Monarch butterflies undertake one of the most remarkable migration journeys in the natural world, traveling thousands of kilometers across North America every year. Their migration is primarily driven by seasonal changes and the search for suitable breeding and feeding grounds. The migration cycle spans multiple generations, with different groups of butterflies contributing to the overall journey.
In the spring and summer months, monarch butterflies begin their journey northward from overwintering sites in Mexico and the southern United States. They travel to regions in the northern United States and Canada, seeking milkweed plants, which serve as both a food source and a breeding ground. The butterflies lay their eggs on milkweed leaves, ensuring that the next generation has access to nourishment upon hatching.
The northward migration occurs over several generations, each with a lifespan of a few weeks. As the butterflies progress further north, they reproduce and continue the cycle. The final generation to emerge in late summer is unique, as it does not reproduce immediately but instead prepares for the long journey back to warmer climates.
During autumn, the monarchs begin their southward journey. This generation, known as the migratory generation, is physically distinct from the earlier generations. They possess larger bodies and longer wings, which enable them to cover greater distances. Environmental cues such as temperature and daylight guide their navigation towards the forests of central Mexico.
Once they arrive in Mexico, the butterflies cluster in trees to survive the winter months. They enter a state of reduced metabolic activity to conserve energy. This period of dormancy is critical, as it allows them to survive until the return of warmer conditions.
Monarch butterflies face numerous challenges during their migration. Habitat destruction, climate change, and the reduction of milkweed plants due to agricultural expansion pose significant threats to their survival. Conservation initiatives focus on habitat restoration and public awareness campaigns to protect these vital pollinators.
Scientists study monarch migration using various methods, including tracking devices, citizen science initiatives, and genetic analysis. These approaches help researchers understand migration routes, monitor population trends, and identify critical habitats for conservation efforts.
Flowchart Completion Questions
Complete the flowchart below. Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the text for each answer.
Monarch butterflies leave (1) __________ in spring. ↓
Travel northward in search of (2) __________ plants. ↓
Multiple generations reproduce and continue migration. ↓
The (3) __________ generation begins the southward journey. ↓
Arrive in Mexico and cluster in (4) __________. ↓
Enter a state of reduced (5) __________ to survive winter. ↓
Threats include habitat loss and decline of (6) __________.
Answer Key and Explanation
overwintering sites Hint: Second paragraph. The passage states that “Monarch butterflies begin their journey northward from overwintering sites in Mexico and the southern United States.”
2. milkweed Hint: Second paragraph. Monarchs seek milkweed plants as both a food source and breeding ground.
3. migratory Hint: Fourth paragraph. The passage mentions that the migratory generation is the one that embarks on the journey back south.
4. trees Hint: Fifth paragraph. Monarchs cluster in trees to survive the winter months.
5. metabolic activity Hint: Fifth paragraph. The passage describes how monarchs enter a state of reduced metabolic activity.
6. milkweed Hint: Sixth paragraph. The passage highlights the reduction of milkweed plants as a major threat to their survival.
● ONE WORD ONLY もしくは NO MORE THAN TWO WORDS という語数の指定があります。
例題：
The Effects of Air Pollution on Human Health and the Environment
Air pollution has become a critical issue affecting human health and ecosystems worldwide. It is primarily caused by emissions from industries, vehicles, and agricultural activities, releasing harmful substances like particulate matter (PM), nitrogen oxides (NOx), and sulfur dioxide (SO2) into the atmosphere. These pollutants have far-reaching consequences for both human health and the environment.
One of the most concerning impacts of air pollution is its effect on respiratory health. Fine particulate matter (PM2.5) can penetrate deep into the lungs, causing inflammation and exacerbating conditions like asthma and bronchitis. Long-term exposure to polluted air is linked to severe diseases such as lung cancer and cardiovascular complications. Vulnerable populations, including children and the elderly, are particularly at risk. For instance, studies have shown a significant increase in hospital admissions for respiratory issues during periods of high air pollution.
