Chapter 42: Organisms in their Environment
Questions:
1. Abiotic is all the non-living parts of an ecosystem, like the soil, rocks, water, nutrients, etc. Biotic
is all the living parts of an ecosystem, like the animals and bacteria.
2. Weather is the conditions on a certain day, while climate is an overall pattern of weather in an
area over a long period of time. Climate can be predicted and graphed as a generalization, but
with weather, you don’t know until it occurs.
3. The sun rays strike Earth’s surface at steeper angles near the equator (lower altitudes) which
result in more solar energy. Seasonality occurs because of Earth’s rotation on its axis which
causes different latitudes to receive more or less sun at different times of the year. More rain
occurs in the tropics due to Hadley cells, the cells bring up moisture with the warm air. As the
moisture descends, it cools and sticks together to for precipitation. Wind patterns are a result of
the planet’s counterclockwise rotation and north-south atmospheric circulation.
4. The Coriolis Effect drives the surface wind in the tropics to blow east to west, the surface winds
in the mid-latitudes to blow west to east, and east to west by the poles (60+ degrees). These
prevailing surface winds drive the water currents in massive circulation patterns because the
winds blow a frictional drag over the water. The pattern in the southern hemisphere is a mirror
image of the currents in the northern hemisphere.
5. The 9 major biomes, in order by average precipitation, are tropical rainforest, temperate
rainforest, tropical seasonal forest/savannah, temperate seasonal forest, boreal forest,
woodland/shrubland, tundra, subtropical desert, temperate grassland/desert. These are
categorized based on precipitation, temperature, organisms, etc. Many aquatic biomes exist,
too. These are differentiated by water depth and movement, temperature, pressure, salinity,
and characteristics of the substrate.
6. Deforestation is harming any kind of forest because it removes the habitat and the animals have
no place to live, plus increased competition, which makes life extremely difficult. Also,
deforestation removes trees that exchange CO2 for O2, which we need to breathe. Many
biomes are being hurt by increasing amounts of farmland. When industrial farmers tear down
forests, fill in lakes and swamps, or level out hills, they destroy the ecosystem that depended on
those landforms to live. Some say that human pollution is destroying polar ice caps, through
global warming. Pollution is also destroying aquatic biomes, such as coral reefs and kelp forests.
Pollution can destroy corals reefs because the chemicals cause bleaching of the coral and the
algae dies and then the coral itself dies. Tourism along beaches often hurts the local ecosystems
because of unwanted breakage or oils from hands. City expansion hurts shorelines because the
city builders sometimes rebuild the coastlines to allow for more waterfront access and this kills
the current ecosystem. Oil spills hurt the biomes by coating the organisms with oil and making it
hard for them to breathe, feed, etc. Plants cannot perform photosynthesis if they are coated in
crude oil.
7.
8. Aquatic environments differ based on salinity, temperature, velocity of water, nutrients, light,
and abiotic features. Organisms have evolved to fix their environment, and only their
environment. Sure they can adapt, but this takes a long time, too. Certain organisms like snails
cannot live in super salty water because they will dry up, but other fish like sharks have adapted
to survive in the salty ocean water. Temperature is important because some simpler animals
cannot perform homeostasis, so they move to the area that can best control their body temp.
Plants like coral need vast areas of slow moving water to establish a reef. If they were placed
into a forceful river, they couldn’t form reefs or survive. Other animals have adapted to river life
because they can either swim against the current or hide in the ground to avoid being swept
away. Nutrients are essential to life. Again, with coral, the organism itself depends on the algae
to get nutrients, which algae expel as waste. These animals have a symbiotic relationship in
order to survive. Light is a cool phenomenon in the oceans. Layers form underwater based on
how much sunlight organisms need to survive. Phytoplanton need to stay in the photic zone, but
other organisms like the Angler fish don’t need as much sunlight and can stay in the depths of
the ocean. Bigger organisms depend on phytoplankton as food and the phytoplankton use
sunlight to create energy which is transferred to the larger animals when eaten. The
phytoplankton and other nutrients that fall down to feed the organisms of the bethic layer are
called marine snow.