Integrated Science Past Paper 1st Secondary Grade - Chapter 2

Integrated Science st TheII 1 Secondary Grade Chapter 2 Lesson 2 : Physical Factors in the Atmosphere The physical factors and their effect on the atmosphere : ⯁ First: Heat The Sun's Heat and Earth's Atmosphe...

Integrated Science st TheII 1 Secondary Grade Chapter 2 Lesson 2 : Physical Factors in the Atmosphere The physical factors and their effect on the atmosphere : ⯁ First: Heat The Sun's Heat and Earth's Atmosphere: The Sun is the primary source of heat and light for Earth. When sunlight reaches Earth, it warms the land and water. This heat is then transferred to the atmosphere, warming the air closest to the surface. Different parts of the Earth receive different amounts of sunlight, leading to variations in temperature. These temperature differences drive weather patterns, including wind, rain, and storms. ⯁ Measuring air temperature Meteorologists measure air temperature to understand weather pattern, they compare current temperatures to past records. Temperature is measured using different scales: Celsius (°C) - used in many countries, including Egypt. Fahrenheit (°F) - used in the United States. Kelvin (K) - used in scientific calculations. To convert between these scales, you can use the following formulas: Celsius to Fahrenheit : F = (9/5) °C + 32 Fahrenheit to Celsius : C = (F - 32) x 5/9 Celsius to Kelvin: K = C + 273 Kelvin to Celsius: C = K — 273 01063200774 44 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade Mechanisms of heat transfer. Heat is generally transferred in three ways : 1- Conduction: heat is transferred in a solid object or between two objects in contact, from one particle of the body in the region of higher temperature to neighboring particles in regions of lower temperature without being transferred. Some materials characterized by good thermal conductivity, such as metals, and others have low thermal conductivity, such as wood. 2- Convection: Heat is transferred through fluids by convection currents, where the higher-temperature parts of the fluid are less dense than the lower-temperature parts and the higher- density parts of the fluid begin to rise through it and are replaced by denser parts. Have you ever seen a bird soar without flapping its wings? This is not just a beautiful sight; it is the result of birds utilizing what is known as thermal flight. Thermal flight is a technique a bird uses to stay in the air for long periods of time without constantly flapping its wings, saving energy. The bird floats above the rising hot air currents by convection and maintains its altitude 3- Radiation: is the transfer of heat in the form of electromagnetic radiation. Thermal radiation propagates in all directions without the need for material medium. It can propagate in a vacuum, as well as through gases. Fire: The heat energy from the fire causes the atoms and molecules in the fuel to vibrate and emit electromagnetic waves. These waves, including infrared radiation, carry energy away from the fire. When this radiation strikes an object, it is absorbed, causing the object's temperature to increase. This process is a fundamental principle of heat transfer and is responsible for how we feel the warmth of a fire. 01063200774 45 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade ⯁ Second - Atmospheric Pressure: Pressure Differences: Differences in atmospheric pressure create wind. Air moves from areas of high pressure to areas of low pressure. Low-Pressure Systems: Characterized by rising warm air. They often bring cloudy skies, precipitation, and stormy weather. High-Pressure Systems: Characterized by sinking cool air. They typically bring clear skies and stable weather. Impact of Atmospheric Pressure on Human Health: High-Altitude Effects: At higher altitudes, atmospheric pressure is lower. This can lead to altitude sickness, characterized by symptoms like headache, nausea, and shortness of breath. Oxygen Availability: Lower atmospheric pressure at higher altitudes means lower oxygen levels in the air. This can affect the body's oxygen supply, especially for people with respiratory conditions. Body's Response: To compensate for the reduced oxygen availability, the body produces more red blood cells. Red blood cells are responsible for carrying oxygen to the body's tissues. Increased Oxygen-Carrying Capacity: By increasing the number of red blood cells, the body can improve its ability to transport oxygen to tissues, even in low-oxygen environments. This adaptation helps people living at high altitudes to function normally, despite the lower oxygen levels. However, it can also lead to some side effects, such as increased blood viscosity, which can strain the heart. Blood Pressure: Changes in atmospheric pressure can affect blood pressure, particularly in individuals with certain medical conditions. Coriolis Effect: The Earth's rotation deflects wind patterns, influencing weather systems. 