The specimens are arranged in three rows that read: Bottom Row: Mussels, Giant Tubeworms, and Shrimp. Middle Row: Zoarcid Fish and Dandelion Siphonophores. Top Row: Octopuses and Blind Crabs. In the bottom row, there is one arrow from Mussels to Octopuses; there is one arrow from Giant Tubeworms to Zoarcid Fish; and there are three arrows from Shrimp to Zoarcid Fish, Dandelion Siphonophores, and Blind Crabs. In the middle row, there is one arrow from Zoarcid Fish to Octopuses; and there is one arrow from Dandelion Siphonophores to Blind Crabs. In the top row, there is one horizontal arrow from Blind Crabs to Octopuses. The food web above represents feeding relationships in a biological community near a deep-sea hydrothermal vent. Hydrothermal vents are geysers on the seafloor that gush super-heated, mineral-rich water. The seawater surrounding hydrothermal vents typically contains carbon dioxide (CO2), molecular hydrogen (H2), hydrogen sulfide (H2S), and methane (CH4). Sunlight, however, fails to reach the seafloor where deep-sea hydrothermal vents are located. As part of an investigation, researchers collected living specimens from an area near a deep-sea hydrothermal vent. Mussels in the collection were found to be dependent on molecular hydrogen in seawater. Also, the researchers discovered multiple species of bacteria living in the gills of the mussels. Mussels use gills for filter-feeding and gas exchange with the surrounding seawater. On the basis of their experimental results, the researchers hypothesized that some bacteria living in the gills of the mussels are capable of chemosynthesis. Which of the following best explains how biological communities near deep-sea hydrothermal vents can exist in a habitat lacking sunlight?

Researchers were modeling the effects of repeated cycles of isolation with occasional interbreeding among five hypothetical fish species (species A, B, C, D, and E) found in two separate lakes (lakes I and II) that are occasionally joined by flooding, as shown in Figure 1. The research team indicated that species A would be considered to be the single common ancestor of species B, C, D, and E. There are two lakes and Lake Roman numeral 1 is to the left of Lake Roman numeral 2. Lake Roman numeral 1 is very small, and contains fish populations A and B. Lake Roman numeral 2 is extremely large and there are three small islands located in Lake Roman numeral 2 on the left side of the lake. The fish populations A, D, and C are along the right side of the lake in that order, and E is on the left side of the lake below the largest island. Figure 1. Current locations of populations of fish species A, B, C, D, and E Which of the following data could best support the claim that species B arose from a speciation event in Lake I?

Semalparous species reproduce only once in their lifetime. They put all their energy into one gigantic bout of reproducing ,then they die. What is the reproductive benefit of this strategy?

In the American Southwest, annually emerging cicadas are dependent upon the cottonwood trees in the floodplain. Adult male cicadas perch in the cottonwood trees and chirp to attract females. Females lay their eggs in the branches of the cottonwoods, and, upon hatching, the cicada nymphs drop to the ground, burrow into the soil, feed on the tree roots, and later emerge as adults. Other organisms in the floodplain community prey on the cicadas, as shown in the food web. Arrows extend from the cicada to a yellow billed cuckoo, a sparrow, a lizard, a wasp, a black widow, and a kestrel. An arrow extends from a cottonwood to the cicada. An arrow extends from a lizard to a kestrel. An arrow extends from a sparrow to a kestrel. An arrow extends from a yellow billed cuckoo to a kestrel. Figure 1. Food web in floodplain community Human activity has caused a decrease in the amount of flooding and an increase in the incidence of wildfires in the floodplain. In an investigation into the recent changes in the floodplain ecosystem, researchers monitored the soil temperature, amount of cottonwood ground coverage (i.e., area of the ground that is shaded by leaves), and cicada emergence for a period from mid-June until late July. The results of the investigation are represented in Figure 2 and Figure 3. The horizontal axis is labeled “Cottonwood Ground Coverage, in percent,” and the numbers O through 100, in increments of 20, are indicated. The vertical axis is labelled “Mean June Soil Temperature, in degrees Celsius,” and the numbers 18 through 28, in increments of 2, are indicated. The line of best fit is shown. The line begins at the point with coordinates 2 percent of cottonwood ground coverage comma 25 degrees Celsius and moves directly downward and to the right ending at the point with coordinates go percent cottonwood ground coverage and 19 degrees Celsius. Figure 2. Effect of cottonwood ground coverage on soil temperature The horizontal axis is labeled “Mean June Soil Temperature, in degrees Celsius,’ and the numbers 18 through 28, in increments of 2, are indicated. The vertical axis is labeled “Mean Emergence Date,’ and the dates 6 13 through 7 23, in increments of 5 days, are indicated. The line of best fit is shown. The line begins at the point with coordinates 19 degrees Celsius comma the date 7 21 and moves directly downward and to the right ending at the point with coordinates 26 point 5 degrees Celsius comma the date 6 13. Figure 3. Relationship between soil temperature and cicada emergence date To assess the impact of wildfires on soil temperature and cicada emergence, the researchers compared mean emergence dates for two natural sites where portions had been affected by wildfire. In addition, cicada emergence was monitored at an experimental site where the soil temperature was experimentally maintained. The data are shown in the table. MEAN CICADA EMERGENCE DATES AT SITES AFFECTED BY WILDFIRES OR WITH EXPERIMENTALLY CONTROLLED SOIL TEMPERATURE The table shows Mean cicada emergency dates for Natural Site 1, Natural Site 2, and Experimental Site. For Natural Site 1, the Mean Emergency Date for Unburned is July 8, and for Burned is June 18. For Natural Site 2, the Mean Emergency Date for Unburned is July 15, and for Burned is July 3. For Experimental Site, the Mean Emergency Date for 24 degree Celsius is July 14, and for 27 degree Celsius is July 5. The data from the temperature-controlled experimental plots can best be used to support which of the following conclusions about cicada development?

