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Reading
The Role of Pheromones in Insect Communication
life sciencebiology語彙
簡単
Reading
The Role of Pheromones in Insect Communication
life sciencebiology語彙
簡単
Paragraph 1
In the intricate world of insects, communication is a matter of survival, essential for everything from finding food and mates to defending against predators. While humans rely heavily on sight and sound, insects have evolved to use a different, more ancient medium: chemical signaling. The most important of these chemical signals are pheromones, which are substances secreted by an individual that trigger a specific behavioral or physiological response in other members of the same species. This chemical language is remarkably potent; a single molecule of a pheromone can be enough to elicit a reaction from a great distance. It is a silent, invisible world of communication that governs nearly every aspect of an insect's life.
Paragraph 2
Pheromones can be broadly classified into two types based on their function: releaser pheromones and primer pheromones. Releaser pheromones have an immediate, direct effect on the behavior of the recipient. A classic example is the alarm pheromone. When an ant's nest is disturbed, some ants will release an alarm pheromone that quickly spreads, causing other ants in the vicinity to become aggressive and ready to defend the colony. Sex attractant pheromones are another common type of releaser. A female moth, for instance, might release a plume of sex pheromones that males can detect miles away, enabling them to home in on her location for mating. These signals are typically volatile, meaning they evaporate and disperse quickly, and are effective for short-term communication.
Paragraph 3
In contrast, primer pheromones work on a much slower timescale, triggering long-term physiological changes rather than immediate behavioral ones. They are fundamental in regulating the social structure and development of insect colonies. For example, in a honeybee colony, the queen bee constantly produces a special 'queen substance' pheromone. This primer pheromone is passed throughout the hive via contact and food sharing. Its presence inhibits the development of ovaries in the female worker bees, ensuring that the queen remains the sole reproductive individual in the colony. If the queen dies and the pheromone signal disappears, the physiological effect is reversed, and some worker bees will begin to develop ovaries to lay eggs, attempting to produce a new queen.
Paragraph 4
Insects also use trail pheromones to create chemical maps of their environment. Foraging ants, upon discovering a food source, will lay down a trail of pheromones on their journey back to the nest. Other ants can then detect this trail and follow it directly to the food. The strength of the trail can even communicate information about the quality and quantity of the food source; more ants will reinforce the trail if the food is particularly rich, creating a stronger signal that attracts even more foragers. This collective behavior allows the entire colony to efficiently exploit resources that a single ant could not. The trail evaporates over time, so that old, depleted food sources are no longer marked, preventing wasted effort.
Paragraph 5
The specificity of pheromones is one of their most crucial features. Each pheromone is a unique chemical compound, or a specific blend of compounds, that is recognized only by members of the same species. This prevents communication from being intercepted or misunderstood by other species, including predators or competitors. This species-specificity is vital for reproductive isolation, ensuring that insects do not waste time and energy attempting to mate with an incompatible partner. Scientists have harnessed this knowledge in agriculture, developing synthetic pheromone traps that lure specific pest insects, disrupting their mating cycles without the need for broad-spectrum chemical pesticides that can harm beneficial insects.
The word 'potent' in paragraph 1 is closest in meaning to...
The word 'vicinity' in paragraph 2 is closest in meaning to...
According to paragraph 2, what is the main purpose of a sex attractant pheromone?
What happens in a honeybee colony if the queen dies, according to paragraph 3?
What can be inferred about trail pheromones from paragraph 4?
In paragraph 5, why does the author mention the use of synthetic pheromone traps in agriculture?
What does the passage imply about the difference between primer and releaser pheromones?
What is the primary function of the 'queen substance' in a honeybee hive?
Look at the four squares [■] that indicate where the following sentence could be added to paragraph 2. Where would the sentence best fit?
This signal is a call to arms for the whole community.
An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
Pheromones are a vital form of species-specific chemical communication that governs most aspects of insect life.
Select 3 answer choices that express the most important ideas in the passage. This question is worth 2 points.
Paragraph 1
In the intricate world of insects, communication is a matter of survival, essential for everything from finding food and mates to defending against predators. While humans rely heavily on sight and sound, insects have evolved to use a different, more ancient medium: chemical signaling. The most important of these chemical signals are pheromones, which are substances secreted by an individual that trigger a specific behavioral or physiological response in other members of the same species. This chemical language is remarkably potent; a single molecule of a pheromone can be enough to elicit a reaction from a great distance. It is a silent, invisible world of communication that governs nearly every aspect of an insect's life.
Paragraph 2
Pheromones can be broadly classified into two types based on their function: releaser pheromones and primer pheromones. Releaser pheromones have an immediate, direct effect on the behavior of the recipient. A classic example is the alarm pheromone. When an ant's nest is disturbed, some ants will release an alarm pheromone that quickly spreads, causing other ants in the vicinity to become aggressive and ready to defend the colony. Sex attractant pheromones are another common type of releaser. A female moth, for instance, might release a plume of sex pheromones that males can detect miles away, enabling them to home in on her location for mating. These signals are typically volatile, meaning they evaporate and disperse quickly, and are effective for short-term communication.
Paragraph 3
In contrast, primer pheromones work on a much slower timescale, triggering long-term physiological changes rather than immediate behavioral ones. They are fundamental in regulating the social structure and development of insect colonies. For example, in a honeybee colony, the queen bee constantly produces a special 'queen substance' pheromone. This primer pheromone is passed throughout the hive via contact and food sharing. Its presence inhibits the development of ovaries in the female worker bees, ensuring that the queen remains the sole reproductive individual in the colony. If the queen dies and the pheromone signal disappears, the physiological effect is reversed, and some worker bees will begin to develop ovaries to lay eggs, attempting to produce a new queen.
Paragraph 4
Insects also use trail pheromones to create chemical maps of their environment. Foraging ants, upon discovering a food source, will lay down a trail of pheromones on their journey back to the nest. Other ants can then detect this trail and follow it directly to the food. The strength of the trail can even communicate information about the quality and quantity of the food source; more ants will reinforce the trail if the food is particularly rich, creating a stronger signal that attracts even more foragers. This collective behavior allows the entire colony to efficiently exploit resources that a single ant could not. The trail evaporates over time, so that old, depleted food sources are no longer marked, preventing wasted effort.
Paragraph 5
The specificity of pheromones is one of their most crucial features. Each pheromone is a unique chemical compound, or a specific blend of compounds, that is recognized only by members of the same species. This prevents communication from being intercepted or misunderstood by other species, including predators or competitors. This species-specificity is vital for reproductive isolation, ensuring that insects do not waste time and energy attempting to mate with an incompatible partner. Scientists have harnessed this knowledge in agriculture, developing synthetic pheromone traps that lure specific pest insects, disrupting their mating cycles without the need for broad-spectrum chemical pesticides that can harm beneficial insects.
The word 'potent' in paragraph 1 is closest in meaning to...
The word 'vicinity' in paragraph 2 is closest in meaning to...
According to paragraph 2, what is the main purpose of a sex attractant pheromone?
What happens in a honeybee colony if the queen dies, according to paragraph 3?
What can be inferred about trail pheromones from paragraph 4?
In paragraph 5, why does the author mention the use of synthetic pheromone traps in agriculture?
What does the passage imply about the difference between primer and releaser pheromones?
What is the primary function of the 'queen substance' in a honeybee hive?
Look at the four squares [■] that indicate where the following sentence could be added to paragraph 2. Where would the sentence best fit?
This signal is a call to arms for the whole community.
An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
Pheromones are a vital form of species-specific chemical communication that governs most aspects of insect life.
Select 3 answer choices that express the most important ideas in the passage. This question is worth 2 points.