Studied by 205 people
Which of the following statements best helps explain how the enzyme speeds up the reaction?
The enzyme’s active site bind to and stabilizes the transition state, which decreases the activation energy of the reaction
The CFTR protein is made up of 1,480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain.
Which of the following best predicts how the amino acid deletion will affect the structure of the CFTR protein?
It will affect primary, secondary, and tertiary structures of the CFTR protein.
Amylase is a protein that catalyzes the conversion of starch to simple sugars. Amylase activity in an aqueous solution can be measured by using iodine as a starch indicator. A solution containing iodine and starch will have a dark-blue color, whereas a solution containing iodine but no starch will have a light-brown color. The color change of an iodine solution from dark blue to light brown can be used to measure the rate at which starch is converted to simple sugars.
A student designs an experiment to investigate the effect of environmental pH on amylase function.
Which of the following statements best justifies the inclusion of test tube V as a control in the experiment?
It will show the color change that occurs in the absence of enzyme activity.
Which of the following best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules?
Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules.
Researchers observe that the water with the high CO2 concentration. The researchers claim that lower pH alters the structure of the enzymes of the photosynhesis.
Which of the following most likely explains how a lower pH could alter the structure of photosynthetic enzymes?
There will be additional H+ ions that can disrupt hydrogen bonds in the secondary, tertiary and quaternary structures of the enzymes.
Amylase is an enzyme that converts carbohydrate polymers into monomers. Glycogen synthase is one of the enzymes involved in converting carbohydrate monomers into polymers.
Which of the following best explains the reactions of these enzymes?
Amylase aids in the addition of a water molecule to break covalent bonds whereas glycogen synthase aids in the removal of a water molecule to form covalent bonds
Which of the following statements best helps explain the reaction specificity of an enzyme?
The shape and charge of the substrates are compatible with the active site of the enzyme
The molecular structures of linoleic acid and palmitic, two naturally occurring substances, are shown in the figure.
Based on the molecular structures show in the figure, which molecule is likely to be solid at room temperature?
Palmitic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together
Water and ammonia interact to form hydrogen bonds, as respected in the figure.
Which statement best helps explain the formation of the hydrogen bond represented in the figure?
The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.
Which of the following best describes the hydrolysis of carbohydrates?
The removal of a water molecule forms a covalent bond between sugar monomers
A researcher analyzed four different samples of macromolecules, where all macromolecules in each sample are of the same type. The researchers measured the percent of carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur atoms in each sample. The results are shown in table 1.
Which of the following claims is best supported by the data in Table 1?
Sample B contains protein
Trypsin and pepsin are enzymes that function in different areas of the digestive tract. One functions in the stomach, where the pH is between 1.5 and 3.5, while the other function in the small intestines, where the pH is between 6 and 8.
Based on Figure 1, which of the following best describes where each enzyme functions?
Pepsin works in the stomach because the optimal pH for pepsin is acidic
The diagram shows how water can adhere to the xylem in the stems of plants, which contributes to water movement in the plant. Which of the following best explains how water is able to move upward from the roots of a plant, through its xylem in the stems, and out to the leaves?
Water and the xylem are both polar. Water molecules have the ability to form hydrogen bonds with each other and the walls of the xylem.
Humans produce sweat as a cooling mechanism to maintain a stable internal temperature. Which of the following best explains how the properties of water contribute to this physiological process?
The high heat of vaporization of water allows the body to remove excess heat through a phase change of water from liquid to gas
Based on Figure 1, which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water’s surface?
Hydrogen bonds between molecules at the surface of the water provide adhesion, which supports the weight of the insect
Which of the folowing best describes how amino acids affects the tertiary structure of a protein
The interactions of the different R-groups with other R-groups and with their environment determine the tertiary structure of the protein
A culture of Spirogyra (an autotrophic alga) is maintained in a water solution containing dissolved carbon dioxide and a source of phosphates but lacking nitrogen compounds. A researcher determines the rates of the synthesis of several organic compounds found in the Spirogyra before and after several weeks in the water solution. Which of the following graphs best illustrate a likely result of the experiment?
