency than mammals
Which of the following statements is/are correct statements about a Punnett Square like the one in the question above.
it represents all the possible combinations of gamete genotypes between two individuals it is a combinatorial probability table that allows you to calculate the probabilities of genotypes and phenotypes produced in a genetic cross it is a model for the process of fertilization
Consider the following mRNA transcript:5'-UCUGAUGGGCUGAGUA-3' Assuming that this is the complete mRNA molecule, how will ribosomes translate its sequence into a polypeptide chain? Consult the messenger RNA codon chart to help you translate the mRNA sequence. Be mindful of the reading frame the ribosome will use.
methionine, glycine
Is Panel C in Question 12 more likely to show the distribution of seed types in the diet of both species on Santa Cruz early in the season (after seeds just ripened and first became available) or mid- to late-season after the two species were competing over the available seeds for some time?
mid to end of season (long after seeds were produced and after birds fed on the available seeds for several months)
Amphibians such as frogs breathe both with their lungs and via gas exchange through their moist skin. Which is likely to be able to derive a higher proportion (fraction) of its oxygen demand from gas exchange through their skin as opposed to via its lungs? Hint: consider which concept you need to consider to answer this question.
poison dart frog (one of the smallest frogs in the world)
Soybean aphids and their parasitoids are part of a rather complex drama that is playing out in miniature in the soybean fields you see any time you leave Champaign-Urbana (see panel a) above). Two different wasps (a braconid wasp and an aphelinid wasp) parasitize aphids. These two aphid parasitoids are themselves parasitized as larvae inside the aphid by a cynipid wasp (we call the cynipid wasp a hyperparasitoid, meaning it is a parasitoid of another parasitoid - it lays its eggs inside a parasitized aphid, and upon hatching its larvae consume the other parasitoid larvae - not the aphid). The cynipid wasp is itself parasitized by a second hyperparasitoid (a megaspilid wasp) whose larvae consume the pupal stage of the cynipid wasp inside the mummified aphid case. Panel b) shows data on aphid population size from a 10-year study on the effectiveness of using parasitoid wasps as a biocontrol agent of aphids. (Data from every second year shown. Note that aphids overwinter as eggs and their populations on soybeans rapidly increase each year once soybean plants emerge.). Data from year 1 shows a soybean plot covered in insect netting to prevent any parasitoids reaching the aphids. Data from year 3 shows the same soybean plot, but this time braconid wasps were introduced into the net-covered plot. Despite resulting in pronounced population cycles, the braconid wasp was able to drastically reduce aphid population size. In years 5-9 the insect netting was removed to test the effectiveness of braconid wasps in open air field conditions. Braconid wasps were again released in the field at the beginning of the summer season. However, in years 5-7, the effectiveness of the braconid wasp in controlling the aphid population was much reduced. Despite no change in treatment in year 9, the effectiveness of braconid wasp biocontrol on aphids again improved. Match the most likely changes in the food-web that could account for these data:
reduced effectiveness of the braconid wasp in controlling the aphid population in years 5 & 7 → arrival of cynipid wasps in the soybean field improved effectiveness of the braconid wasp in controlling the aphid population in year 9 → arrival of megaspilid wasps in the soybean field
Blue whales are mammals and just like us have lungs with alveoli and transport oxygen in blood via a closed circulatory system. However, in contrast to us, blue whales are the biggest animals that have ever lived. Compared to a human, the total distance that oxygen has to diffuse to reach cells in blue whales is blank , while the distance of bulk flow for oxygen in blue whales is blank .
roughly the same, larger.
The diagram of a gamete below depicts a single chromosome within a gamete. The bars spanning the chromosome indicate 2 genes. Considering only the two genes shown, which of the following processes was NOT capable to produce genetic diversity among the gametes of an individual?
sex linkage fertilization independent assortment
Match the following concepts to their appropriate relationships and functions with respect to diffusion:
the Fick's Law equation → models the rate of diffusion metabolic rate of organism → determines (in part) P1 each of the four variables in Fick's Law → affects the likelihood of respiratory gas molecules to move from point A to point B via random motions Second Law of Thermodynamics → shows that the process of diffusion is exergonic surface area to volume ratio (SA/V) → explains the relationship between the rate of supply to the rate of demand for respiratory gases
Based on your answer to the previous question, what problem prevents mammalian lungs from engaging in counter-current design? If mammalian alveoli had respiratory capillaries directed to engage in counter-current exchange during inhalation ...
the concentration gradient would reverse during exhalation and cause diffusion of oxygen from blood to the air.
Which cellular processes require chromosomes to be in their uncondensed state? a. separation of chromatids into daughter cells b. cellular respiration c. absorption of glucose from surrounding environment of cell d. transcription e. DNA replication
transcription DNA replication
Considering only the 2 genes A & B, how many genetically distinct gametes can this individual produce, if genetic recombination results from independent assortment ONLY?
two
What is a prerequisite (requirement) for counter-current exchange to function?
unidirectional flow of the outside medium (air or water) bulk flow (mass flow) of blood and external medium (air or water)
