Why is it so hot in Las Vegas? (Principles of Science Standards=P.0.S) (Nevada State Standards =NV) (Environmental Science Standards = ENV)

Misconceptions Las Vegas is near the Equator Las Vegas is below sea level Las Vegas’ desert is dead.

What do we know boys and girls? Big Question, Big Paper Brainstorm (To be left in Class throughout unit.) Fun Introductory Activity: (Scientific Method-Mini Lab Report). Problem: Can we fry an egg on the sidewalk? P.O.S. #1.1 NV # N.12.A ENV # 1.2

Misconception 1: Las Vegas is near the Equator Sub Question: How do we know our location? (Brainstorm) Global Positioning System Introduction (US Dept of Defense)

Misconception 1: Las Vegas is near the Equator (continued) Get a GPS reading of Location. Place Las Vegas on a blank World Map. (Determine Longitudinal Lines.) Keep Map in Folder. Brainstorm the question: How does the sun’s energy affect our longitudinal location? (Think-Pair Share, then class discussion.)

Misconception 1: Las Vegas is near the Equator (continued) Use a Physics Sun/Earth demonstration on the Sun’s rays to demonstrate the energy reaching the Earth. Note Conclusions, asking the Sub Question again and Summarizing. ENV # 1.9

Misconception 2: Las Vegas is below sea level. Sub Question: Since we now know our location, how do we know our elevation? (Brainstorm) Topography Introduction: Practice Maps Produce a Topographic Map of the School (List Procedures, Determine how we are obtain data, talk about presentation.) P.O.S. # 1.2 ENV # 1.6; 1.7

Misconception 2: Las Vegas is below sea level. (Continued) Re-ask question: How do we know our elevation? Look at Class Predictions, then show a topographical map of Las Vegas. Summarize in Findings. Go back to the BIG question: Why is it so hot in Las Vegas? (Does Elevation or Longitudinal Line have anything to do with it?)

Big Question Revisited Does Longitude and Latitude Affect Temperature? Does Elevation Affect Temperature? How might Las Vegas become cooler or warmer? Does moisture affect the temperature? (new- brainstorm) Summarize ideas in individual writing. NV # E.12.A NV # P.12.C

Misconception 4: Las Vegas’ desert is dead. Rania… P.O.S. # 5.9 NV # L.12.C; L.12.D ENV # 3.1; 3.3; 3.5; 3.6; 4.1; 4.2

References GPS Information from: tes/gps/gps_f.html tes/gps/gps_f.html Topography Information from:

Why is it so Hot in Las Vegas? Biology Pass Institute Rania Piere and Kirsten Radek

Introduction Students will answer the question based on prior knowledge. The lesson will begin with the student's responses. The students’ responses will be written on the board so all can see and to avoid repetition.

Misconceptions Las Vegas is nearer to the equator, that’s why its so hot. The elevation of the land is below sea level. The increase of the human population.

Conceptions Las Vegas is located in a desert biome. The Sierra Nevada Mountain Range prevents coastal winds from cooling down the Las Vegas. Very little precipitation.

Inquiry Discussion Each conception will be dissected and each misconception will be analyzed. Students need to understand why they are misconceptions: Content Delivery: Biomes Desert Flora Desert Fauna Why are the plants an important factor? Web Inquiry

What is a Desert Biome Like? The desert is a land of extremes: extreme heat and extreme dryness; sudden flash floods and cold nights. Because deserts are such a harsh environment, deserts often have names likes "Death Valley," "the empty quarter," and "the place from where there is no return." Dryness Deserts are usually very, very dry. Even the wettest deserts get less than ten inches of precipitation a year. In most places, rain falls steadily throughout the year. But in the desert, there may be only a few periods of rains per year with a lot of time between rains. When it does rain, there may be quite a downpour! After the rain, desert flowers bloom.

Why the extreme in temperature? Hot During the Day, Cool at Night Everyone knows that during the day many deserts are hot, very hot. Temperatures in excess of 100 degrees Fahrenheit are not uncommon. Yet at night, the same deserts can have temperatures fall into the 40s or 50s? Why? Other biomes are insulated by their humidity (water vapor in the air). Temperate deciduous forests, for example, may have 80 percent humidity or more during the day. This water reflects and absorbs sunlight and the energy it brings. At night the water acts like a blanket, trapping heat inside the forest. Since deserts usually have only between 10 and 20 percent humidity to trap temperatures and have so few trees and other vegetation to retain heat, they cool down rapidly when the sun sets, and heat up quickly after the sun sets.

Types of Deserts Inquiry– In groups students will be asked to compare the temperature of the Mojave and

Desert Flora Deserts are the home to many living things. In fact, deserts are second only to tropical rainforests in the variety of plant and animal species that live there. How do you think plants grow in a place that is very, very dry? Many of the fascinating features of desert plants are adaptations -- traits that help the plant survive in its harsh environment. Desert plants have two main adaptations: Ability to collect and store water Features that reduce water loss Desert plants often look different than plants in any other biome.

Desert Plant Adaptations Desert plants have adapted to the extremes of heat and aridity by using both physical and behavioral mechanisms, much like desert animals. Plants that have adapted by altering their physical structure are called xerophytes. Xerophytes, such as cacti, usually have special means of storing and conserving water. They often have few or no leaves, which reduces transpiration. Phreatophytes are plants that have adapted to arid environments by growing extremely long roots, allowing them to acquire moisture at or near the water table. Other desert plants, using behavioral adaptations, have developed a lifestyle in conformance with the seasons of greatest moisture and/or coolest temperatures. These type of plants are usually (and inaccurately) referred to as perennials, plants that live for several years, and annuals, plants that live for only a season. Desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. Most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly. They bloom prodigiously for a few weeks in the spring, accounting for most of the annual wildflower explosions of the deserts. Their heat- and drought- resistant seeds remain dormant in the soil until the next year's annual rains. Xerophytes The physical and behavioral adaptations of desert plants are as numerous and innovative as those of desert animals. Xerophytes, plants that have altered their physical structure to survive extreme heat and lack of water, are the largest group of such plants living in the deserts of the American Southwest. Each of the four southwestern deserts offers habitats in which most xerophytic plants survive. But each is characterized by specific plants that seem to thrive there. The Great Basin Desert is noted for vast rolling stands of Sagebrush and Saltbush, while in the Mojave Desert, Joshua Trees, Creosote Bush, and Burroweed predominate.southwestern deserts Joshua TreesCreosote Bush

Types of Flora Joshua Tree

Creosote Bush

Mesquite

Why are the plants important? Inquiry– In groups,do the plants play a facoter on the climate of Las Vegas? Students will have time to create a project.

Activities Students will design a Mojave Desert Biomes poster. Web Activity: Pose the same question to a meteorologist.