[Spud93]

Laboratory experiments such as this allow researchers to measure
photosynthesis and respiration in organisms under highly controlled
conditions. For example, in this experiment the temperature was maintained
at 18 °C.
Suggest why the temperature was kept constant and what effects there may
have been on a test sample if the temperature had increased or decreased by a
few degrees during the experiment. (100–150 words)

(d) The number of moles of oxygen produced/consumed in the experiment
described in Table 1 can be related to the amount of energy stored or released
by the phytoplankton. If you assume that one mole of oxygen is equivalent to
500 kJ (3 sig figs) of energy, convert the values in Table 1 into units of
energy stored/released per hour, and display your answer as a new table.
(Hint: the energy for the first species Amphidinium carterae has been
calculated for you in Table 2 below. Calculate the energy for the other two
species, showing your working, then construct a new table to display the
results for all three species.)Table 2 Energy stored/released per hour.
Species of Conditions Rate of change in oxygen Energy/kJ h−1
phytoplankton light concentration/μmol O2 h−1 0.0131
Amphidinium carterae dark 26.2
−7.50 −0.00375

(e) Using the experimental data shown in Table 1 for Amphidinium carterae
calculate what percentage of the total energy assimilated in light conditions
in 1 hour is used for respiration in this organism. Show your working clearly
and give your answer to the appropriate number of significant figures. (Hint:
you will need to use the data from the dark condition as well as the light
condition in your calculation.)

(f) In recent years phytoplankton have been investigated as a potential source of
energy for humans. Researchers have therefore been interested in whether
these organisms could be 'farmed' to provide food or fuel. In terms of
biomass, Gross Primary Production (GPP) in phytoplankton living in a layer
just below the surface of a typical ocean area is 4102 g m−2 yr−1 If you .
assume the energy value of phytoplankton is 6 kJ g−1 ,calculate the GPP in
terms of kJ m−2 yr−1 .Show your working clearly .

(g) If a human needs to eat about 10 000 kJ per day, estimate (to the nearest
gram) the mass of phytoplankton that would be required to meet their daily
energy requirements. Based on this value, approximately what proportion of
her own body weight in phytoplankton would a 60 kg woman need to eat
over the course of a year, if this were her only source of energy? Show your
working clearly.

(h) Farming phytoplankton to harness solar energy for human food or fuel would
presumably require cultivating large numbers of these organisms in a
carefully designed artificial environment. Suggest two features that could be
incorporated into the design of a phytoplankton 'farm' to optimise the Net
Primary Production (NPP). Briefly describe why each design feature would
be useful. (One sentence for each)

[Curlyben]

Thank you for taking the time to copy your homework to AMHD.
Please refer to this announcement: https://www.askmehelpdesk.com/financ...-b-u-font.html

[Unknown008]

You've been here for some time now and should know that you have to post your attempt at the question first, and all those numbers are meant for you to do, not us... =/

[Spud93]

(f) I'd be thinking something like this: you need an answer in energy (kilojoules) per metre per year. So if you take the GPP by weight (per gram), per metre, per year and multiply it by the amount of energy created by that weight of biomass, you'll get your answer.

(g) So you know the energy produced by the biomass per gram. And you know how much energy you need. You divide the total energy needed per day, by the amount of energy produced per gram, per day and you have an answer.

(h) What do phytoplankton need to survive and thrive? Well, you can look this up, but they need to be near the surface of the water, so that suggest a feature for your design. They need sunlight or maybe the right type of artificial light and you also need to be able to harvest the results. So you can get an idea from this for design. This as far as I've got could you tell me if I'm heading in the right direction pleas

[Unknown008]

(f) Correct.

(g) Not quite. You only need one more step. After you get the value you got, you need to find the proportion of her weight which equals that mass of plankton.

(h) Good, but you can also add more. This wiki article might help you a lot:

Phytoplankton - Wikipedia, the free encyclopedia

[AlisonD]

@spud: This is a direct copy of a question from the Open University S104 TMA05, and you are cheating. Shame on you - lots of people are working very hard to get this qualification and you have been reported to Student Services. Do your own work in future.

[Narcoman]

@spud. This is word for word a question that is part of a Open university science module S104 TMA05. You are cheating. You should be ashamed of yourself. Only wish we had your real name so you could be outed to your Open University Fellow students who are working to get to obtain this qualification using there own intelligence and ability

[kraftykitten]

This is an Open University science S104 module question and I agree that you should be ashamed of yourself as it is cheating. You should contact your Tutor if you need help or read the material that has been given to you. You are not going to learn anything if you continue to cheat and I agree that you should be outed to your Open University Fellow students who are working to through learning to obtain their qualification.

[jaymat]

Can anyone just run through g) for me please, I don't want the answer but I would like to know if I'm on the right track. Do you need to use the value from f) to answer g)?
I have started by dividing the value needed per day from the energy value which I think gives me the mass in grams?
Then do I use the answer from f) to work out the mass needed to feed 60kg? (ie multiplying until I get to 60kg?)

[Unknown008]

f) GPP = 4102 g/(m^2 yr)

GPP = ? KJ/(m^2 yr)

So, only thing that changes is g to kJ. You are told that 1 g -> 6 kJ
How much kJ would 4102 g produce? That's what it's asking.

g) 1 person needs 10 000 kJ a day.
1 g of phytoplankton represents 6 kJ

Work out the mass of phytoplankton.

Now, work out that mass over a year, and find the relationship in terms of percentage with the mass of 60 kg given.

[madmoo]

Tut tut spud you have even pinched this from somebody else...
https://tutorhub.com/question/phytoplankton-biology-project-help-me-pleas
Mate the rest of ask are also really struggling with S104 but I think this is definitely classed as cheating. This is what your tutor is for!!