Pyruvate kinase, a key enzyme in the glycolysis pathway, is inhibited by the amino acid alanine. The ability of alanine to inhibit the enzyme is not affected by increasing the concentration of substrate.
Which of the following best explains the mechanism by which alanine inhibits pyruvate kinase activity?
Alanine binds to an allosteric site of the enzyme, changing the shape of an of the enzymes active site
Students conducted a controlled experiment to investigate whether sawdust provides enough nutrients to support plant growth. The students separated ten nearly identical sunflower seedlings into two groups. They grew the seedlings in the first group in potting soil and the seedlings in the second group in sawdust composed mostly of cellulose. After twenty days, the students recorded observations about the seedlings in each group. The students' observations are presented in the table.
The observed differences between the groups most likely resulted from differences in the ability of the seedlings to produce which of the following monomers?
The amino acid in Figure 1 is found in a region of a polypeptide that folds away from water. Which part of the amino acid most likely contributes to the hydrophobic behavior of this region of the polypeptide?
Methyl (CH3) group
Researchers claimed that a particular organelle originated from a free-living prokaryotic cell that was engulfed by a larger cell, as shown in Figure 1.
Which of the following provides evidence to best support the researchers' claim?
The organelle has a double membrane.
The manner in which several different ions and molecules move through a cell membrane is shown in the diagram above. For each ion or molecule, the relative concentration on each side of the membrane is indicated. Which of the following accurately describes one of the movements taking place?
Glucose is transported into the cell by active transport.
A scientist designed an experiment to test an artificial membrane that mimics the phospholipid bilayer of a cell.
The scientist built a tube that was divided by an artificial membrane and filled with distilled water. The scientist put a known amount of a protein into the water on one side of the membrane. After some time, the scientist measured the concentration of the protein on either side of the membrane but found that there had been no change.
Which of the following experimental changes would allow the scientist to observe transport of a solute across the artificial membrane?
Use a small, nonpolar solute instead of a protein
The diagram above represents a typical rod-shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to archaea and bacteria?
The organism does not have a nuclear membrane surrounding its genetic material.
Which one of the following cells is likely to be the most efficient at eliminating waste by diffusion?
Which of the following describes the most likely location of cholesterol in an animal cell?
Embedded in the plasma membrane
Carbon dioxide most likely enters a cell through which of the following processes?
Simple diffusion through the membrane
Which of the following is evidence that eukaryotes and prokaryotes share a common ancestor?
All eukaryotes and prokaryotes contain ribosomes.
Based on Table 1, which of the following best explains the difference in water potential between certain solutions and the grapes?
Grape soda and NaCl have a lower water potential because these two solutions caused the grape to lose water.
Which of the following statements best describes how a growth factor stimulates cell division from outside a cell?
The growth factor binds to receptors on the cell surface, initiating a signal transduction pathway that activates specific target genes.
The mechanism of action of many common medications involves interfering with the normal pathways that cells use to respond to hormone signals. Which of the following best describes a drug interaction that directly interferes with a signal transduction pathway?
A medication enters the target cell and inhibits an enzyme that normally synthesizes a second messenger.
Which of the following accurately describes a model of active transport?
A membrane protein binds a specific molecule outside of the cell and moves the molecule into the cell where there is already a high concentration of the molecule compared with the outside.
Which of the following best describes the numbered areas?
Areas 1 and 3 are polar, since the membrane molecules are aligned with water molecules.
A sample of human blood was placed in a test tube containing a physiological saline solution (0.9% sodium chloride). This type of solution is often used intravenously to quickly rehydrate patients. A drop of the blood from the test tube was placed on a slide and red blood cells (RBCs) were observed under a microscope. Three possible outcomes are diagrammed below.
Which of the following best predicts which diagrammed microscope view the laboratory worker would see and best explains why?
View 2 because the rate of water movement into the RBCs equals the rate of water movement out of the cells
Which of the following best represents two different signaling pathways that share a second messenger?
Water is transported from the soil into the roots of a plant, and then up the stem to the leaves. A student determines that the water potential of root cells in the plant is -0.2 MPa. Which of the following claims is best supported by this measurement?
The water potential of the soil will be higher than -0.2 MPa, whereas the water potential of the leaf will be lower than -0.2 MPa.
