In the examples below, the Student A (leftmost column) earned 99/100 points. Student B (center column) earned 82/100 points; Student C (rightmost column) earned 61/100 points.
Q: In your own words, a) explain the dynamics involved in a negative feedback loop. What is the impact of a negative feedback loop on a system? b) Describe the two examples I provided in class (one mechanical and the other in the human body). (8 points)
Good answer to the first prompt, although the mention of equilibrium is incorrect. Correctly identified both examples given in the pre-lab lecture. This student did identify one of the correct examples and gave a reasonable explanation, but the second example is missing and overall the answer lacks an understanding of feedback loops as related to things other than temperature.Did not answer the question, and the example is unrelated and shows a lack of understanding of negative feedback.
Q: We have assessed the communities pictured below for a variety of species: hawks, owls, sage brush (the round green and brown bushes), saguaro cactus, flowering cactus, jackrabbits, ravens, and foxes. For Habitat A, the species richness is 8, and Simpson’s D = 0.77. Calculate the diversity of Habitat B and answer the following questions: a) What is the species richness of Habitat B? b) What is Simpson’s D for Habitat B? c) Which habitat is more diverse? Explain your answer. (10 points)
Excellent, full-credit answer that includes calculations so I can see how this student arrived at their answer.This student received credit for prompt a, and 1 point for having begun to assess the communities, but did not do the correct calculations.Received a point for prompt a, but posted an incorrect value with no calculations shown, and did not demonstrate an understanding of the topic.
Q: Explain the difference between the two divisions of the Autonomic Nervous System. (6 points)
Full-credit responseI would have liked to see a bit more detail, but demonstrates understanding of the two systemsDid not answer the question that was asked.
Q: Explain how exercise requires changes in cellular respiration, heart, and respiration rates. (5 points)
Full credit answer with a good amount of detail.Understands the system, but I would liked a bit more detail.Again, understands the system but lacks some detail.
Q: Using the class data from the breathing lab (Table 1; page 10), in the space below, construct a scatterplot graph that shows the relationship between height and vital capacity. Make sure to label the axes, include appropriate units, and give the graph a title (10 points).
Legible and clean, and includes all necessary elementsGraphed correctly, but a bit sloppy and lacks units on axis labelsThere are some discrepancies in the data, but the graph contains all necessary elements
Q: Claudia has dimples (denoted by D). So does her father, but her mother does not. Determine their genotypes to the best of your ability. (4 points)
Failed to recognize that there is a chance the father is a heterozygoteAlso failed to recognize that the father could be a heterozygoteDid not recognize that father could be heterozygous, and also didn’t account for the fact that Claudia had to inherit the recessive allele from her mother
Q: View one of the prepared onion root slides at 400x magnification. Scan the root tip until you find a section containing cells that represent at least three different stages of mitosis. Draw a section of at least 12 cells below, including at least three different stages of mitosis (and label at least one cell from each stage). (6 points)
Excellent, full-credit illustration. Cells are at the appropriate size for this level of magnification, the labels are correct, and additional information was included (including a title, size, and magnification level)Drawing is not precise, and cells are larger than they appear that magnification. Three phases are labeled, but no other information is provided. Partial credit illustration (4 points)Student did not attempt to sketch the cells. No credit.
