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Example Questions
Example Question #204 : How To Find Synthesis Of Data In Biology
The mountain chickadee is a bird native to Colorado’s coniferous forests, preferring to live in areas 6,000 to 12,000 feet in elevation. They are a resident species, meaning they do not migrate south for the winter.
The mountain chickadee nests in coniferous trees, caves, snags and abandoned foxholes and eats insects, berries, and seeds. They tend to stay close to the breeding ground for most of their adult lives, and do not care for treeless valleys outside of the high country.
Researchers wish to know more about the nesting behaviors of these animals. For a calendar year, these researchers documented nesting patterns of the male chickadees in a coniferous forest in Northern Colorado. The researchers took note of both the season as well as the characteristics of the chickadee nests in order to establish a pattern. The results are documented below.
Mountain Chickadee Nesting and Survival Patterns June 2011- May 2012:
|
Summer |
Fall |
Winter |
Spring |
|
|
Location within Forest |
Coniferous tree branch |
Woodpecker hole |
Abandoned foxhole |
Coniferous tree cavity |
|
Average Time to Build Nest |
6 hrs |
8 hrs |
12 hrs |
8 hrs |
|
Average Duration of Stay |
8 weeks |
6 weeks |
4 weeks |
6 weeks |
|
Average Number of Offspring |
2 |
1 |
0 |
3 |
|
Average Death Rate of Bird |
1:15 |
1:12 |
1:8 |
1:12 |
If the Spring begins with 12 chickadees, what could be a reasonable number of chickadees at the end of the Spring, considering three are female.
21
20
11
18
20
There will be, on average, 20 Chickadees at the end of the Spring if we began the season with twelve. If three are female, we can assume they each had, on average, three offspring.
But remember that, on average, one of those original twelve will die sometime during the season. Thus, we can reasonably assume there will be 20 birds left.
Example Question #491 : Biology
Botulism is a rare disease caused by the botulinum toxin produced and secreted by Clostridium botulinum. Botulism causes muscle weakness and in severe cases can inhibit the muscles of respiration and lead to respiratory failure and even death. The exotoxin produced by Clostridium botulinum causes damage to its host by inhibiting of the release of the chemical messenger acetylcholine. Acetylcholine is a neurotransmitter, meaning it is responsible for enabling communication between a nerve cell and other cells.
Experiment A
Scientists conducting a study on the lethality of the botulinum toxin are looking at the effect of acidification on the toxin’s potency. They design a study in mice to identify the minimal lethal dose of botulinum toxin. The scientists believe acidification will reduce the minimal lethal dose. The findings from their study are below:
Experiment B
Scientists also assessed the relationship between acidification and the incubation period. The incubation period was defined as the time between exposure to the toxin and the onset of symptoms.
Data and concepts from: Bronfenbrenner, J. & Schlesinger M.J. (1922). Some of the factors contributing to toxicity of botulinus toxin by mouth. JAMA, 78(20), 1519-1521.
What minimal lethal dose would you expect for a pH of 9.0?
Example Question #492 : Act Science
Botulism is a rare disease caused by the botulinum toxin produced and secreted by Clostridium botulinum. Botulism causes muscle weakness and in severe cases can inhibit the muscles of respiration and lead to respiratory failure and even death. The exotoxin produced by Clostridium botulinum causes damage to its host by inhibiting of the release of the chemical messenger acetylcholine. Acetylcholine is a neurotransmitter, meaning it is responsible for enabling communication between a nerve cell and other cells.
Experiment A
Scientists conducting a study on the lethality of the botulinum toxin are looking at the effect of acidification on the toxin’s potency. They design a study in mice to identify the minimal lethal dose of botulinum toxin. The scientists believe acidification will reduce the minimal lethal dose. The findings from their study are below:
Experiment B
Scientists also assessed the relationship between acidification and the incubation period. The incubation period was defined as the time between exposure to the toxin and the onset of symptoms.
Data and concepts from: Bronfenbrenner, J. & Schlesinger M.J. (1922). Some of the factors contributing to toxicity of botulinus toxin by mouth. JAMA, 78(20), 1519-1521.
Given that exposure to botulinum toxin usually occurs through food and the stomach is an acidic environment, which of the following is a reasonable conclusion based on the evidence from this experiment?
The acidic environment will contribute to the potency of the toxin.
The potency will be reduced through the toxin creating a more basic environment.
The stomach acid will destroy the toxin.
The toxin’s introduction to an acidic environment will lead to more dilution of the toxin.
The acidic environment will contribute to the potency of the toxin.
Our chart demonstrates that with increased acidification (a lower pH) there is a decrease in the minimal lethal dose. Thus, the acidic stomach will decrease the minimal lethal dose or in other words increase the potency of our toxin.
