FAQ

1 Question – How to Study

This question was asked by 3rd years, but it is relevant here too.

I just need some advice from sir. I’m starting to study today and I just wanted to know what do you think is the best way to study for sir’s exam. I’m asking because I studied really hard for the midterm tests but I still got low marks lol. So I just wanted to know if there is maybe a different approach that I can take.

I was trying to memorise things for the midterm tests but I know sir said we must focus on understanding but when I focus on understanding then the work does not stick in my head😂.

So far I’ve just read through the articles but is there any advice that sir can give me please?

1.1 Answer

Thank you for your email. Hmmm, a tricky question to ask of someone who wrote their last exam in 1993!

I am the opposite to you. I cannot memorise things but I am able to understand things really well. Fortunately, in the process of figuring things out, the relevant bits of information/knowledge relating to the thing I am trying to understand also sticks in my mind, which is (for me) a useful side effect of figuring things out. For me, it is pointless having things to memorise unless I can apply it to something that needs figuring out. So, everything I know, I know because it is useful to me.

How does understanding come about? For me, I try and understand stuff because the challenge of a tricky problem is thrilling, so understanding is facilitated because the process aligns with what makes me ‘tick.’ Okay, so this does not answer how understanding comes about; it simply talks to who I am.

I can tell you is how you can test your understanding. Explain the thing you are trying to understand to a friend or family member. If your explanation of the topic brings about an understanding in the other person, then you yourself understand it. At least this process will tell you where your own understanding starts to fail. As Richard Feynman said, “If you cannot explain something to a 7-year old, you don’t understand it yourself.” Or something like that.

For someone who finds it easier to memorise stuff and more challenging to understand… I don’t know what that feels like as I have no personal experience or frame of reference that allows me to place myself into your shoes. But here is the theory:

  1. Know what it is you already know, and build upon that (see point 2).

  2. Structure new and existing knowledge around the major concepts and principles of the module (broadly, the new concepts covered each week). This means that work done in your first and second years of your study, in ALL the modules you completed, remains relevant, and has to be used together with the new knowledge obtained in the new module, and structured around the broad concept and principle (there are many concepts and principles a module).

  3. You need to develop and understand the language used to communicate the topic. At the very basic level, this requires that you understand in intricate detail the individual words (ALL of them) that form the foundational language of your study discipline (biology and science more broadly). Only once you understand the definitions of individual words will you be able to develop more complex understanding. I think this is the primary reason why students fail to develop a deep understanding of a topic that requires explanation in multiple paragraphs (long answers and essays).

  4. Another step involves knowing how all the steps that inform the thinking process are interrelated. This requires that you consider some of the following things: What does the assignment or task require me to do (i.e. unpack the problem)? What are the steps I need to follow to get there? What do I already know about it? What do I not understand and where do I get stuck? Why don’t I know it already? What about the problem causes me to get stuck? Where do I get the knowledge about what I don’t understand, and how can I use this to become unstuck? Okay, so now I am figuring things out… What does the problem remind me about? Have I encountered something similar before, and if so, how can I use that to develop further my current thinking about the problem? This whole process is called metacognition, which is thinking about thinking and learning. This kind of thing has to happen each time you see something new, come across a new piece of information, listen to someone speak, etc. It can be applied in your day to day life to the extent that it become implicit in how you approach life. Eventually, you’ll find yourself saying more often, “I am wondering…” Then you will arrive at critical thinking, which is what makes science special.

  5. How well you are able to integrate the metacognitive skills in your life and learning depends unfortunately on your inherent abilities and prior experiences. It is easier for some than it is for others.

  6. A critical characteristic of good learning is that it informs your sense of self — this means that once you value learning as one of the things most important things (attributes) which informs who you are as a person, the easier it will become to learn, the less effort it will take, and the more learning itself will become the motivator (as opposed to search for motivation externally, like some reward, for having to learn).

  7. The activities in your life, your friends, family and interests will also shape how much you learn, and what you learn.

  8. You need to mix with people who values learning to the same extent that you do, so this social reinforcement further ‘snowballs’ into life-long learning and understanding.

Step no. 4. is probably to most helpful.

