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Students subjected three samples of five different molecules to gel electrophoresis as shown in Figure 1. The three lanes of the gel are numbered 1, 2, and 3 for each of the three samples. Along the left side of the gel, from top to bottom, are the letters A, B, C, D, and E, representing the positions of the five molecules in the samples. A plus symbol is above the top of the gel, and a minus symbol is below the bottom of the gel. Open rectangles representing the sample loading wells are located in each lane, in a horizontal position between the letters B and C. Black rectangles in each represent the molecules in the samples. The data are as follows. In lane 1, there is a black rectangle at position A and a second black rectangle at position B. In lane 2, there is a black rectangle at position C and a second black rectangle at position D. In lane 3, there is a black rectangle at position E. Figure 1. Gel electrophoresis of three prepared samples Which of the following statements best explains the pattern seen on the gel with regard to the size and charge of molecules A and B?

The figure below represents a food web in a particular ecosystem. Each letter represents a species. The arrows indicate the direction of energy flow. A is arranged at the bottom of the food web with decomposers on the right. The other letters are arranged from the far left above A, starting with E, then D up and to the right, then at the top of the web above A is C, with B to the right and lower than C, but above decomposer. The letter A has an arrow pointing up to D, an arrow pointing up to C and an arrow pointing to decomposer on the right. C has an arrow to decomposer. D has an arrow pointing left to E, an arrow pointing right to C, an arrow pointing right to B and an arrow pointing to decomposer. E has an arrow pointing to decomposer. C has an arrow pointing to decomposer. B has an arrow pointing to C and an arrow pointing to decomposer. Members of which species are most likely to be omnivorous?

A tobacco plant can be made to express a gene from fireflies, resulting in the emission of light. Which of the following is the basis for this phenomenon?

The horizontal axis is labeled Species Present, and the vertical axis is labeled Nitrogen Influx in kilograms per year. On the horizontal axis, from left to right, there are evenly spaced tick marks labeled N, B, S, and S B. The vertical axis has evenly spaced tick marks labeled 300 through 600,in increments of 100. The pointover N is at about 375. Its error bar extends from about 350 to about 425. The pointover B is centered at about 375. Its error bar extendsfrom about 360 to about 405. The pointover S is centered at about 430. Its error bar extends from about 410 to about 470. The pointover S B is centered at about 510. Its error bar extendsfrom about 500 to about 530. The caption on the figure reads: Figure 1. Mean nitrogen influx plus or minus 2 times the standard error of the mean as a function of species present. N equals neither salmon nor bears present, B equals only bears present, S equals only salmon present, and S B equals both salmon and bears present. Figure 1. Mean nitrogen influx ±2SEẍ as a function of species present. N = neither salmon nor bears present, B = only bears present, S = only salmon present, and SB = both salmon and bears present. Pacific salmon and black bears have often been cited as examples of keystone species. Pacific salmon spawn in freshwater streams but spend most of their lives at sea. When mature salmon return to the freshwater streams to spawn, they are preyed upon by bears and other predators. When salmon migrate from their marine habitat to the freshwater streams, they bring nitrogen and other marine-derived nutrients that subsequently remain in the areas surrounding the streams—a process called nitrogen influx. In an investigation, the relationship between black bears, salmon, and influx of marine nitrogen into the area around a southwestern Alaskan stream was studied. The investigators established several test plots of the same size along the stream with the following species composition: no salmon or black bears (N), bears but not salmon (B), salmon but not bears (S), and a plot where salmon and bears interact (SB). Nitrogen influx in the different sampling areas was measured as a means of assessing the impact of the different species on the health of the ecosystem. The data are plotted in Figure 1. Which of the following most likely describes how the interaction between bears and salmon influences nitrogen dynamics in the environment?

Figure 1 compares two models of speciation, A and B. Speciation model A has 9 butterflies that begins with one lightly shaded butterfly. After this butterfly is one node that branches into two paths, one to the left and one to the right, each with 4 butterflies. In the branch on the left, the first butterfly from the bottom repeats the lightly shaded butterfly, the next butterfly in the pathway has reduced shading and the remaining 2 butterflies have no shading. In the branch on the right, the first butterfly from the bottom is a tiny bit darker than the original butterfly. The next butterfly up is slightly darker than the preceding butterfly with a medium shading, the next butterfly has a darker medium shading and the last butterfly is the darkest. Speciation model B has 6 butterflies and begins with a lightly shaded butterfly. At the first node, there is a branch to the left and to the right. In the branch on the right, the first butterfly is a heavily shaded butterfly, and the next is another heavily shaded butterfly. Taking the left branch from the first or lowest node, is another node that branches to the left and to the right. From this node, the branch on the right repeats the shading of the original butterfly and the branch on the left, the first butterfly has reduced shading and the next butterfly has reduced shading. Figure 1. A comparison of two speciation models Which of the following best explains how the ecological conditions are likely to be different in the two models?