Example Question #491 : Biology
Botulism is a rare disease caused by the botulinum toxin produced and secreted by Clostridium botulinum. Botulism causes muscle weakness and in severe cases can inhibit the muscles of respiration and lead to respiratory failure and even death. The exotoxin produced by Clostridium botulinum causes damage to its host by inhibiting of the release of the chemical messenger acetylcholine. Acetylcholine is a neurotransmitter, meaning it is responsible for enabling communication between a nerve cell and other cells.
Experiment A
Scientists conducting a study on the lethality of the botulinum toxin are looking at the effect of acidification on the toxin’s potency. They design a study in mice to identify the minimal lethal dose of botulinum toxin. The scientists believe acidification will reduce the minimal lethal dose. The findings from their study are below:
Experiment B
Scientists also assessed the relationship between acidification and the incubation period. The incubation period was defined as the time between exposure to the toxin and the onset of symptoms.
Data and concepts from: Bronfenbrenner, J. & Schlesinger M.J. (1922). Some of the factors contributing to toxicity of botulinus toxin by mouth. JAMA, 78(20), 1519-1521.
Based on the data obtained from both experiments, what is a reasonable conclusion?
As the pH decreases, there is a longer incubation period and a lower minimal lethal dose.
As the pH increases, there is a shorter incubation period and a lower minimal lethal dose.
As the pH increases, there is a longer incubation period and a lower minimal lethal dose.
As the pH decreases, there is a shorter incubation period and a lower minimal lethal dose.
As the pH increases, there is a shorter incubation period and a lower minimal lethal dose.
As the pH decreases, the minimal lethal dose decreases and the incubation decreases. Thus, the best synthesis of both experiments states these two conclusions.
Example Question #494 : Act Science
The cells of multicellular organisms must be linked to each other through special structures called cellular junctions. A gap junction is a type of cellular junction, which allows for the passage of small molecules for fast coordination between cells. For example, cardiac cells in the heart and neurons in the brain rely on gap junctions. However, gap junctions are small and there is a limit to how large a molecule can be in order for it to pass through the gap junction.
An experiment is designed to see how large molecules can be to pass through a gap junction. A single layer of cells is grown in a petri dish. A single cell is then injected with a dye labeled with a fluorescent molecule. Researchers observe the following:
Gap junctions allow for ultra-fast coordination between cells. Which of the following physiological processes would likely be related to gap junctions?
Gap junctions are a key component of intestinal epithelial cells.
Gap junctions assist erythrocytes also known as red blood cells.
Gap junctions aid the passage of large proteins between epithelial cells.
Gap junctions are critical to the coordinated contraction of the heart.
Gap junctions are critical to the coordinated contraction of the heart.
In the passage, it describes gap junctions as a critical component of cardiac cells. Based on our limited information, it most logical to conclude that gap junctions are critical to the coordinated contraction of the heart.
Example Question #492 : Biology
The cells of multicellular organisms must be linked to each other through special structures called cellular junctions. A gap junction is a type of cellular junction, which allows for the passage of small molecules for fast coordination between cells. For example, cardiac cells in the heart and neurons in the brain rely on gap junctions. However, gap junctions are small and there is a limit to how large a molecule can be in order for it to pass through the gap junction.
An experiment is designed to see how large molecules can be to pass through a gap junction. A single layer of cells is grown in a petri dish. A single cell is then injected with a dye labeled with a fluorescent molecule. Researchers observe the following:
There is evidence that insulin (5808 Daltons) passes from cell to cell. Which of the following is a reasonable statement?
Insulin passes from once cell into another but it is unlikely that this molecule passes through a gap junction due to its size.
Insulin must not pass from one cell into another because it is too large to pass through a gap junction.
If insulin passes from one cell into another cell, it must pass through a gap junction.
The charge of this molecule prevents it from passing through a cellular junction.
Insulin passes from once cell into another but it is unlikely that this molecule passes through a gap junction due to its size.
The size of insulin (5808 Da) means it will not pass thru a gap junction. However, the question notes it passes from cell to cell and the passage notes that a gap junction is one type of a cellular junction. Thus, it is reasonable to conclude that insulin probably uses some other junction to pass to another cell. We are not told anything about the charge of insulin, nor whether this charge will facilitate or hinder its movement between cells via junctions.
Example Question #496 : Act Science
Poisons dart frogs earned their name because of a deadly neurotoxin they produce and secrete. To synthesize this neurotoxin, the frogs must consume termites which contain the necessary precursors that the frog processes into their poison. Frogs consuming more of these termites will be more poisonous than frogs consuming smaller amounts. Previous experiments have also shown that neurotoxin production is highest at low temperatures and decreases as temperatures increase.
A team of researchers is curious about when these frogs are most toxic. They record average monthly temperatures for a year and count the number of termites found within a 5,000 square foot area as a measure of termite density in the environment. Results are shown below.
