Qualification > Sciences
Edexcel BIOLOGY Doubts!!!!
Uchia:
help me in the following questions please
1) list 3 precaution which would be needed when doing the vit c experiment
i know two of them 1) conq and volume of DCPIP 2) same conq of vit c by using same solution
2) give 2 ways other than boiling which vit c could be lost?
I know 1) leaving it exposed to air
3)Callus tissue develops into either shoots or roots depending on the relative concentration of the plant
growth regulators used. Use your knowledge of genes to suggest how these plant growth regulators
determine the type of plant tissue formed.
last
could you tell how to ensure the reliabilities when doing the experiments such as betroot, vit c, tensile strength, mitosis, etc...
M-H:
--- Quote from: damlaj on May 10, 2010, 09:36:46 am ---help me in the following questions please
1) list 3 precaution which would be needed when doing the vit c experiment
i know two of them 1) conq and volume of DCPIP 2) same conq of vit c by using same solution
2) give 2 ways other than boiling which vit c could be lost?
I know 1) leaving it exposed to air
3)Callus tissue develops into either shoots or roots depending on the relative concentration of the plant
growth regulators used. Use your knowledge of genes to suggest how these plant growth regulators
determine the type of plant tissue formed.
last
could you tell how to ensure the reliabilities when doing the experiments such as betroot, vit c, tensile strength, mitosis, etc...
--- End quote ---
juice is expired...vit c content will b less
reliability-beetroot...um, all the beetroot discs gta b of same size surface area thickness
volume of distiled water in wich theyr kept needs to b the same
if the experiment is done to see the effect of conc of alcohol-the temp needs to be fixed.
Vit. C-
conc. and volume of DCPIP needs to b kept constant
once a glassware-pipette/burette used, if it has to be used again then it needs to be washed before used and then the solution can be taken in it.
mitosis-
all root tips nearly of same size
making sure the nucleus is stained and not the cytoplasm.this' done by placing the slide on the tissue paper, fold the tissue over and gently press so that all the stain is absorbed.
that's all i can think of for now....ur 3rd question..um i don't know much..i can guess but don't wana say unless im v sure.
hope that helps
:)good luck...
wrongaccount:
I dont understand the flow chat things ): ):
for instance in JAN 2010 Q2 part a) how am i suppose to draw that flow chart ??
and if there is any other flow charts in previous papers please let me know
Uchia:
for the flow charts its easy you just need first to know how the experiemnt is done for example in jan
the question was about weithering before you draw the flow charts you should already study what he did cz its included in the syllabus and i think you will find it in how science works in your text book
Flow charts
1) start 2) reasearch, gathering information and compare 3) test drug on small number of healthy people 3) record effects 4) see if there is death 5) test on small number of people with disease 6) record effects 7) increase/decrease the dose of the drug 8) record effects and compare to find the appropriate dose 9) approval and sale
Assi1993:
Suggest why Daphnia needs a heart and circulatory system
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