01063200774 46 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade ⯁ Third - Humidity: Humidity: The Amount of Water Vapor in the Air High humidity: can lead to more clouds and rain, especially in tropical regions. Temperature affects humidity: warmer air can hold more water vapor. Saturated air: is air that can't hold any more water vapor. A hygrometer: is a tool used to measure humidity. High Humidity: Reduced Sweat Evaporation: When the air is humid, it's already saturated with water vapor. This makes it difficult for sweat to evaporate from your skin, which is the body's primary cooling mechanism. Increased Perceived Temperature: The combination of high temperature and high humidity can make it feel much hotter than the actual temperature, leading to heat stress and discomfort. Low Humidity: Dry Skin: Low humidity can dry out the skin, leading to dryness, irritation, and increased susceptibility to skin infections. The effect of humidity on living organisms Plants: High humidity slows down the rate at which plants lose water through their leaves (transpiration). which reduces the rate of lifting water and salts from the root to the leaves. This can affect how well plants grow and absorb nutrients. Animals: the rate of evaporation of sweat decreases, which reduces the efficiency of lowering their body 01063200774 47 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade ⯁ Fourth: Wind Speed: The movement of air from areas of high atmospheric pressure to areas of low atmospheric pressure. Wind affects the distribution of heat and moisture in the atmosphere, which affects the climate in different regions. Strong winds can lead to significant changes in the weather. Drastic changes in the weather lead the life form to adapt accordingly. Adaptation It is the effect of climate factors on living organisms Climate affects the distribution, growth, behavior, and even the evolution of organisms over time. Organisms show remarkable abilities to adapt to extreme environmental changes. 1.Adaptation to Freezing: The Wood Frog: The wood frog lives in cold northern regions like Alaska and Canada, where temperatures drop below freezing. In winter, the wood frog's body partially freezes—its heart stops beating, and it stops breathing. Surprisingly, the frog does not die in this state but instead enters a deep hibernation until spring arrives and the snow melts, allowing it to thaw and resume normal function. The wood frog produces large amounts of glucose in its vital organs (heart, liver, brain) before freezing. The glucose acts as an antifreeze, preventing the formation of ice crystals in the cells and protecting them from damage. When temperatures rise in the spring, the ice melts, the heart starts beating again, and the frog’s bodily functions resume without harm. Antarctic Icefish: This species of fish lives in the freezing waters of Antarctica, where water temperatures drop below zero—conditions that are deadly for most marine life. However, the icefish adapts to this frozen environment in remarkable ways by secreting special proteins in its blood known as antifreeze proteins. These proteins prevent the formation of ice crystals in the fish's blood and tissues, allowing it to survive in subzero temperatures. The Antarctic icefish is one of the rare species whose blood does not contain hemoglobin (the pigment responsible for transporting oxygen in blood). Instead, it absorbs oxygen directly from the oxygen-rich waters of the extremely cold Antarctic. 01063200774 48 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade 2. Adaptation to High Temperatures: Desert Lizards: can reach dangerously high levels that are lethal for many other organisms. However, desert lizards have developed unique adaptations that allow them to survive in these harsh environments. These adaptations include behavioral strategies like seeking shade or burrowing during the hottest parts of the day, and physiological features such as efficient water retention and the ability to tolerate high body temperatures. The thorny devil lizard from the Australian desert has small channels on the surface of its skin that help it collect moisture from the air or even from the sand. These channels direct the water toward its mouth, allowing the lizard to stay hydrated in an extremely dry environment. 01063200774 49 ENG / Mahmoud FATHY