The cladogram shows the relatedness of several organisms based on shared characteristics. Which characteristic separates catfish from frogs?
- A. Suborbital fenestra
- B. Amniotic egg
- C. Four limbs
- D. Bony skeleton
Correct Answer & Rationale
Correct Answer: B
The presence of an amniotic egg is a key characteristic that distinguishes frogs from catfish. Frogs, as amphibians, undergo a life cycle that includes an aquatic larval stage, while catfish, as fish, do not produce amniotic eggs and instead lay eggs in water. Option A, suborbital fenestra, relates to skull structure and is not a defining characteristic that separates these groups. Option C, four limbs, applies to frogs but not to catfish, which possess fins instead. Option D, bony skeleton, is present in both groups, making it an insufficient distinguishing trait.
The presence of an amniotic egg is a key characteristic that distinguishes frogs from catfish. Frogs, as amphibians, undergo a life cycle that includes an aquatic larval stage, while catfish, as fish, do not produce amniotic eggs and instead lay eggs in water. Option A, suborbital fenestra, relates to skull structure and is not a defining characteristic that separates these groups. Option C, four limbs, applies to frogs but not to catfish, which possess fins instead. Option D, bony skeleton, is present in both groups, making it an insufficient distinguishing trait.
Other Related Questions
Scientists have estimated the mass of the object that caused the Tunguska Event at 5 x 10^12 kilograms (kg). If the object was a comet in which 1% of total mass was ammonia, how much ammonia did the comet contain? kg
Correct Answer & Rationale
Correct Answer: 5x10^10
To find the mass of ammonia in the comet, we calculate 1% of the total mass (5 x 10^12 kg). This is done by multiplying the total mass by 0.01: 5 x 10^12 kg × 0.01 = 5 x 10^10 kg. This calculation confirms that the comet contained 5 x 10^10 kg of ammonia. Other options may result from incorrect calculations, such as misunderstanding the percentage or misapplying the multiplication. For instance, using 0.1 instead of 0.01 would yield an answer ten times larger, while failing to convert the percentage to a decimal would also lead to an incorrect figure.
To find the mass of ammonia in the comet, we calculate 1% of the total mass (5 x 10^12 kg). This is done by multiplying the total mass by 0.01: 5 x 10^12 kg × 0.01 = 5 x 10^10 kg. This calculation confirms that the comet contained 5 x 10^10 kg of ammonia. Other options may result from incorrect calculations, such as misunderstanding the percentage or misapplying the multiplication. For instance, using 0.1 instead of 0.01 would yield an answer ten times larger, while failing to convert the percentage to a decimal would also lead to an incorrect figure.
The graph shows results from a study that sought to determine average exposure to triclosan in the U.S. population. Which statement is supported by the results in the graph?
- A. Triclosan concentration does not vary significantly among different age groups.
- B. Increased levels of triclosan in urine are related to increased age.
- C. Triclosan concentration in urine is highest in the 30- to 39-year-old age group.
- D. People aged 20-29 likely use more products containing triclosan.
Correct Answer & Rationale
Correct Answer: C
The data indicates that the highest triclosan concentration in urine occurs in the 30- to 39-year-old age group, supporting option C. This finding highlights a specific peak in exposure among this demographic. Option A is incorrect as the graph likely shows variation in triclosan levels across age groups. Option B misinterprets the data; the graph does not suggest that triclosan levels increase with age. Option D assumes usage patterns without evidence from the graph, which focuses on urinary concentration rather than product usage.
The data indicates that the highest triclosan concentration in urine occurs in the 30- to 39-year-old age group, supporting option C. This finding highlights a specific peak in exposure among this demographic. Option A is incorrect as the graph likely shows variation in triclosan levels across age groups. Option B misinterprets the data; the graph does not suggest that triclosan levels increase with age. Option D assumes usage patterns without evidence from the graph, which focuses on urinary concentration rather than product usage.
Scientists are Interested in whether certain greenhouse gases have helped cause I recent temperature increases. The graph presents data on carbon dioxide and methane gas levels in the atmosphere for the past several centuries. Human activities began producing large quantities of both gases in the 1700s. This graph, combined with information from--------------------, supports ----------------------.
- A. The Milankovitch climate change model
- B. paragraph 3
- C. The anthropogenic climate change model
- D. Paragraph 2
Correct Answer & Rationale
Correct Answer: B, C
The graph illustrates the correlation between rising greenhouse gas levels and temperature increases, supporting the anthropogenic climate change model, which attributes climate change to human activities. Options B and C effectively connect the visual data with the broader context of human influence on climate. Option A, referencing the Milankovitch model, is incorrect as this model focuses on natural Earth cycles, not human impact. Option D lacks specificity and does not directly relate to the evidence presented in the graph. Thus, B and C provide the most relevant support for understanding the relationship between greenhouse gas emissions and climate change.
The graph illustrates the correlation between rising greenhouse gas levels and temperature increases, supporting the anthropogenic climate change model, which attributes climate change to human activities. Options B and C effectively connect the visual data with the broader context of human influence on climate. Option A, referencing the Milankovitch model, is incorrect as this model focuses on natural Earth cycles, not human impact. Option D lacks specificity and does not directly relate to the evidence presented in the graph. Thus, B and C provide the most relevant support for understanding the relationship between greenhouse gas emissions and climate change.
What statement describes one or more needed changes to this experiment that would allow the experimenter to draw a valid conclusion?
- A. Salt water should have been used to make the ice cubes for the cup of salt water.
- B. The time for ice cubes to melt should have been measured in minutes.
- C. At the beginning, both cups should have contained the same mass of water at the same temperature.
- D. The energy released should have been measured, not calculated.
Correct Answer & Rationale
Correct Answer: C
Option C highlights the necessity for both cups to start with the same mass of water at the same temperature to ensure a fair comparison. This control eliminates variables that could skew results, allowing for a valid conclusion about the melting rates of ice cubes in different solutions. Option A is incorrect because using salt water to make ice cubes would not provide relevant data on how the ice behaves in fresh versus salt water. Option B is not a change that affects the experimental validity; measuring time in minutes is appropriate, but the key is ensuring conditions are equal. Option D suggests a measurement method change, but calculating energy based on temperature changes is acceptable in this context.
Option C highlights the necessity for both cups to start with the same mass of water at the same temperature to ensure a fair comparison. This control eliminates variables that could skew results, allowing for a valid conclusion about the melting rates of ice cubes in different solutions. Option A is incorrect because using salt water to make ice cubes would not provide relevant data on how the ice behaves in fresh versus salt water. Option B is not a change that affects the experimental validity; measuring time in minutes is appropriate, but the key is ensuring conditions are equal. Option D suggests a measurement method change, but calculating energy based on temperature changes is acceptable in this context.