Air pollution also has a substantial impact on the environment. Acid rain, formed when sulfur dioxide and nitrogen oxides react with water vapor, damages soil, water bodies, and vegetation. It alters the pH of aquatic ecosystems, making them unsuitable for many species. Additionally, the deposition of pollutants on leaves and soil can inhibit plant growth and reduce crop yields. Ozone, a secondary pollutant formed through the reaction of sunlight with volatile organic compounds (VOCs) and nitrogen oxides, is particularly harmful to plant life. High levels of ozone can damage the leaves of plants, affecting their ability to photosynthesize and reducing agricultural productivity.
Another significant issue caused by air pollution is its contribution to climate change. Carbon dioxide (CO2) and methane (CH4), both greenhouse gases, trap heat in the atmosphere, leading to global warming. Short-lived pollutants like black carbon also play a role in heating the atmosphere. Black carbon, produced from the incomplete combustion of fossil fuels and biomass, not only absorbs heat but also accelerates the melting of snow and ice in polar regions.
Efforts to combat air pollution include government regulations and technological advancements. Policies such as the implementation of emission standards for vehicles and industries aim to reduce the release of harmful pollutants. For example, the introduction of cleaner fuels and electric vehicles is helping to lower air pollution in urban areas. Technological innovations like air purifiers and carbon capture systems are also playing a significant role in mitigating the effects of air pollution.
Raising awareness about the dangers of air pollution is crucial for its prevention. Public campaigns and educational initiatives can help individuals adopt eco-friendly practices such as using public transportation, conserving energy, and supporting renewable energy sources. Collaborative efforts between governments, industries, and communities are essential to address this global challenge effectively.
Note Completion Task
Complete the notes below. Choose ONE WORD ONLY from the passage for each answer. Write your answers in boxes 1-6 on your answer sheet.
Effects of Air Pollution on Health:
Fine particulate matter can cause (1) __________ in the lungs.
Long-term exposure is linked to diseases like lung cancer and (2) __________ complications.
(3) __________ populations are especially at risk, including children and the elderly.
Environmental Consequences:
Acid rain damages (4) __________, water bodies, and vegetation.
High levels of (5) __________ inhibit plant growth and reduce crop yields.
Black carbon contributes to the melting of (6) __________ in polar regions.
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Answer Key
inflammation
Hint: Paragraph 2 describes how fine particulate matter causes inflammation in the lungs.
Reason: Inflammation is a direct consequence of PM2.5 exposure, as mentioned in the text.
cardiovascular
Hint: Paragraph 2 links long-term air pollution exposure to cardiovascular complications.
Reason: This is a specific disease category associated with air pollution effects.
vulnerable
Hint: Paragraph 2 highlights that vulnerable populations, such as children and the elderly, are at greater risk.
Reason: “Vulnerable” is the term used to describe these groups in the passage.
soil
Hint: Paragraph 3 discusses how acid rain affects soil, water bodies, and vegetation.
Reason: Soil is explicitly mentioned as one of the elements damaged by acid rain.
ozone
Hint: Paragraph 3 explains the harmful effects of high ozone levels on plants.
Reason: Ozone inhibits photosynthesis and agricultural productivity.
ice
Hint: Paragraph 4 refers to how black carbon accelerates the melting of snow and ice in polar regions.
Reason: Ice is explicitly mentioned as being affected by black carbon.
4. Diagram Completion（図表完成）
特徴:
イラストや図表が与えられ、それを基に空欄を埋める。
形状や位置関係、説明文を理解する力が求められる。
攻略法:
図を分析: 図のラベルや注釈を確認して、全体像を把握する。
位置関係を意識: 空欄が図のどの部分に対応するかを明確にする。
関連語句を抽出: 図とテキストの対応箇所を正確に見つける。
例題:
Diagram of a Water Cycle:
Evaporation
Precipitation
Question: Label the diagram using NO MORE THAN TWO WORDS.
解答ヒント:
テキスト内で”evaporation”と”precipitation”の間に当たる段階を探す。
“After evaporation, condensation occurs as water vapor cools.”という記述があれば、答えは”Condensation”。
