Ecology (S7L4)

S7L4. Students will examine the dependence of organisms on one another and their
environments.
a. Demonstrate in a food web that matter is transferred from one organism to another
and can recycle between organisms and their environments.
b. Explain in a food web that sunlight is the source of energy and that this energy moves
from organism to organism.
c. Recognize that changes in environmental conditions can affect the survival of both
individuals and entire species.
d. Categorize relationships between organisms that are competitive or mutually
beneficial.
e. Describe the characteristics of Earth’s major terrestrial biomes (i.e. tropical rain
forest, savannah, temperate, desert, taiga, tundra, and mountain) and aquatic
communities (i.e. freshwater, estuaries, and marine). 

This was the first unit we covered this year. We learned about biomes, relationships between animals, environmental footprint, loss of energy, and food webs. This unit took us approximately from the beginning of the year all the way to November, with learning biomes being the longest. 

The 7 major biomes of the Earth are: coniferous (also called temperate deciduous forest) forest, taiga, desert, tundra, rain forest, savanna, and grassland. Biomes can be classified in many ways. Temperature, percipitation and vegetation are two major ways biomes can be classified. 

We also learned about our ecological footprint. In other words, it's the amount of land and sea we need to sustain what we consume and our wastes on a yearly basis. Our ecological footprint also has an impact on other species living on Earth. Say everyone in the US has a high ecological footprint. That's a few million people with maybe a hundred million pounds of waste. Where does this waste go? It's not like it just flies away or anything. This can impact organisms in an environment. Take nuclear waste from a power plant for example. Doesn't nuclear radiation mutate animals? 

Food webs were another important aspect of unit 1. They display which organisms eat one another in an ecosystem. Another important part of a food web is how the amount of energy decreases as the food web goes on. This is called the 10% rule. This means that The next consumer only gains 10% of the original energy from the previous organism. For example, the producer gets 100% energy from the sun. The next organism, let's say a rabbit, eats the plant. It only gets 10% of the energy because the other 90% was used for the plant's functions. The next organism in the foodweb, let's say in this case, a wolf, eats the rabbit. It would only get 1% of the initial energy from the sun; as 90% of the 10% were used for the rabbit's functions.

The last part of unit 1 was relationships between animals. These were split into 2 types: opposition and symbiotic. Opposition is basically when 2 organisms fight for something, like for a mate. It can also be predator and prey relationships. The second kind of relationship, symbiotic, involves 2 organisms helping, in which at least 1 organism is helped out by it. The first symbiotic relationship is mutualism. Mutualism is when 2 organisms help each other out. One of the most widely known case of mutualism is between the anemone and clownfish. The clownfish helps keep away the anemone's predators, such as butterfly fish, while obtaining scraps from the anemone and being able to use the anemone has a home. The second kind of relationship is commensualism. Unlike mutualism, only 1 organism is helped, but the other one is not or helped. harmed. An example of this is a bird and a tree. The bird gets to make a nest on the tree, using it as a home, while the tree gets nothing in return. The final kind of relationship is parasitism. In this relation, one organism is helped, but the other organism is harmed. The keyword in this is parasite, or an organism that attaches itself to the host, and getting nutrients from it at the host's expense. Think of a mosquito and a person. The mosquito feeds on the person's blood, taking away oxygen and other nutrients that are vital to cells, while also possibly transferring diseases.

I hope you learned something from this review of ecology, or just remembered something small that you forgot earlier in the year.

More to come soon!

-Jerome