A student formulated a hypothesis that water-soluble pollutants damage living organisms by increasing the permeability of cellular membranes. To test the hypothesis, the student investigated the effect of isopropanol and acetone on beet root cells. The vacuoles of beet root cells contain large amounts of betacyanin, a water-soluble pigment that is released into the extracellular environment as a result of increased membrane permeability.
The student prepared identical samples of beet root tissue and incubated each sample for 15 minutes in the specific solution for that group. At the end of the incubation period, the student measured the absorbance of 460 nm light for each sample. A greater concentration of betacyanin in the solution surrounding the beet root cells results in a greater absorbance of 460 nm light. The results of the experiment are shown in the table above.
Which of the following is the dependent variable in the experiment?
The absorbance of 460 nm light by the treatment solutions
The illustration above is a model of a typical beet root cell. Based on the experimental results, which of the following best represents the effect of acetone on the permeability of cellular membranes?
The illustration shows the active transport of hydrogen ions through a membrane protein.
Which of the following best predicts the effect of not having ATP available to supply energy to this process?
H+ ions will stop moving through the protein.
Which of the following best describes the data in Figure 1 ?
At a concentration above 10 p.M, drug X reduces melanoma cell survival.
Pyruvate dehydrogenase is an enzyme that converts pyruvate to acetyl-CoA. Acetyl-CoA is further metabolized in the Krebs cycle. A researcher measured the accumulation of acetyl-CoA in a reaction containing pyruvate and pyruvate dehydrogenase under several different conditions (Figure 1)
The maximum production rate of acetyl-CoA under condition 1 is closest to which of the following?
1 micromole/sec
A researcher claims that increased atmospheric carbon dioxide levels cause increased growth rates in plants.
Which of the following statements best supports the researcher's claim?
Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.
Based on the data in Table 1, which of the following is the earliest time point at which there is a statistical difference in average pH between the control and treatment groups?
20 minutes
Which of the following best describes the process by which the bacteria are breaking down the glucose to produce lactic acid?
The bacteria are breaking down sugars in the absence of oxygen.
Which of the following graphs best represents the data in Table 1?
Which of the following statements about the rate of CO, fixation in the two types of plants is supported by the data shown in the figures?
At 21% O2, plant type 2 has a lower rate of CO2 fixation than plant type 1 does in both types of soil.
Based on Figure 1, the net number of ATP molecules produced during glycolysis from the metabolism of a single glucose molecule is close to which of the following?
2
In an experiment, a scientist isolates mitochondria from living cells and suspends them in two different buffered solutions. One solution is maintained at pH 4, while the other solution is maintained at pH 9. The scientist finds that mitochondria in the solution at pH 4 continue to produce ATP but those in the pH 9 solution do not.
The results of the experiment can be used as evidence in support of which of the following scientific claims about mitochondrial activity?
ATP production in mitochondria requires a hydrogen ion gradient that favors movement of protons into the mitochondrial matrix
Which of the following questions will best direct an investigation of the mechanism of ATP synthase?
Is the phosphorylation of ADP by ATP synthase dependent on the formation of a proton gradient?
Which of the following describes a metabolic consequence of a shortage of oxygen in muscle cells?
A buildup of lactic acid in the muscle tissue due to fermentation
The figure above shows an organelle typically found in eukaryotic cells. Which of the following best describes the function of the double membrane system of this organelle?
The inner membrane has specialized proteins that create a hydrogen ion concentration gradient between the intermembrane space and the matrix.
A scientist claims that Elysia chlorotica, a species of sea slug, is capable of photosynthesis.
Which of the following observations provides the best evidence to support the claim?
Elysia chlorotica grows when exposed to light in the absence of other food sources.
Which of the following best describes the role of ATP and NADPH in the process of photosynthesis?
ATP and NADPH are carriers of chemical energy that is used in the production of carbohydrates.
A researcher is investigating the effects of a chemical that makes thylakoid membranes permeable to hydrogen ions (H+). Which of the following is the most likely direct effect of adding the chemical to plant cells?
The chloroplasts will generate less ATP.
Which of the following best describes the role of water in photosynthesis?
Water molecules donate electrons to the electron transport chain.