The following questions refer to the following DNA strand and table of codons. Each triplet of DNA bases is numbered from one to seven. Triplet 1 is T, A, G, triplet 2 is T, T, C, triplet 3 is A, A, A, triplet 4 is C, C, G, triplet 5 is C, G, T, triplet 6 is A, A, C, triplet 7 is A, T, T. The figure shows the universal codon table with 4 main data rows and 4 main data columns. The left side of the table is labeled First Base in Codon, and labels the main rows, from top to bottom, U, C, A, G. The top side of the table is labeled Second Base in Codon, and labels the main columns, from left to right, U, C, A, G. The right side of the table is labeled, Third Base in Codon, and labels each of the main rows U C A G.The data in the table reads as follows: First Base U and Second Base U with Third Base U, results in U U U phenylalanine; with Third Base C results in U U C phenylalanine; with Third Base A, results in U U A leucine, and with Third Base G, results in U U G leucine. First Base C and Second Base U with Third Base U, results in C U U leucine; with Third Base C, results in C U C leucine; with: Third Base A, results in C U A leucine, and with Third Base G, results in C U A leucine. First Base A and Second Base U with Third Base U, results in A U U isoleucine; with Third Base C, results in A U C isoleucine; with Third Base A, results in A U A isoleucine; and with Third Base G, results in A U G methionine or start. First Base G and Second Base U with Third Base U, results in G U U valine; with Third Base C, results in G U C valine; with Third Base A, results in G U A valine, with Third Base G, results in G U G valine. First Base U and Second Base C with Third Base U, results in U C U serine; with Third Base C, results in U C C serine; with Third Base A, results in U C A serine; and with Third Base G, results in U C G serine. First Base C and Second Base C with Third Base U, results in C C U proline; with Third Base C, results in C C C proline; with Third Base A, results in C C A proline; and with Third Base G, results in C C G proline. First Base A and Second Base C with Third Base U, results in A C U threonine; with Third Base C, results in A C C threonine; with Third Base A, results in A C A threonine; and with Third Base G, results in A C G threonine. First Base G and Second Base C with Third Base U, results in G C U alanine; with Third Base C, results in G C C alanine; with Third Base A, results in G C A alanine; and with Third Base G, results in G C G alanine. First Base U and Second Base A with Third Base U, results in U A U tyrosine; with Third Base C, results in U A C tyrosine; with Third Base A, results in U A A stop; and with Third Base G, results in U A G stop. First Base C and Second Base A with Third Base U, results in C A U histidine; with Third Base C, results in C A C histidine; with Third Base A, results in C A A glutamine; and with Third Base G, results in C A G glutamine. First Base A and Second Base A with Third Base U, results in A A U asparagine; with Third Base C, results in A A C asparagine; with Third Base A, results in A A A lysine; and with Third Base G, results in A A G lysine. First Base G and Second Base A with Third Base U, results in G A U aspartate; with Third Base C, results in G A C aspartate; with Third Base A, results in G A A glutamate; and with Third Base G, results in GAG glutamate. First Base U and Second Base G with Third Base U, results in U G U cysteine; with Third Base C, results in U G C cysteine; with Third Base A, results in U G A stop; and with Third Base G, results in U G G tryptophan. First Base C and Second Base G with Third Base U, results in C G U arginine; with Third Base C, results in C G C arginine; with Third Base A, results in C G A arginine; and with Third Base G, results in C G G arginine. First Base A and Second Base G with Third Base U, results in A G U serine; with Third Base C, results in A G C serine; with Third Base A, results in A G A arginine; and with Third Base G, results in A G G arginine. First Base G and Second Base G with Third Base U, results in G G U glycine; with Third Base C, results in G G C glycine; with Third Base A, results in G G A glycine; and with Third Base G, results in G G G glycine. In which of the following would there NOT be a change in the amino acid sequence of the peptide coded for by this DNA?

A small number of lizards from a mainland population have been deposited on four isolated islands because of the effects of a rare strong storm. Which of the following best predicts the outcome of these lizards reproducing for many generations on the islands?

The population of Japanese sika deer in central Japan was determined each year from 2005 to 2014. The sika deer population underwent logistic growth starting at 26,000 deer in 2005 and stabilized at 58,000 deer between 2012 and 2014. Based on these data, the rmax for this population was determined to be 0.57. Central Japan contains a variety of habitats, including forests and grasslands. Sika deer benefit from the resources in grasslands more than forests; if deforestation occurred, producing more grasslands in the region, the carrying capacity for sika deer population would increase. What would the population size of sika deer be one year after the carrying capacity increased to 70,000 as a result of deforestation? Assume rmax does not change.

More than 90 percent of the nitrogenous waste that is processed and excreted by humans is derived from the breakdown of proteins. Most of the remaining nitrogenous waste material is derived from the breakdown of

Simpsons Diversity Index is a way to quantify the diversity of a community.  The equation can be written as: D = N(N-1) / ∑ n ( n– 1)  Where: D = Diversity index N = Total number of individuals of all species n = Number of individuals of a specific species   Community A has 3 species (A, B, C). There are 5 individuals of each species. (N=15) Community B has 6 species (A, B, C, D, E). There are 3 individuals each of species A, B, and C. There are 2 individuals each of species D, E, and F. (N=15) Community C has 5 species (A, B, C, D, E). There are 3 individuals each of species. (N=15)   Which community has the highest species diversity?