1st hand investigation-phenotype (1 Viewer)

[Cherry_blossom]

argh!
I have to do a first hand investigation demonstrating the effect of environment on phenotype! but i have no idea how to go about it
I have looked up on the net and in my textbook but i can't find any guides about doing the investigation.
please help!
how many environmental conditions should i test? and how many times should i repeat the experiment?
The only environmental feature that may produce some results that i can actually see would be light.
but i have no idea about how to go about it
any suggestions?
thanks

 

[elisabeth]

OK, just finished doing this. Pretty simply, we put 50 wheat seeds (fast growing) each tray, put one in complete darkness, one outside and one in a hot house, ie. partial shade. measured them and wrote it up.

BUT there were a lot of different reasons why its hard to get accurate results. I suggest doing something with fertiliser (ie. do various levels of NPK soil have an effect on height of wheat plants?) because it's easier to control.

If you want, when you've done yours I can email you my report to compare.

 

[elisabeth]

Oh, and:

"how many environmental conditions should i test? and how many times should i repeat the experiment?"

You're only testing the effect of ONE variable. If you do the type of experiment I described, you won't have time for repeats... we did it over a month.

 

[*sarah*]

You can do a quicker one over a few days using sprouts - put equal numbers of seeds on equal amounts of cotton wool in light/ dark and compare them - v simple but...

 

[malkin86]

The search function on BoS is your friend...

http://www.boredofstudies.org/community/search.php?searchid=267032

 

[Cherry_blossom]

OK, just finished doing this. Pretty simply, we put 50 wheat seeds (fast growing) each tray, put one in complete darkness, one outside and one in a hot house, ie. partial shade. measured them and wrote it up.

BUT there were a lot of different reasons why its hard to get accurate results. I suggest doing something with fertiliser (ie. do various levels of NPK soil have an effect on height of wheat plants?) because it's easier to control.

If you want, when you've done yours I can email you my report to compare.

so did you have 3 trays each containing 50 wheat seeds. put one tray in complete darkness, one outside (is that the control?) and one in a hot house?
is that testing the effect of light on the phenotype of the plant?

thank you for your help much appreciated

 

[elisabeth]

Yep.

The only thing is, i really reccommend you do fertiliser or something else. for a number of reasons, our experiment was fucked:

- can't control temperature (it was a couple of degrees cooler in the hot house)
- higher humidity in hot house
- plants outside got more water when it rained

those are just some examples of how it's hard to control the variables.

with fertiliser, you just put a bit in one, a bit more in another, lots in one and none in another. or so i presume. then you can put them in the same location and not have to worry about the differene in the other environmental factors, as above.

also - when you're measuring the wheat sprouts, don't just measure the tallest in each (could be an anomaly), measure some short, some tall and some medium. or all of them and do an average.

good luck with it. btw, when are you planning on doing this? only one day of term left...

 

[elisabeth]

The search function on BoS is your friend...

http://www.boredofstudies.org/community/search.php?searchid=267032

"Sorry - no matches. Please try some different terms."

 

[MaryTylerMoore]

Hey,

I think you should just put all plants in the same size pot, with the same potting mix, same nutrient additions, same amount and type of water, same seeds in the same location (i.e. window sill let's say so the temperature and amount of light available etc. all stay the same) but you put one in complete darkness by putting something over it, another is partly shaded off from direct sunlight (like stop light hitting the plant directly) and then another has complete light from the sun in it's window position. Then use plant height as an indicator. Alternatively, you could use different concentrations of salt in the water and see what effect salt has on plant growth.