1. HOMEROOM READ!!

2. W ARM - UP 1. Does Mitosis occur in sexual or asexual reproduction? 2. Do offspring have a greater variety with sexual or asexual reproduction? 3. Who created the Punnett Square? 4. What is the difference between genotype and phenotype? 5. What is the difference between heterozygous and homozygous?

3. C OMPOSITION OF THE ATMOSPHERE - REVIEW Nitrogen 78% Oxygen 21% Argon, CO 2 and other gases 1%

4. L AYERS OF THE ATMOSPHERE - REVIEW There are 4 layers of the atmosphere Troposphere Stratosphere Mesosphere Thermosphere

5. TROPOSPHERE Closest layer to Earth The first 0-10 km (0-6 miles) of the atmosphere Temperature decreases with increasing altitude Temperature goes down as height increases Weather occurs in this layer Planes fly in this layer

6. S TRATOSPHERE From 10km to 50km (6 to 31 miles) Temperature increases with increasing altitude Temperature rises with height This is because the ozone layer located in the stratosphere absorbs radiation from the sun This is important for Earth… the ozone layer absorbs harmful radiation from the sun.

7. M ESOSPHERE 50-90 km (31-56 miles) Temperature decreases as altitude increases Temperature goes down with height This is due to the mesosphere being heated by the stratosphere below. Most meteors that enter the atmosphere burn up here.

8. T HERMOSPHERE 90 km (56 miles) and up Temperature increases as altitude increases Radiation from the sun heats the thermosphere Satellites orbit in this layer

9. A IR P OLLUTION R EVIEW Air Pollution – smoke and other harmful materials in the air Particulates – tiny particles mixed in with the air. (dust, dirt, pollen, salt) Fossil Fuels – fuels formed from the remains of prehistoric animals and plants (coal) Smog – Combo of smoke and fog Ozone – a pollutant caused by human use of aerosols and CFCs. Ozone is harmful to humans when in the troposphere but beneficial when in the stratosphere.

10. G REENHOUSE E FFECT Keeps Earth’s surface warm Certain gases in the atmosphere help to keep energy (heat) towards the surface of Earth Carbon dioxide, methane, water vapor, and nitrous oxide These gases are known as greenhouse gases Called the Greenhouse Effect because it’s similar to how a greenhouse works Without the greenhouse gases, Earth’s surface would be about -18 degrees C (0 degrees F)

11. C LASSWORK Complete the worksheet. Refer to page 20A in your textbook