Between the months of August and December, what best describes the trend in frog toxicity?
Toxicity remains the same
Toxicity increases
Toxicity decreases
Toxicity increases then decreases
Toxicity decreases then increases
Toxicity increases
To find out the trend in frog toxicity, we must look at the two variables affecting toxicity mentioned in the text: termite availability and temperature. Toxicity increases as temperature decreases and increases as termite density increases. During the period between August and December, temperature consistently decreases and termite density consistently increases, yielding an increase in toxicity during that time period.
Example Question #497 : Act Science
Researchers at a biotechnology company have just developed a new immortal line of mammalian cells derived from raccoon hair follicles. They dub these cells RHF and note that they appear particularly resistant to environmental stressors in initial experiments. They design a set of experiments to test the limits of the RHF cell line.
Experiment 1: The scientists inoculate 5 identical flasks containing growth media with samples of the RHF cells. The flasks are then incubated in separate incubators at varying temperatures. The flasks are sampled daily for cell density to analyze growth of the cells, yielding these results:
| Cell Density (million cells per mL) | |||||||
| Day | |||||||
| Temperature | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 32 °C | 0.1 | 0.1 | 0.3 | 0.5 | 0.9 | 1.6 | 2.5 |
| 37 °C | 0.1 | 0.2 | 0.4 | 0.8 | 1.5 | 3.3 | 6.3 |
| 42 °C | 0.1 | 0.2 | 0.4 | 0.7 | 1.3 | 2.2 | 4.1 |
| 47 °C | 0.1 | 0.1 | 0.2 | 0.3 | 0.5 | 0.9 | 1.7 |
| 52 °C | 0.1 | 0 | 0 | 0 | 0 | 0 | 0 |
Experiment 2: The scientists produce 5 separate batches of cell growth media containing various amounts of salt to raise the osmolality of the solution. They inoculate 5 flasks, each with various osmolalities, then incubate the flasks at 37 °C for seven days. The flasks are sampled daily for cell density, yielding these results:
| Cell Density (million cells per mL) | |||||||
| Day | |||||||
| Osmolality (mOsm/kg) | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 310 | 0.1 | 0.2 | 0.4 | 0.8 | 1.5 | 3.3 | 6.3 |
| 340 | 0.1 | 0.2 | 0.3 | 0.7 | 1.4 | 2.8 | 4.9 |
| 380 | 0.1 | 0.2 | 0.3 | 0.6 | 1 | 1.8 | 3.5 |
| 420 | 0.1 | 0.1 | 0.2 | 0.3 | 0.5 | 0.8 | 1.4 |
| 460 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.3 | 0.4 |
Based on the results of this experiment, what is the maximum temperature that RHF cells can survive at?
Cannot be determined.
In experiment 1, cells were able to survive at 
Example Question #498 : Act Science
A sports physician is conducting an experiment in which a competitive bicycle rider has her heart rate, oxygen content in blood, and blood lactate measured. The measurements are taken at resting, during easy, moderate, difficult, and very difficult exercise. The results are summarized in the table below. Please note that the oxygen content was normalized to the resting oxygen content.
How is the level of blood lactate affected by the intensity of the workout?
Blood lactate level decreases as workout intensity increases
Blood lactate level linearly increases with workout intensity
Cannot be determined from the given information
There is no relationship between blood lactate level and workout intensity
Blood lactate level non-linearly increases with workout intensity
Blood lactate level non-linearly increases with workout intensity
At a resting intensity the blood lactate level is 0 mmol and increases to 0.5 mmol at an easy workout. This is an increase of 0.5 mmol. Looking at a difficult workout to the very difficult workout is an increase from 4 mmol to 10 mmol, which is an increase of 6 mmol. There is a pattern of the blood lactate level increasing with workout intensity, but it is not a linear relationship.
Example Question #491 : Biology
A sports physician is conducting an experiment in which a competitive bicycle rider has her heart rate, oxygen content in blood, and blood lactate measured. The measurements are taken at resting, during easy, moderate, difficult, and very difficult exercise. The results are summarized in the table below. Please note that the oxygen content was normalized to the resting oxygen content.
What is the relationship between oxygen content and blood lactate level?
Cannot be determined from the given information
As the oxygen content decreases, the blood lactate level decreases
As the oxygen content increases, the blood lactate level increases
As the oxygen content decreases, the blood lactate level increases
There is no relationship
As the oxygen content decreases, the blood lactate level increases
At an oxygen content of 100%, the blood lactate level is 0 mmol. At an oxygen content of 95%, the blood lactate level is 0.5 mmol. This shows that as the oxygen content decreases, the blood lactate level increases. This relationship can be seen in the rest of the data as well.
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