Prokaryotes and Eurkaryotes

Page 1: In this module, you’ve learned about prokaryotes, and some of the various ways they can interact with other eukaryotic species – in positive and negative ways. For this assignment, you’re going to be looking in more detail at some prokaryotes that live in symbiotic relationships with various eukaryotic species. Symbioses are long-term associations between two species – symbiosis literally means “living together”. In everyday speech, when people use the term “symbiotic relationship”, they normally mean to imply that the association is beneficial to both species, but this is more properly called a mutualism, or mutualistic relationship. There can be symbiotic relationships in which one species benefits at the expense of the other, which are usually termed parasitic relationships, or symbiotic relationships in which one species benefits, but has no effect on the fitness of the other (doesn’t help or hurt), which are called commensalistic relationships.

For this assignment, you’re going to use the internet to investigate some of the various types of well-known symbiotic relationships between prokaryotes and eukaryotes in the world today. For each of the five cases below, please write a paragraph that explains the relationship and how it works, making sure that you address each of the following four questions:

What prokaryotic species might you find associated in a symbiotic relationship with this eukaryote? Does this prokaryote belong to Bacteria or Archaea?
For some examples, you might not be able to find one specific species. In these cases, provide the smallest group that you can. You should be able to narrow it down more than just “Bacteria” or “Archaea”, however.
Make sure that what you list is actually a prokaryote! Some of these examples also have symbiotic eukaryotes that fulfill a similar function. If the symbiote you find isn’t obviously stated to be in Bacteria or Archaea, do some more searching to make sure.
How do these prokaryotes affect the eukaryote? What benefits do the prokaryotes receive?
Is this a commensalistic, mutualistic or parasitic relationship? Explain.
Is there any broader ecological, environmental, or economic impact to this relationship? In other words, what might happen to these species, to other surrounding species, and/or to human activity if this relationship no longer occurred?

Pages 2: Look around your house or yard and think about all the different types of eukaryotes you live with/near every day. Chances are, you have never given much thought to the diversity you have around you. Pick a location (your house/dorm room, back yard, or a nearby park or a lake) and then find at least twelve species of eukaryotes in that location. (If you can’t find at least twelve species, pick a different location – it might be a nice time for a trip to Lake Alice, the Natural Area Teaching Lab (Links to an external site.), or a local park!) Your twelve species must include at least one fungus, three plants, three chordates, and three non-chordate animals. The remaining two species can come from any of the categories.

Your submission should include:

1. A brief description of the location where you’ve found your eukaryote species, with at least one picture of yourself in the location that you’re describing. This can be added directly into your document, or submitted as a separate file. You do not need to include a picture of every species you list, although you can if you’d like, and especially if you find something cool!

2. A list of your twelve species (common names are okay, although you need to be more specific than just “tree” or “bush”, etc.), along with a general description of where you found them / what they were doing, organizing them into the categories below. For example, under Arthropods, I might put “Small brown spiders spinning cobwebs near my back door”

3. In addition to your list, we’re asking you to create a dichotomous key to your twelve species. If you haven’t used a dichotomous key before, it’s a series of questions, each with only two possible answers (often “yes”/”no”), that lead to different endpoints based on how you answer each one. You can format this as a list, or as a flowchart. Both options are illustrated below in a possible dichotomous key for identifying your Halloween candy.