2 What are climatic envelopes?

Good day sir, there isn’t a good definition of climatic envelopes on google. Sir spoke about it in consequences in climate change. Not really sure what it specifically is.

2.1 Answer

Climatic envelopes are the suite of environmental conditions required for plant (or animal) growth that define the optimal niche area and hence the organism’s distribution.

One can model the future climatic envelopes using various statistical approaches, and hence so project the future distribution of the species (or ecosystems) whose distribution are linked to those envelopes. Such models are called bioclimatic models or niche models.

The process is called species distribution modelling. We will do this in Hons.

Enough? The first little para I wrote is the definition and all you would put down if I asked.

3 Question About Acclimatisation

I also wanted to ask. When plants avoid stress, is it not acclimatization as well?

3.1 Answer

Yes. But there’s only a certain range of env conditions plants can acclimatise to, and exceeding those limits will still cause stress.

Acclimatisation can happen over minutes to hours to days. Or seasonally. But if env conditions exceed the normal range of variability they’ll become stressed.

4 The Essay

4.1 Question About the Organic Foods Essay Topic

I chose the organic food topic. My question is if I should find research papers for everything I state?

E.g “Organic food has been a growing interest as people have become more concerned about their diet and what they chose to consume.”

Do I need to search an article to support that or can I leave it as is since it’s something I’ve recently seen with friends, family and on social media platforms (how organic food is the “right food” to consume).

Answer

I think it’s commonly knowledge based on lived experience that organic foods have become more widely consumed. So no need to ref that. But the claims that people make about why organic foods are ‘better’ often do not have factual support. So, if you state that it’s better for whatever reason, that needs factual support. If no support is available, your conclusion would have to be that the claim is dogma, i.e., untested, unsubstantiated, wishful thinking, etc.

Scientific studies need to be done in order to prove some hypothesis. Without it the claim remains unsubstantiated despite how many people buy into the claim. Simply because 10 million people think it is good does not actually provide any evidence that the claim is fact.

5 Light, pigments, and photosynthesis

5.1 Question About Pigments

Good day sir, I have a question about accessory pigments. I know they help pass light onto chlorophyll-a for photosynthesis right? And different chlorophylls, especially chlorophyll-a bind to proteins in different ways. Is that in order to absorb more more that the chrolophyll pigment itself wouldn’t be able to absorb?

Answer

“different chlorophylls, especially chlorophyll-a bind to proteins in different ways. Is that in order to absorb more more that the chlorophyll pigment itself wouldn’t be able to absorb” — No. If one would have to design something, then that would be the approach. But these molecules were not designed. They evolved. Evolution does not work by something functioning in a specific way in order for some other thing to do what it does. The specific protein binding between the pigments and proteins happened because, by chance, some configuration arose that happened to fill some need, that is, to fill the green gap. It happened by chance, not design.

6 The Nitrogen Cycle

6.1 Question About Eutrophication

Good day Professor, I was wondering if sir could clarify something. Is an anoxic water where there is no dissolve oxygen? And is that caused by oxygen-using bacteria that decompose dead organisms in eutrophic environments?

Answer

Not no oxygen. But very little. Usually anoxia is reached at O2 concentrations below 2mg/L. Before that low level it’s called hypoxia.

Yes. It is caused by bacterial respiration. Hypoxia/anoxia causes even more species to die, and further reduces O2 concentrations.

Eutrophic conditions can cause biomass accumulation of photoautotrophs. During night extremely dense biomass of such accumulations don’t photosynthesise but continue to respire. This is when low O2 first starts, and it causes the initial die-off.

6.2 Question About Biofouling

Hi Professor is biofouling and epiphytes the same or different things?

Answer

Biofouling is a process. It’s the process by which epiphytes colonise the surface of a basiphyte. The epiphytes in question might be macroalgae, but it’s most typically microalgae or bacteria (the latter two collectively called biofilm).

6.3 Question About Calculating the Rate of Uptake, V

Good day Professor, I am hoping sir could assist with my work. For the V column, does that represent the rate that N is being assimilated into the thallas? If so, then the values should be positive right? 😅.

I’m asking because some students are getting negative values. Regards

Professors response.

