For this lab, we were to design trials testing different salt concentrations on various organisms and see how they reacted to the substance we laid on them. Also, to examine at how variance in pH balances altered several organisms. Acid rain was the main center of the lab in which the effects of this rain can have colossal outcomes on the environment such as harm to forest and wildlife. Soils that are shown to acid rain can lack nutrients which leads to plants being unable to provide food for themselves. The least pH for each organism to survive at is a pH of 7. Some organisms tested though were able to still survive at a pH of 5. Anything under 5, the organisms died after only a few short minutes of exposure. We are presuming each organism to respond to the salt solution differently. With a higher salt concentration, organisms will either be more hypotonic or hypertonic.
In order to persevere, living organisms aim for homeostasis. Environmental circumstances such as temperature, oxygen level, condensation, acidity, etc can all affect an organism’s capacity to endure in a continuous state of homeostasis. For this lab, we will be examining the influence of acidity and salt concentration on existing organisms.
Acid rain is an outcome of pollution within the burning of fossil combustibles. Factories and vehicles are typically the most notable contributor to pollution and therefore acid rain. The freed nitrogen oxide and sulfur dioxide within the atmosphere responds with water and produce nitric and sulfuric acids. After some period, water precipitation joined with these acids from acid rain.
The influence of acid rain on the atmosphere produces an unbelievable amount of harm. Acid rain is breaking to plants and existing organisms similar. The raised pH level of water decreases nutrients, and hence the way plant life consumes water impact. Organisms that than depend on plant life to last will also be negatively affected. Acid rain is also toxic to marine environments. An obvious illustration of how an increase in acidity can affect marine life is the death of coral reefs. Coral reefs function as a shelter to a rich diversity of marine animals. With the increase in water temperatures and the rise in ocean acidity, corals are incapable of consuming the calcium carbonate they need to maintain their skeletal, firm structure. As a conclusion, extensive amounts of coral reefs are dissolving and ineffective of sustaining life for the organisms that lack their survival.
In addition to acid pollution, salt pollution also negatively influences the atmosphere. Climate change has provoked there to be an increasement in cold weather and snow storms. In order to face this, humans have appropriated the salting of roads and thus immediately contributing more significant amounts of salt into the environment. This development of salt in the environment is poisonous to animals and also humans; our drinking water will now carry more significant concentrations of salt and thus negatively affecting us.
We failed to reject our hypothesis for this activity. Looking at the Chlamydomonas organism beginning with a pH of 5, we remarked they were moving remarkably fast almost looking like shooting stars into the sky. As this was a neutral pH, we assumed this would be nearly a natural response for the organism. Then at a pH of 5, the Chlamydomonas began to shake and flutter but were still moving at a fast speed within the slides. Once we revealed the Chlamydomonas to a pH of 3 and 1, they quickly faded. From this, we can assume that after a pH of 5 the Chlamydomonas are incapable to live in a further acidic atmosphere. For the euglena, starting with a pH of 7, the organisms were moving swiftly through the slide. At a pH of 5, the euglena began to do this mysterious spinning movement and started to decrease the speed in which they were independently moving at beneath a pH of 7. At the pH of 3, the organisms were moving much gradual, and by the time we looked at the euglena under a pH of 1, they were hardly moving. None of the euglenas evaporated from the amount of time we spent studying at them, but I do feel that ultimately the organisms would not have remained much longer under a lower concentration of pH. For this lab, I liked how we were able to design our experiment. Something that can be arranged for next thought would be to enable us to view more organisms and under various concentrations other than just looking at pH. A source of error included that the microscope was not adjusting as well as it could have.
From this activity, we failed to reject our hypothesis. Starting with the Cladphora, we remarked that in the neutral slide where nothing was tampered with, the little green particles were all scattered in the brick-like fashion the organism is structured. Then as I observed at the 1% salt concentrated slide, the particles were now going near the edge of the bricks and away from the middle of the organism. The 5% salt concentrated slide, the particles became smaller, narrowing actually (hypertonic). By the time I looked at the 10% salt concentrated slide, the particles were shriveled entirely up and no longer as large as they looked in the neutral slide. From this, we can tell that this organism will not last under high salt concentrations. These organisms were also seen under 400x magnification, so we could get a better view of what was occurring in the organism under specific exposures. The elodea became hypotonic as we added salt to the plant. When placed under no salt concentration, the particles in the plant were small. At 1% salt concentration the elodea particle got dramatically more prominent, and the particles conformed together as one. At 5% salt concentration, the particles got even more significant, and at 10% salt concentration the particles shrunk just a tad but still were swelled up. From these conclusions, we can state that this is a freshwater plant. We also observed this organism under a 400x magnification. Some things that would be improved for this portion of the lab would be to have also more organisms to view instead of just two. It was interesting though to see them swell and shrink such as what we learned in class about hypotonic and hypertonic organisms. The similarities in these organisms though are that they both look almost similar in structure, but their intake of the salt concentrations varies. The salt concentration for a solution to be hypotonic would be at 5% and 10%. At neutral and 1% the concentration is at its lowest for it to be hypotonic in a cell. For isotonic I would say at 5% the salt concentration would need to stay around that percentage. A source of error for this portion of the lab was that the microscope was focusing on the wrong part of the organisms; therefore, some of them were a bit blurry to see.
The effects of pollutions such as acid rain cause there to be a lack of nutrients in the soil for plants to feed off of. If plants cannot be the autotrophs they are, then they are unable to provide their nutrients to animals that demand to feed off of them. If there is an increase in salts in the environment, then plant cells will either burst or shrivel up incompetent to get in H2O; therefore, we would not have oxygen to breathe in.
The importance of homeostasis is that it serves to preserve the atmosphere. If pH shifts in the atmosphere, then plants will die off which drives to animals’ incapable to graze leaving us humans do not have a food source. When homeostasis such as the earth temperature gets out of control, this can also influence the rate at which plants grow.
The euglena all died when exposed to high amounts of acidity. The closer to neutral we got in pH level, the higher the number of organisms were able to survive. The same situation applied to the Chlamydomonas. The results of this test were what we expected.
The results from our second activity reported the 1% NaCl solution to be hypotonic, so the leaf cell slightly swelled, and 5% and 10% were hypertonic, so we saw that the leaf cells shrank. Since none of our results produced an isotonic solution, we assumed that 1% NaCl concentration could be the isotopic ratio.
Since the results for the same test varied throughout the class, our group believe that there could be other variables that could have caused the variation. We believe we did not take into consideration the tonicity of the solution the elodea was kept in.
- Biology Department, Howard Community College. (2016). Lab 11: Basic Ecology. Columbia: Howard Community College. Retrieved from Bio 101 Lab.