A researcher claims that the synthesis of ATP from ADP and inorganic phosphate (Pi) is essential to cellular function.
Which of the following statements best helps justify the researcher's claim?
ATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy.
Based on the information presented, which of the following best explains why the researchers measured oxygen consumption as an indicator of the effectiveness of drug X?
Oxygen accepts electrons in oxidative phosphorylation, a process necessary for melanoma cell survival.
According to the results of this experiment, germination of tobacco seeds during the first week is
Increased by exposure to light
Which of the following correctly uses the data to justify the claim that the phosphagen system is an immediate, short-term source of ATP for muscle cells?
ATP production by the phosphagen system increases and decreases rapidly following the start of the exercise period
Which of the following best explains the connection between energy, growth, and the maintenance of an ordered system in the experiment?
Energy input from light is required for the grass to grow and maintain an ordered structure.
Which of the following best describes the cellular process illustrated in Figure 1 ?
Reducing the chromosome number during anaphase I of meiosis
Within a forest ecosystem, there is a large amount of diversity among members of a warbler species. Of the following stages of meiosis illustrated for a typical cell, which contributes most to diversity among the warblers?
Which of the following best describes how the amount of DNA in the cell changes during M phase?
The amount of DNA is halved as the cell divides into two daughter cells.
Cancer can result from a variety of different mutational events. Which of the following is LEAST likely to result in the initiation of a cancerous tumor?
A defect in a cell-cycle checkpoint prevents a cell from entering the S phase.
Which of the following patterns is shown by the data?
In mutant 3 cells, more time is spent in prophase/prometaphase than in the later stages of mitosis.
What is the expected percent change in the DNA content of a typical eukaryotic cell as it progresses through the cell cycle from the start of the G1 phase to the end of the G2 phase?
+100%
The diploid number of chromosomes in the cell of a domesticated dog is 78. Which of the following options includes the correct number of chromosomes in a cell after each cellular process (G2 checkpoint, meiosis, and fertilization, respectively)?
During prophase I replicated homologous chromosomes pair up and undergo synapsis. What testable question generated regarding synopsis and genetic variability by Figure 1?
Is the distance between two gene loci related to crossover rate?
Which of the following statements correctly describes the chromosomes in each daughter cell at the end of meiosis?
Each daughter cell contains 12 chromosomes, each composed of two chromatids. Each chromosome is one of a pair of homologous chromosomes from the parent cell, with the other homologue found in the other daughter cell.
Both mitosis and meiosis begin with a parent cell that is diploid. Which of the following best describes how mitosis and meiosis result in daughter cells with different numbers of chromosomes?
Mitosis produces two identical diploid daughter cells after one round of division. Meiosis produces four haploid daughter cells after two rounds of division.
Cancer cells behave differently than normal body cells. For example, they ignore signals that tell them to stop dividing?
The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins.
Which of the following describes a mutation that would lead to an increase in the frequency of nondisjunction?
A mutation affecting checkpoint 3 proteins that prevents attachment of spindle fibers
Based on Figure 1, what percent of the time required to complete a full cycle do the cells typically spend in interphase?
95%
Which of the following best explains why triploid bananas do not produce seeds?
The production of gametes is disrupted because of unequal pairing of homologous chromosomes during meiosis.
Scientists have found that DNA methylation suppresses crossing-over in the fungus Ascobolus immersus. Which of the following questions is most appropriately raised by this specific observation?
Is the level of genetic variation in the gametes related to the amount of DNA methylation observed?
Glycogen synthetase kinase 3 beta is a protein kinase that has been implicated in many tass on cancer. Depending on the cell type, the gene for glycogen synthetase kinase 3 beta (GS K 3ß) can act either as an oncogene or as a
tumor suppressor.
Which of the following best predicts how GS K 3ß mutations can lead to the development of cancer?
Cells with inactive GSK 3ß fail to trigger apoptosis.
Which of the following best describes the role of mitosis in the cell cycle?
Distributing replicated chromosomes to daughter nuclei
Saccharomyces cerevisiae is a diploid yeast species that can reproduce either sexually or asexually. An experiment was performed to induce mitotically dividing S. cerevisiae cells in G2 to undergo meiosis. Which of the following best describes the steps these cells will follow to form gametes?