In an experiment, 100 mice were released into a field to which no other mice had access. Immediately after their release, a representative sample of mice was captured, their fur color was recorded, and they were returned to the field. After twenty years, a representative sample of mice was captured and the distribution of fur color was again recorded. Fur Color Initial Distribution (%) Distribution after Two Years (%) Brown 80 20 Gray 10 75 Black 10 5 Which of the following could best explain the change in fur color distribution, as shown in the table above?

mRNA Codons and Amino Acids mRNA Codons Amino Acids AGA arginine GGA glycine AGC serine GCA alanine CAG glutamine . . . . glutamine-glutamine-glutamine . . . . . . serine-serine-serine . . . Which of the following messenger RNA sequences could code for both of the two amino acid sequences above, simply by a shift in the reading frame?

There is an activator on the enhancer, and general transcription factors complementary to the activator. The DNA segment is in a u-turn shape after the enhancer, and RNA polymerase two is attached to the transcription factors and the DNA directly upstream of gene x, which makes the complex of activator, general transcription factors and RNA polymerase two span from the enhancer to directly before gene X. There is an arrow below gene X pointing away from the complex labeled expression of gene x. The figure above depicts the DNA-protein complex that is assembled at the transcriptional start site of gene X when the expression of gene X is activated in liver cells. Previous studies have shown that gene X is never expressed in nerve cells. Based on the diagram, which of the following most likely contributes to the specific expression pattern of gene X ?

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. 5′- GAC CGCAUG GUG ACG AAA UUU GGC CAU UAA – 3′ Based on the universal genetic code, which of the following represents the correct polypeptide that will result from translation of the mRNA molecule shown, beginning with the first available start codon?

Which of the following statements concerning a gene is correct?

A scientist is using an ampicillin-sensitive strain of bacteria that cannot use lactose because it has a nonfunctional gene in the lac operon. She has two plasmids. One contains a functional copy of the affected gene of the lac operon, and the other contains the gene for ampicillin resistance. Using restrictions enzymes and DNA ligase, she forms a recombinant plasmid containing both genes. She then adds a high concentration of the plasmid to a tube of the bacteria in a medium for bacterial growth that contains glucose as the only energy source. This tube (+) and a control tube (-) with similar bacteria but no plasmid are both incubated under the appropriate conditions for growth and plasmid uptake. The scientist then spreads a sample of each bacterial culture (+ and -) on each of the three types of plates indicated below. The columns show the different media on the plates starting with glucose medium, then glucose medium with ampicillin and then glucose medium with ampicillin and lactose. The rows are bacterial strain with added plasmid, also labeled positive, and bacterial strain with no plasmid, also labeled negative. The plates are labeled number one through number six, with one, two and three with positive bacteria on the media in order, and four, five and six with negative bacteria on the media in order. Plate one is bacteria with plasmid on glucose medium. Plate two is bacteria with plasmid on glucose medium with ampicillin. Plate three is bacteria with plasmid on glucose medium with ampicillin and lactose. Plate four is bacteria without plasmid on glucose medium. Plate five is bacteria without plasmid on glucose medium with ampicillin. Plate six is bacteria without plasmid on glucose medium with ampicillin and lactose If no new mutations occur, it would be most reasonable to expect bacterial growth on which of the following plates?