Understanding Salmonella: Natural Selection and Trait Variations
School
Bear Creek High School**We aren't endorsed by this school
Course
SCIENCE 1A
Subject
Biology
Date
Dec 9, 2024
Pages
5
Uploaded by MagistrateEnergyKookabura44
Salmonella InvestigationEssential Question:How well does our General Model predict and explain the changes happening over time in a different population?Part A: Simulating a Neutrophil in the Environmenthttps://www.openscied.org/general/salmonella-hunt/A.Make sure the simulation has the following settings: Auto-stop: at time = 1000Time = 0Initial bacteria per variation = 5Visualize variation = flagella onlyB.Input your selections for the simulation by clickingon setup. Start the simulation by clicking ongo/pause.C.Hunt bacteria by chasing them aroundand clicking on them. D.When the simulation automatically stops, compare your results with your table group. 1.What happened to the distribution of trait variations in your populations?a.The bacteria population with flagella became dominant over time. The bacteria without effective traits for mobility were caught and eliminated more quickly, causing the trait variation with flagella to increase in frequency.2.Why might you and your table group have seen similar shifts in the distribution of trait variations but not exactly the same results?a.Small differences in how we hunted bacteria or random movements of the bacteria in the environment could result in slightly different outcomes, even though the overall trend toward certain trait dominance remained consistent.3.How did the population change in this environment?a.The overall population decreased as bacteria were hunted, but those with advantageous traits like flagella survived longer and reproduced, shifting the population to favor this trait.4.Why did the population change in this way?
a.Natural selection occurred and those with traits that allowed them to evade capture (e.g., flagella) survived and passed on their traits, while those without advantageous traits were eliminated.
Part B: Simulating a Monocyte in the Environment E.Make sure the simulation has the following settings: a.Auto-stop: at time = 1000b.Time = 0c.Initial bacteria per variation = 5d.Visualize variation = flagella onlyF.Input your selections for the simulation by clicking on setup. Start the simulation by clicking on go/pause.G.Hunt bacteria by leaving your mouse in one part of the environmentand clicking the bacteria when they come under it.H.When the simulation automatically stops, compare your results with your table group. Discuss the following questions and record your answers below:5.What happened to the distribution of trait variations in your populations?a.The bacteria population with more mobility, such as those with flagella, became more prevalent as they could escape hunting, which was slower to hunt.6.Why might you and your table group have seen similar shifts in the distribution of trait variations but not exactly the same results?a.Differences in bacteria movements or clicking speed during hunting can cause slight variations in results, even though the overall shift in population traits is similar.7.At the start of the model run there were 6 different trait variations in your bacteria population. With your table group, compare how many different trait variations there are in each of your populations now.a.The number of trait variations likely decreased, as the bacteria with less advantageous traits (such as those without flagella) were hunted more easily andeliminated, leaving fewer variations in the population.I.Adjust the time setting to 4000. Click on go/pause.J.Leave your mouse cursor in one part of the environmentand click when bacteria run into your cursor.8.Did the number of trait variations in the population remain stable or did it change?a.The number of trait variations changed, with certain traits (like flagella) becoming more common and others being reduced or eliminated.
9.Do you think bacteria with a different number of flagella might have a competitive advantage for surviving or reproducing in environments that have different amounts or distribution of these sorts of resources in them? Why?a.Yes, bacteria with more flagella would likely have a competitive advantage in environments that require rapid movement to escape predators or access resources, as increased mobility would enhance their survival and reproduction chances.
Part 3: Individual ReflectionNow consider whether our General Model could be used to explain some things about penguins. Penguins spend about 75% of their lives in the water. Some penguins can swim much faster than the fastest human swimmer. On land, however, all penguins move much slower thanhumans. 10. How could variations in some of these (or other) heritable traits give some individuals a competitive advantage over others in the water? How much that affect their chances of surviving or reproducing?a.Variations in heritable traits can significantly impact penguins' survival and reproductive success in water. Traits like streamlined bodies, efficient flippers, and better fat reserves enhance swimming speed and foraging effectiveness, while coloration helps avoid predators. These adaptations increase the chances of escaping threats and securing food, ultimately improving individual fitness.11. How could variations in some of these (or other) heritable traits give some individuals a competitive advantage over others on land? How might that affect their chances of surviving or reproducing?a.On land, traits that improve walking efficiency, nesting strategies, social behaviors, and thermoregulation also play crucial roles in survival and breeding success. Penguins that can move more quickly, choose safer nesting sites, and regulate body temperature effectively are more likely to thrive in varying conditions. Together, these advantageous traits contribute to overall fitness, allowing natural selection to shape populations in response to environmental challenges.