The first division will reduce the number of chromosomes by half for each daughter cell, and the second division will move single chromatids to each daughter cell.
The cell cycle of yeast cells grown in the nutrient-poor environment is approximately what percent of the cell cycle of yeast cells grown in the nutrient rich environment?
168
Researchers studying cell cycle regulation in budding yeast have observed that a mutation in the CDC15 gene causes cell cycle arrest in telophase when the yeast cells are incubated at an elevated temperature. Which of the following statements best predicts the effect of the cell cycle arrest on proliferating yeast cells?
The yeast cells will replicate their chromosomes but will fail to complete cytokinesis.
A blue-flowered African violet of unknown ancestry self-pollinated and produced 50 seeds. These seeds germinate and grow into flowering plants. Of these plants, 36 produce blue flowers and 14 produce pink flowers. What is the best explanation for the pink-flowered offspring?
Pink flower color is a trait recessive to blue flower color.
A gene that influences coat color in domestic cats is located on the X
chromosome. A female cat that is heterozygous for the gene (XBXO) has a calico-colored coat. In a genetics experiment, researchers mate a calico-colored female cat (XBXO) with an orange-colored male cat (XOY) to produce an F1 generation. The researchers record observations for the cats in the F1 generation and plan to use the data to perform a chi-square goodness-of-fit test for a model of X-linked inheritance. The data for the chi-square goodness-of-fit test are presented in Table 1.
The researchers calculate a chi-square value of 4.6 and choose a significance level of p=0.05. Which of the following statements best completes the chi-square goodness-of-fit test?
The null hypothesis cannot be rejected because the chi-squared value is less than the critical value
In pea plants, flower color and the length of the flower's pollen grains are genetically determined. Researchers studying pea plants crossed homozygous dominant pea plants with homozygous recessive pea plants. The F1 plants were then crossed, and the number of offspring with each phenotype was recorded. The researchers' observed data, however, differed from the expected data. The researchers did a chi-square analysis and calculated the chi-square value to be 5.5.
Based on their calculation, the researchers would most likely conclude which of the following?
The differences between observed data and expected data are due to chance.
In a certain type of chicken, the allele for gray feathers is recessive to the allele for black feathers, and the allele for a spotted pattern is recessive to the allele for a solid pattern. Chickens that are heterozygous for both traits were crossed and the phenotypes for the offspring were recorded (Table 1).
To determine whether the data are consistent with the expectations for independent assortment, students performed a chi-square analysis.
Which of the following is the closest to the calculated chi-square value for the experiment?
0.95
In fruit flies of the genus Drosophila, the allele for vestigial wings is recessive to the allele for round wings, and the allele for brown eye color is recessive to the allele for red eye color. A scientist crossed flies that are heterozygous for both traits and determined the number of offspring with each combination of phenotypes. The scientist performed a chi-square analysis to determine if the data are consistent with the expectations for independent assortment. The chi-square calculated value for the experiment was 6.03.
Based on the chi-square calculated value, which of the following statements is most accurate?
The chi-square calculated value is less than the chi-square critical value, therefore the null hypothesis should not be rejected.
Eye color in a particular strain of fly is influenced by one gene with two alleles: a dominant allele that results in red eyes and a recessive allele that results in sepia eyes.
A red-eyed female from a true-breeding population is mated with a sepia-eyed male. The Fl offspring are all red-eyed. The F1 flies are allowed to interbreed, producing the following in the F2 generation.
Females: 40 red eyes; 13 sepia eyes
Males: 39 red eyes; 11 sepia eyes
Which of the following best describes the likely mode of inheritance for the eye-color gene?
The eye-color gene is likely autosomal because males and females have similar phenotype ratios.
A genetic counselor is consulted by a young man who is worried about developing Huntington's disease, an inherited disorder caused by a dominant allele of a single gene. The young man explains that his cousin was recently diagnosed with Huntington's disease, and the news has caused him to consider his own risk of developing the disorder. Which of the following questions will best help the genetic counselor to evaluate the risk of the young man developing Huntington's disease and transmitting it to his children?
Were your parents or grandparents ever diagnosed with Huntington's disease?
