In 1908, a huge explosion known as the Tunguska Event flattened trees for miles across a remote area of Russia. Scientists now think an asteroid or a comet entered Earth's atmosphere, causing the explosion. Ice core samples from an ice sheet in Greenland reveal signs of this enormous explosion: deposits of ammonia equal to 5 micrograms per square meter. But how exactly did these telltale molecules form?
• Hypothesis 1: The Tunguska explosion started forest fires, known to produce ammonia. Data indicates that such fires would have deposited an amount of ammonia over the Northern Hemisphere equaling 0.1 micrograms per square meter.
• Hypothesis 2: Up to 1% of the object's mass might have been ammonia, and this ammonia might have spread over the Northern Hemisphere. Approximately 0.00005 micrograms of ammonia per square meter are predicted by this hypothesis.
• Hypothesis 3: Since many compounds form in the presence of high heat, the ammonia could
have been produced as the falling object heated the atmosphere. However, heat alone is not
sufficient to cause the formation of ammonia.
• Hypothesis 4: As it passed through the atmosphere, the object pushed air in front of it at high pressure. Nitrogen and hydrogen combine to form ammonia under similar pressure. Considering the amount of hydrogen expected in a comet and the available nitrogen in Earth's atmosphere, approximately 5 micrograms of ammonia per square meter would have been deposited under this hypothesis.
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.
Other Related Questions
Sommer's research concludes that cheetahs have sufficient genetic diversity to respond to common diseases, but may still be at risk of new diseases. Which statement from the passage supports this conclusion?
- A. Major histocompatibility complex (MHC) genes are used by the body to identify self from non-self...
- B. The variation in MHC genes in cheetahs is still smaller than that for other big cat species but appears to be sufficient...
- C. If any of the genetic factors are different, then the immune system of the individual...
- D. Sommer's research determined how many alleles are present on two different types of MHC genes...
Correct Answer & Rationale
Correct Answer: B
Option B directly supports Sommer's conclusion by highlighting that the variation in MHC genes among cheetahs, while less than in other big cats, is adequate for their immune response to common diseases. This indicates sufficient genetic diversity for disease management, aligning with the research's findings. Option A discusses the function of MHC genes but does not address their variation in cheetahs, making it less relevant. Option C mentions genetic factors affecting immune response but lacks specific information about cheetah genetic diversity. Option D focuses on the number of alleles without linking it to the implications for disease response, thus failing to support the conclusion effectively.
Option B directly supports Sommer's conclusion by highlighting that the variation in MHC genes among cheetahs, while less than in other big cats, is adequate for their immune response to common diseases. This indicates sufficient genetic diversity for disease management, aligning with the research's findings. Option A discusses the function of MHC genes but does not address their variation in cheetahs, making it less relevant. Option C mentions genetic factors affecting immune response but lacks specific information about cheetah genetic diversity. Option D focuses on the number of alleles without linking it to the implications for disease response, thus failing to support the conclusion effectively.
Which statement explains the central idea of the passage?
- A. People should consume as much magnesium as possible to ensure good cardiovascular health.
- B. People may experience health benefits from drinking hard water because it contains magnesium.
- C. People who live in rural environments are healthier than people who live in urban environments.
- D. People should stop the practice of softening water because it removes minerals that are necessary for good health.
Correct Answer & Rationale
Correct Answer: B
Option B accurately reflects the central idea by highlighting the potential health benefits of magnesium found in hard water. This aligns with the passage's focus on the relationship between magnesium intake and cardiovascular health. Option A is misleading as it suggests an excessive intake of magnesium is necessary, while the passage likely emphasizes balance rather than maximum consumption. Option C incorrectly generalizes health comparisons between rural and urban populations without specific evidence from the passage. Option D misrepresents the passage's message by implying a complete cessation of water softening, rather than discussing the importance of maintaining essential minerals like magnesium.
Option B accurately reflects the central idea by highlighting the potential health benefits of magnesium found in hard water. This aligns with the passage's focus on the relationship between magnesium intake and cardiovascular health. Option A is misleading as it suggests an excessive intake of magnesium is necessary, while the passage likely emphasizes balance rather than maximum consumption. Option C incorrectly generalizes health comparisons between rural and urban populations without specific evidence from the passage. Option D misrepresents the passage's message by implying a complete cessation of water softening, rather than discussing the importance of maintaining essential minerals like magnesium.
According to the passage, which statement about hybrid lovebirds is true?
- A. Nest-building behavior can be used to determine evolutionary relationships between lovebird species.
- B. Hybrid lovebirds use nest-building material in ways they learn from the parents.
- C. Nest-building behavior in hybrid lovebirds is a mixture of the parents' behaviors.
- D. Hybrid lovebirds build complex nests using smaller pieces of nest-building material.
Correct Answer & Rationale
Correct Answer: C
Hybrid lovebirds exhibit nest-building behavior that reflects a combination of their parents' distinct styles, showcasing the influence of both species in their hybrid traits. This blending of behaviors illustrates how hybridization can lead to unique adaptations. Option A is incorrect as the passage does not indicate that nest-building behavior is a reliable indicator of evolutionary relationships. Option B is misleading; while learning from parents is important, the focus is on the integration of behaviors rather than direct imitation. Option D is inaccurate; the passage does not mention the complexity of nests or the size of materials used, making this statement unsupported.
Hybrid lovebirds exhibit nest-building behavior that reflects a combination of their parents' distinct styles, showcasing the influence of both species in their hybrid traits. This blending of behaviors illustrates how hybridization can lead to unique adaptations. Option A is incorrect as the passage does not indicate that nest-building behavior is a reliable indicator of evolutionary relationships. Option B is misleading; while learning from parents is important, the focus is on the integration of behaviors rather than direct imitation. Option D is inaccurate; the passage does not mention the complexity of nests or the size of materials used, making this statement unsupported.
What natural process is required to connect the ice core data to the Tunguska Event?
- A. the cycling of carbon in forest fires
- B. the interaction of comets with the solar wind
- C. the movement of glaciers due to gravity
- D. the constant mixing of the atmosphere
Correct Answer & Rationale
Correct Answer: D
Connecting ice core data to the Tunguska Event necessitates understanding atmospheric dynamics, which is achieved through the constant mixing of the atmosphere. This mixing disperses particles and gases, allowing researchers to correlate ice core samples with historical events, including the Tunguska explosion. Option A, the cycling of carbon in forest fires, is unrelated to the atmospheric conditions or the specific data derived from ice cores. Option B, the interaction of comets with the solar wind, pertains to space phenomena rather than terrestrial atmospheric processes. Option C, the movement of glaciers due to gravity, describes glacial dynamics but does not address the atmospheric mixing needed to link ice core data to the event.
Connecting ice core data to the Tunguska Event necessitates understanding atmospheric dynamics, which is achieved through the constant mixing of the atmosphere. This mixing disperses particles and gases, allowing researchers to correlate ice core samples with historical events, including the Tunguska explosion. Option A, the cycling of carbon in forest fires, is unrelated to the atmospheric conditions or the specific data derived from ice cores. Option B, the interaction of comets with the solar wind, pertains to space phenomena rather than terrestrial atmospheric processes. Option C, the movement of glaciers due to gravity, describes glacial dynamics but does not address the atmospheric mixing needed to link ice core data to the event.