Competitive exclusion (see p 429) may occur between two species that compete for the same resources. In this situation, only one species will be successful, such that the other species is forced to move elsewhere or die out. This rarely happens in nature though, since the species on the losing end typically switches to an alternate resource. However, under artificial situations, elimination of one species can occur.

Read through the introductory materials below.
Open the Unit 8 Experiment Answer Sheet and complete the following Experiment exercises this unit:
Experiment 8 Exercise 1 – Species Interactions: Competition
Experiment 8 Exercise 2 – Biomes
Species Interactions: Competition – Introduction

This unit we are learning about species-species interactions and how species influence each other (see pp 428-432 and our online lecture). One important interaction is interspecific competition, in which two or more species compete for limited resources. Competition, along with predation and symbioses (e.g., commensalism, mutualism, and parasitism) are important biological interactions that affect the size of species populations.

In the first exercise, we will examine the population growth of two species of freshwater ciliates. Populations of these species initially grow exponentially (see p 408), but the population does not increase in size forever. Eventually it reaches what is known as the carrying capacity of the environment, or the maximum population size the environment can support due to limitations in food, water or other resources.

Competitive exclusion (see p 429) may occur between two species that compete for the same resources. In this situation, only one species will be successful, such that the other species is forced to move elsewhere or die out. This rarely happens in nature though, since the species on the losing end typically switches to an alternate resource. However, under artificial situations, elimination of one species can occur.

The purpose of this exercise is to use a simulation to model competitive exclusion using the microscopic organisms that Gause used to come up with his competitive exclusion principle (see p 429). You will need to use the following website. Be sure you can access it and use it:

Glencoe/McGraw Hill. No date. Population Biology
http://www.mhhe.com/biosci/genbio/virtual_labs/BL_04/BL_04.html (Links to an external site.)

When you are ready to begin, go to the above website and open the Unit 8 Experiment Answer Sheet and follow the instructions.

In Biomes – Introduction

This unit we have learned about the large scale ecosystems called Biomes. They have developed over millions of years and the flora and fauna found in each biome type have adapted to the long term climate conditions (e.g., average rainfall, average temperatures). The purpose of this exercise is to see how well you understand the biotic and abiotic factors that shaped the various biomes. Review pp 384-390 and our online lecture this unit before beginning.

You will need to use the following websites. Be sure you can access them and use them:

NASA. No date. The Great Graph Match
http://earthobservatory.nasa.gov/Experiments/Biome/graphmatch_advanced.php (Links to an external site.)

NASA. No date. To Plant or Not to Plant
http://earthobservatory.nasa.gov/Experiments/Biome/plant_it.php (Links to an external site.)

When you are ready to begin, open the Unit 8 Experiment Answer Sheet to complete this exercise.

For your primary post, select ONE of the following discussion topics. Please select only one of the three topics listed. Using your own words, write a primary post of at least 125 words that follows the instructions. Be sure to address everything listed in the instructions. Each topic has two subtopics [a, b]; please address both of them.
“Evo-devo, Medical Revolutions and Human Survival”

For your primary post, select ONE of the following discussion topics. Please select only one of the three topics listed. Using your own words, write a primary post of at least 125 words that follows the instructions. Be sure to address everything listed in the instructions. Each topic has two subtopics [a, b]; please address both of them.

Your primary post is worth up to 14 out of 20 points. Also, make a substantive reply to a fellow classmate on any topic. Use your own words. You don’t need to use any sources other than the ones specified, but if you do use other sources, you must cite them.

Topic 1 : Evo-devo. Watch the video (1)* featuring Sean Carroll discussing the science of evolution and the field of evolutionary-developmental biology (evo-devo).

(a) Describe three things that you learned from the video.
(b) Of the three things you described, which was the most surprising, and why?
(c) Discuss what these things teach us about biology.
Topic 2 [article]: The cusp of a revolution in medicine. In a recent op-ed, Craig Venter (2)* shares his opinion that we are “on the cusp of a revolution” in medicine.

(a) Describe three things that you learned from this op-ed.
(b) Of the three things you describe, which was the most surprising, and why?
(c) Discuss what these things teach us about biology.
Topic 3 [article]: Earth will survive; we may not. In a provocative Op-Ed, astrophysicist Adam Frank says that “pretending we can just extend the Holocene in perpetuity” is just a foolish excuse to put off making inevitable choices brought about by climate change.

(a) Summarize Frank’s basic argument.
(b) Some biologists, particularly conservation biologists reacted negatively to this essay. What is your reaction to this essay?
(c) Explain how this relates to biology.
*References (in Strayer Writing Standards format).

Erik Olsen, June 25, 2007, Sean Carroll on evolution and the science of evo-devo, https://www.nytimes.com/video/science/1194817104756/the-science-of-evolution.html
Craig Venter, December 13, 2017, Genetic sequencing is the future of medicine, https://www.washingtonpost.com/news/theworldpost/wp/2017/12/13/human-genome/
Adam Frank, June 12, 2018, Earth will survive. We may not., https://www.nytimes.com/2018/06/12/opinion/earth-will-survive-we-may-not.ht

1.What is the overall hypothesis of this experiment? (Reminder: a hypothesis is a statement that can be tested).

Written Assignment 1: Trace the Scientific Method in a Primary Research Scientific Article

Addresses course outcomes 1 and 4:

•use knowledge of biological principles and the scientific method to ask and answer relevant questions about the human body

•weigh and make health-related decisions based on an understanding of the value and limits of scientific knowledge and the scientific method

Before attempting this assignment, you might want to revisit the Scientific Method Tutorial in the Science Learning Center under the Course Content area.

Substance in Green Tea Inhibits Inflammatory Breast Cancer Cells

Inflammatory breast cancer (IBC) is a rare and often fatal form of breast cancer. In IBC, lymphatic vessels in the skin are blocked causing the breasts to appear swollen and red. Early in the disease process, patients with IBC usually do not have the classic “lump” in their breast; therefore the disease is frequently diagnosed at later stages. Diagnosis is often so delayed that the cancer has metastasized and patient prognosis is poor.

The underlying cause of IBC is unknown, but it is believed that like with other cancers cetain cell types have the abililty to transform into cells that can form malignant tumors. These aberrant cells are considered cancer stem cells, and populations of cancer stem cells have been identified in IBC.

In a recent, study researchers evaluated whether a metabolite found in green tea could inhibit the growth of certain stem cell types that have been identified in the breast tissue of patients with IBC. In this study, two IBC stem cell types, SUM-149 and SUM-190, were exposed epigallocatechin-3-gallate (EGCG- is a potent antioxidant found in green tea). Results from the study showed that EGCG treatment inhibited the growth, spread, and survival of the two stem cell types.

For the following questions, please refer to the original paper. The link to the paper is:http://www.plosone.org/article/fetchObject.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0073464&representation=PDF

1.What is the overall hypothesis of this experiment? (Reminder: a hypothesis is a statement that can be tested).

2.In the Materials and Methods section of the paper, the authors discuss the cell culture and treatment conditions. What was the control group treated with in this section (make sure to look only at the Cell Culture and Treatment section of the paper)? Why?

3.Again, looking only at the Cell Culture and Treatment section, what was the experimental group treated with? Why?

4.In the Results section of the paper, the authors clearly summary their multiple findings. In the “EGCG Reduces Growth of Pre-existing Tumors Derived from SUM-149 Stem-like Cells” results sub-section, the authors report a specfic finding. What specific result do the researchers report?

5.Did the researchers follow the scientific method in their experimental design? Explain.

6.Based on the results, was the hypothesis supported, and what can you conclude from this experiment?