Hydrangea flowers differ in color based on interactions between a pigment in the flower cells and aluminum ions dissolved in water absorbed from the soil. When aluminum ions are present, the pigment is blue; when aluminum ions are absent, the pigment is pink. The amount of aluminum ions the plant can absorb is dependent on the pH of the soil.
Which of the following questions will best help a researcher design an experiment to learn about the relationship between hydrangea flower color, aluminum, and pH?
What will be the flower color of hydrangeas grown in soils pf varying pH with or without aluminum?
In pea seeds, yellow color (Y) is dominant to green color (y), and a round shape (r) is dominant to a wrinkled shape (r). A dihybrid cross between a true-breeding plant with yellow, round seeds (YY RR) and a true-breeding pant with green, wrinkled seeds (yyrr) results in an F1 generation of plants with yellow, round seeds. Crossing two F1 plants produces an F2 generation with approximately nine times as many plants with yellow, round seeds as plants with green, wrinkled seeds.
Which of the following best explains these results?
The genes for seed color and seed shape assort independently
The diagram Depicts a karyotype
Which of the following statements concerning the karyotype in the diagram is true?
The diagram illustrates the results of nondisjunction during gamete formation.
If the normal spermatogenesis is disrupted, the gametes can have different chromosomes than expected. Which the following is the most likely cause of one of the four gametes having two X chromosomes and one having neither an X nor a Y chromosome?
Nondisjunction of the X chromosome during meiosis II
which of the following best explains the observed pattern of inheritance?
The trait is autosomal recessive, because the cross between individuals I-1 and I-2 produced an affected offspring.
Pigeons demonstrate ZW sex determination, such that a ZZ genotype produces a male and a ZW genotype produces a female. The gene for feather color is located on the Z chromosome, and the red allele is dominant over the brown allele. Three crosses between brown male pigeons and red female pigeons were performed, and the results are shown below.
Which of the following is the mean number of male offspring produced by the three crosses?
9
A researcher is crossing two organisms that are heterozygous for three Mendelian, unlinked traits (XxYyZz).
Which of the following is the fraction of offspring that are predicted to have the genotype xxyyzz?
1/64
Tay-Sachs disease is a rare inherited disorder caused by an autosomal recessive allele of the HEXA gene. Affected individuals exhibit severe neurological symptoms and do not survive to reproductive age. Individuals who inherit one copy of the allele (Tay-Sachs carriers) typically show no symptoms of the disorder. The frequencies of Tay-Sachs carriers in the general population of North America and in three different subpopulations are presented in the table.
Which of the following pedigrees most accurately represents a family with a history of Tay-Sachs disease?
An African violet grower observes that genetically identical African violet plants growing near the walls of the greenhouse have white flowers, that plants growing farther away from the walls have pale blue flowers, and that plants growing nearest the center of the greenhouse have dark blue flowers.
Which of the following best explains the differences in flower color of the African violets in the greenhouse?
An enzyme responsible for flower color does not fold correctly in cooler temperatures, and the greenhouse is warmest in the center.
Based on the data in Figure 1, which of the following best describes the inheritance pattern of Friedreich's ataxia?
Autosomal recessive
The probability that individual III-5 will develop Friedreich's ataxia is closest to which of the following?
25%
Red-green color blindness in humans is caused by a recessive allele located on the X chromosome. Figure 1 shows the potential offspring of a female who is red-green color-blind and a male with full-color vision. All of the possible male offspring would be color-blind, and all of the possible female offspring would have full-color vision.
If during the production of male gametes an error in meiosis occurred, sperm containing both an X and a Y chromosome could be produced.
How would the extra chromosome affect the male offspring produced by the gamete?
The male offspring would have full-color vision, because of the presence of the extra X chromosome.
A researcher hypothesizes that, in mice, two autosomal dominant traits, trait Q and trait R, are determined by separate genes found on the same chromosome. The researcher crosses mice that are heterozygous for both traits and counts the number of offspring with each combination of phenotypes. The total number of offspring produced was 64. The researcher plans to do a chi-square analysis of the data and calculates the expected number of mice with each combination of phenotypes. Which of the following is the expected number of offspring that will display both trait Q and trait R?
36