“Yes. Why do you think there’s a negative value? What does a negative rate mean—i.e. does it apply to the culture medium (where the concentration decreases) or to the seaweed (where it increases)?”

I believe the values of the slope are negative because that shows the rate of N that leaves the solution. If I can put it like that

Answer

Yes! And thus the rate of appearance of N in the seaweed is of the opposite sign, so simply take the absolute value.

6.4 Question About Calculating S in the Nutrient Uptake Experiments

Sir, do we consider the only culture volume when calculate our S (substrate conc)? and we use μmol N or μg N units or it doesn’t much matter

Answer

It is a function not so much of culture volume, but of the amount (micro moles or micrograms) of nutrients within a volume of seawater.

Volume per se is not important: the concentration of a substance is the same in 1 ml or in 1 liter. The amount (moles or grams) of a substance is very different in that 1 ml or 1 liter, however. So, volume does not affect concentration, but it affect total amounts available in a volume.

6.5 Question About Perturtbation Experiments

(AJ?) Smit professor, with multiple flask experiment you said you can calculate update rate (so I’m assuming it’s a linear graph) and with perturbation you said it’s a depletion curve.

With the Michaelis- menten we measure substrate concentration against uptake rate but use perturbation methods (using the gradient for the uptake rate) Since multiple flask also shows uptake rate can you still use this methodology to generate a Michaelis-menten expression? Also wouldn’t it have been easier because then you don’t have the whole x-axis confusion

Answer

WhatsApp Ptt 2022-10-12 at 10.25.49 PM.ogg

6.6 Question About Ks and \alpha

With regards to Michaelis Menton expression and specifically the Ks and \alpha does that specifically relate to diffusion ability?

Does a high Ks mean diffusion was rate limiting sooner whereas a low Ks meaning kinetics was rate limiting?

Or am I completely misunderstanding the work?

Answer

Yes. Ks and \alpha relate to the externally controlled phases of nutrient uptake, so they are controlled by diffusion (and thus also water motion and nutrient concentration).

6.7 Question – The Nitrogen Cycle

I just wanted some clarification, is it correct to say that the definition of the nitrogen cycle is a biogeochemical process through which nitrogen is converted into many chemical forms circulating in the marine, terrestrial and atmospheric ecosystems?

Answer

N cycle. I’d say something like this:

The uptake, transformation, release, and transport of N-containing compounds through components of the Earth system, including the biosphere, geosphere, hydrosphere, cryosphere, and atmosphere. The underlying processes involve a series of biologically, physically, and chemically mediated processes which act on different compounds of inorganic and organic N.

More simply we can say the N cycle is N biogeochemistry, but less is explained by this short statement than by the longer one.

7 Question – WhatsApp Ptt 2022-11-13 at 9.43.54 AM.ogg

7.1 Answer

Very nice question! It is a pity I already set the exams.

So why does Ulva not show saturation at some point?

Within the range of N concentrations typically present in the ocean, say up to 20μM N in upwelling systems, uptake should (can) theoretically remain unsaturated, PROVIDED THAT ALL OTHER ENVIRONMENTAL CONDITIONS REMAIN OPTIMAL. There always has to be sufficient amounts of light; the temperature must be optimal, and so on. As soon as the GROWTH RATE slows down because the alga cannot capture enough light to drive photosynthesis (for cellular replication and biomass growth), there will be an upper limit to the amount of N taken up sequestered. So, the high uptake rates promised by a fully rate-unsaturated uptake mechanism supported by diffusion are only possible if the alga can produce enough biomass quickly so it can assimilate N into biomass (protein). Algae can only assimilate N if enough C comes in (through photosynthesis) for sufficient amounts of the C compounds containing N in an organic form.

Therefore, all suboptimal environmental conditions influencing C uptake will affect N uptake.

Only some environmental conditions are optimal for long enough for algae to sustain high N uptake through rapid growth rates. Only because of fast growth rates will N be maintained at low enough concentrations in the vacuoles to prevent feedback inhibition. When feedback inhibition happens, the rate of N uptake is limited. Under most natural conditions, there is likely an upper limit to N uptake. However, we can create optimised conditions in the lab to maximise the algal growth rate; thus, N uptake could remain unsaturated.

