Plant Cell | Experiment | Scientific Method

1. Graph germination rates and plant growth over time for thedifferent treatments. Also, determine the mean number of seedsgerminated and mean size or mass of the plants at the end of theexperiment. Compare average germination rates, plant growth, andhealth for the different experimental treatments. Based on yourexperiments, what was the optimal potting mix for plant germination?For plant growth? For plant health?

Efeects of Osmosis in Plant Cells - GCSE Science - …

Efeects of Osmosis in Plant Cells

Experiment: Plant Cells -- What Are the Parts of the …

One of the more influential ideas in philosophy of science is thatof robustness. Originally, the term was introduced to denote a certainproperty of theoretical models, namely insensitivity to modelingassumptions. A robust result in theoretical modeling is a result thatis invariant with respect to variations in modeling assumptions (Levins1966; Wimsatt 1981; Weisberg 2006). In experimental science, the termmeans something else, namely that a result is invariant with respect tothe use of different experimental methods. Robust experimental resultsare results that somehow agree even although they have been produced byindependent methods. The independence of methods means two things:First, the methods use different physical processes. For example, alight microscope and a (transmission) electron microscope areindependent methods in this sense; the former uses visible light, thelatter an electron beam to gather information about biologicalstructures. The second sense of independence concerns the theoreticalassumptions used to analyze and interpret the data (most data aretheory-dependent). If these assumptions are different for the twomethods, they are also referred to as independent, or as independentlytheory-dependent (Culp 1995). These two senses of “independent” usuallycoincide, although there could be exceptions.

Experiment: Plant Cells -- What Are the Parts of the Onion Skin Cell?

On what grounds was this selection made? And who made it? A simple,but perhaps incomplete explanation is that the Morgan approach togenetics was selected because it was the most fruitful. A skilledgeneticist who adopted the Morgan way was almost guaranteed to come upwith publishable results, mostly in the form of genetic maps, andperhaps also some interesting observations such as mutations thatbehaved oddly in genetic crosses. By contrast, the alternativeapproaches that were still around in the early 20th Centurydid not prove to be as fruitful. That is, they did not produce acomparable number of results that could be deemed a success accordingto these sciences’ own standards. What is more, thealternative genetic approaches were not adaptable to other scientificdisciplines such as evolutionary biology. Classical genetics thusout-competed the other approaches by its sheer productivity, which wasmanifested by published research papers, successful grant applications,successful students, and so on. It was therefore the scientificcommunity as a whole that selected the new genetics due to itsfruitfulness. At no point was there any weighing of evidence for oragainst the theoretical framework in question on the part of individualscientists, or at least this played no role (of course, there wasweighing of evidence for more specific claims made within the sameframework). Theories in experimental biology are thus selected as partsof experimental practices (or experimental systems, see ),and always at the community level. This is how a social epistemologicalaccount of scientific change in experimental biology might look like(Weber 2011).

What happens to plant cells in hypertonic and hypotonic solutions

The last two sections have treated experiments primarily as ways oftesting theoretical hypotheses and causal claims, which is wheretraditional philosophy of science saw their principal role. However,there exists a considerable body of scholarship in the history andphilosophy of biology that shows that this does not exhaust the role ofexperiments in biology. Experimentation, to echo Ian Hacking's famousslogan, “has a life of its own” (Hacking 1983). Much that goes on in abiological laboratory does not have the goal of testing a preconceivedtheory. For example, many experiments play an exploratoryrole, that is, they assist scientists in discovering new phenomenaabout which they may not yet have any theoretical account or not evenany clear ideas. Exploratory experimentation has been investigated inthe history and philosophy of physics (Steinle 1997) as well as biology(Burian 1997, 2007; Elliott 2007; O'Malley 2007; Waters 2007). Thesestudies show that the development of any discipline in experimentalbiology cannot be understood by focusing on theories and attempts toconfirm or refute these theories. Experimental practice is simply notorganized around theories, particularly not in biology. If this is so,we must ask in what other terms this practice can be explained orreconstructed. Recent scholarship has focused in particular on twokinds of entities: model organisms and experimentalsystems.

Purpose: Students will observe plant cells using a light microscope

A variant of IBE is also used by Cresto (2008) to reconstruct theexperiment by Avery that showed that the transforming principle inpneumococcus is DNA rather than protein. However, her conclusion isthat, in this case, IBE is inconclusive. What it does show is thatthere was a rational disagreement, at the time, on the question ofwhether DNA was the transforming principle.

LabBench Activity Plant Pigments and Photosynthesis

Even though this really looked like a spectacular confirmation ofthe semi-conservative scheme, Meselson and Stahl (1958) were quitecautious in stating their conclusions. Avoiding theoreticalinterpretation, all the experiment showed was that base nitrogendistributes evenly during replication. While this is inconsistent withthe dispersive mechanism, it did not rule out the conservativemechanism. For it was possible that the material of intermediatedensity that the ultracentrifuge's optical devices picked up did notconsist of hybrid heavy/light DNA molecules at all, but of some kind ofcomplex of heavy and light DNA. For example, Meselson and Stahlspeculated that end-to-end covalent associations of old and newlysynthesized DNA that was produced by the conservative mechanism wouldalso have intermediate density and therefore produce the same band intheir experiment. For this reason, the experiment does not reallyqualify as a severe test of the semi-conservative hypothesis in thesense of the error-statistical approach. For a severe test must ruleout, with a high probability, the passing of a hypothesis even if it isfalse (see ). If the intermediate bands observed byMeselson and Stahl were end-to-end covalent complexes produced by theconservative mechanism, then the experiment would pass thesemi-conservative hypothesis even though it was false. There is nothingin the experiment that would rule this out with high probability,therefore it was not a severe test.