Exam Review Notes

Hadley Cell Circulation:

  • At the equator (the middle of the Earth, 0 degrees latitude), the sun heats up the air.
  • This warm, moist air rises high into the sky and makes it rain a lot over rainforests.
  • After the air cools, it moves away towards the north and south, cooling down even more and becoming dry.
  • When this dry air sinks back down at 30 degrees North and South latitude, it warms up again. This makes places like deserts where it hardly rains, like the Sahara Desert, which is around 30 degrees North.

Rain Shadow Effect:

  • When the warm, wet air comes from the ocean and hits mountains, it has to go up.
  • As the air rises, it cools off and makes clouds that rain on one side of the mountain (the windward side).
  • The other side of the mountain (the leeward side) doesn't get any rain. Instead, it becomes dry and hot, like the deserts found there.

Biome Types:

  • Rainforests: Very warm and wet places with lots of tall trees and plants.
  • Savannas: Open grassy places where animals like giraffes roam and it has wet and dry times in the year.
  • Deserts: Very hot and dry places where plants like cacti grow that can live without much water.
  • Boreal Forest/Taiga: Cold forests found in Canada and Russia where it rains a lot and has pine trees.
  • Tundras: Very cold and dry areas near the top of the Earth, where trees cannot grow because the ground is frozen (called permafrost).
  • Deciduous Forests: Forests with trees that lose their leaves in winter, found in places like the Eastern United States.
  • Grasslands: Flat areas where lots of grass grows, good for animals like cows and horses.
  • Chaparral/Scrub Areas: Hotter places that can catch fire easily, like in California.

Biome Locations:

  • Tundras: Far north, where it is very cold.
  • Taigas: Just south of tundras, in Canada and Russia.
  • Deserts: Found north and south of the equator, near rainforests.

Climate and Biome Distribution:

  • The weather, like how hot or cold it is, helps decide where biomes are found.
  • As you move from the North or South Pole towards the equator, it gets warmer and wetter.
  • If you go the other way, it gets cooler and drier.

Aquatic Biomes:

  • Freshwater Biomes: Places like lakes and rivers.
    • Oligotrophic Lakes: Clear lakes with few plants and little algae.
    • Eutrophic Lakes: Lakes that are full of plants and algae due to many nutrients.
  • Marine Biomes: Ocean areas with lots of sea life.
    • Coral Reefs: Underwater gardens full of colorful fish and coral.
    • Abyssal Zones: Very deep parts of the ocean that are dark and have strange animals that can survive in high pressure.
    • Open Ocean: The large part of the ocean where tiny plants (phytoplankton) live and make oxygen.

Freshwater and Marine Zones:

  • Freshwater Zones:
    • Littoral Zone: Near the edge of lakes with lots of plants and sunlight.
    • Limnetic Zone: The middle part of the lake.
    • Benthic Zone: The bottom part of the lake where detritus is found.
  • Ocean Zones:
    • Photic Zone: Where sunlight reaches the water.
    • Aphotic Zone: Where there is no light in the ocean.
    • Abyssal Zone: Very deep, dark ocean where hot vents exist.
    • Benthic Zone: The seafloor.
    • Intertidal Zone: The shore area that gets covered by water and exposed again with the tides.

Biogeochemical Cycles:

  • Carbon Cycle: Carbon comes from burning things like gas, trees take it in, and we release it when we breathe out.
  • Water Cycle: Water travels from earth to sky and back again through rain, clouds, and evaporation.
  • Nitrogen Cycle: Special bacteria change nitrogen from the air into a form that plants can use.
  • Phosphorus Cycle: Phosphorus is found in rocks and soil; it helps plants grow, but too much can hurt our waters.

Ecosystem Interactions:

  • Biotic factors: Living parts like animals and plants.

  • Abiotic factors: Non-living parts like water, rocks, and sunlight.

  • Symbiosis: Relationships between living things that help them survive or make life easier.

    • Mutualism: Both animals help each other (like bees and flowers).
    • Commensalism: One animal benefits, and the other doesn’t get hurt (like moss growing on a tree).
    • Parasitism: One animal benefits but harms the other (like mosquitoes feeding on blood).

Competition:

  • When animals want the same resources, they compete.
    • Interspecific Competititon: Different types of animals competing.
    • Intraspecific Competition: The same type of animals competing.