【正确答案】Key points: Sunlight is an abiotic factor. Sunlight provides the energy for plants to make food. The amount of sunlight affects seasonal events, such as the flowering of plants and the migration of birds. Rainfall and temperature affect plants, which in turn affect the availability of food, nest sites, and shelter for animals. Air temperature affects the ability of plants and animals to regulate their body temperature. Wind is an abiotic factor. Wind increases the effects of air temperature. Wind chill increases heat loss in organisms. Wind causes water loss in animals and plants.

【答案解析】[解析] Ecosystems are made up of both living and nonliving components. The nonliving--or abiotic---components of ecosystems include physical factors such as sunlight, rainfall, temperature, and wind. The abiotic factor of sunlight provides the energy that drives ecosystems. Almost all forms of life get their energy from sunlight. Plants use sunlight to manufacture their food. Sunlight is important to the development and behavior of many plants and animals that are sensitive to the relative lengths of day and night. The amount of daylight is a signal for seasonal events, such as the flowering of plants and the migration of birds. Rainfall and temperature are abiotic factors that affect habitats and food supplies in several ways. Climate greatly influences the plant community, which then determines the availability of food, nest sites, and shelter for animals. Air temperature is an important factor because of its effect on biological processes. Air temperature affects the ability of organisms to regulate their body temperature. Not all plants and animals can maintain an active metabolism at very low or very high temperatures. The abiotic factor of wind increases the effects of air temperature--what we call the wind chill factor, the combined effect of wind speed and air temperature. Wind chill increases heat loss in organisms. Wind also causes water loss in organisms by increasing the rate of evaporation in animals and the rate of transpiration in plants. Using points and examples from the lecture, explain how various abiotic factors in ecosystems affect plants and animals.