Even passive uptake (N uptake through diffusion) can be rate limited if the amount of N building up inside the cells is so high that it reduces the concentration gradient across the cell from outside (water) to inside (vacuole). In this situation, there would also be a Vmax, determined by the rate at which the alga can bind N into an inorganic form, typically as protein (including some phycobilins).

8 Question – Question About a Question

Sir with this, are we actually supposed to draw the graphs and do the calculations or simply state what needs to be done?

The question about which the question is asked.

8.1 Answer

It’s as the question says:

Design an experiment that will provide insight into both the optimum ratio of N and P and the optimum concentration of potassium nitrate and orthophosphoric acid to feed the U. lactuca mass culture (i.e. with the aim to maximise biomass production).

In your answer, please pay specific attention to the experimental conditions during the acclimation phase (i.e. a period lasting two weeks prior to the experiment), as well as during the experimental phase. Provide a rationale and justification for all your decisions that ultimately inform your experiment.

Calculations can only done after the experiment is completed, and the question simply asks that you design the experiment.

9 Question – The Anthropocene

Just a quick question to anyone who might know the answer: Based on Rockstrom’s paper, especially the intro, in which period are we currently? He first mentioned the Holocene, but then states that we have entered the Anthropocene. However, a few sentences later he talks about maintaining the the status and staying in the Holocene.

9.1 Answer

The American Geophysical Union does not recognise the Anthropocene as an actual geological epoch yet, so according to them we are still in the Holocene. But many people think that we have already deviated so far away from what was typical for Holocene into something very different, and that we should redefine the current era as the Anthropocene.

What’s your personal view Prof?

Anthropocene means ‘the age of humans’. So, humans have become so abundant that the signal of our activities have made an imprint on global biogeochemical systems such that in millennia from now when people no longer exist, ‘we’ (whatever replaces us or visits Earth) will be able to pick up signs of people’s existence in various geological strata on Earth.

I think it makes sense to call where we are presently the Anthropocene, and I think Johan Rockström makes the same argument.

10 Question - Conclusions Drawn from the Keeling Curve

Can we also use Keelings conclusion to justify that we are in anthropocene because I think it goes hand in with what John [Johan Rockström] is saying?

10.1 Answer

Ralph Keeling’s work is part of the justification. Much more has happened since, especially in the last decade. I don’t think a justification to use Anthropocene yet existed in the 1960s, but there’s plenty going on now to cause one to make that argument.

See The Keeling Curve for nice views into what constitutes the Keeling curve over various timescales.

11 Question – About the History of Climate Change

Good day Prof for the key historical events with regards of climate change do we have to know the years or would the persons name and what they discovered be enough for an answer?

11.1 Answer

I guess I’m not so much interested in exact dates, but do knowing which part of which century things happened is important. And the correct order of events. The fact is, we know about climate change far longer than people give credit to.

12 Question – Question About a Previous Exam Question

Sir, I’ve been struggling to contextualize the Guideline you gave us on Material and Methods.

I saw a question on a previous question and I struggled to answer it for 25 marks.

The offending question.

12.1 Answer

I gave you the answer on Friday [the one about N uptake, as seen above]. Something like that. Just adapt it for photosynthesis. You want to measure O2 production/consumption or CO2 production/consumption in stead of nutrients.

Just pick your favourite plant or algal species. The experiment must be appropriate for plants or algae, of course. The difference is that plants live in air and algae in an aqueous medium, so the experiment must be set up appropriately.

In air we use an IRGA (infrared gas analyser) and in water we can use an O2 meter. Or we can use a C14-labelled source of CO2 and use scintillation counting to measure the appearance of a radioactive C for in the pool where CO2 accumulates.

Otherwise, not too different from the N uptake answer, except we probably won’t use the perturbation method.

And you probably want to measure net photosynthesis, so make sure you measure respiration too.

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@online{j._smit,
  author = {J. Smit, Albertus},
  title = {FAQ},
  url = {http://tangledbank.netlify.app/BDC223/BDC223_FAQ.html},
  langid = {en}
}
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