What do we have to study for Biology unit 3???!! There is nothing to study for it... ??? ??? ???
What do we have to study for Biology unit 3???!! There is nothing to study for it... ??? ??? ???All the practicals in unit 1 and 2
I have this question regarding Beetroot pigments..
Suggest why it was necessary to rinse the beetroot discs before they were added to the distilled water.
I have this question regarding Beetroot pigments..to wash away excess dye
Suggest why it was necessary to rinse the beetroot discs before they were added to the distilled water.
i need HELP in some exp's.https://studentforums.biz/index.php/topic,4830.0.html
1-totipotancy in plant cells
2-viewing mitosis
"i don't know how should i write them in the exam"
??? :(
help me in the following questions pleasejuice is expired...vit c content will b less
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...
All the practicals in unit 1 and 2
-daphnia's experiment
-cell permeability experiment
-vitamin c experiment
-enzyme controlled reactions experiments
-root tip squash experiment (observing mitosis)
-investigating totipotency in plants (tissue culture)
-mineral ions deficiency experiment
-antimicorbial properties of plants experiment
- plant fibres experiment
thats all
and some background of some unit 1 information such as CVDS and their risks, Genetic diseases (like CF) and genetic diagrams, what else..
genetic screening
(scan through)
for unit 2, basically you're taking the exam now in june so you know the information/facts there..
Suggest why Daphnia needs a heart and circulatory systemI think so it can be able to pump the blood around the circulatory system so the person testing on daphnia will be able to observe the heart beats
use a colorimeterthank you man! :) rep for u
use a pipetter to measure a certain amount of water usually a 1 cm cube
mark the absorbance as 0 to the water
calculate the absorbance of the dye by the solution
thank you man! :) rep for u
i cant wait for tomorrow!! tomorrow is the unit 3 external lol
u cant wait???? dude im freaking out!!! :olol yeah i wanna do good!! ive been studying so hard and i feel like im ready to ace that exam :D besides 20 minutes left for it to be tomorrow :p
the higher the temp the more pigment comes out
except for zero, i dunno why tho
yep and at 70 degrees the pigment is destroyed or all the pigment has gone out aand not a lot left so a very small amount of pigment comes out
correct me if im wrong tho :/
and tell mee Psyclax
what did u study
like just the core practicals?
Yeah thanks.... I almost did that... and I just read through the information in unit 1 & 2....
Good Luck tomorrow everyone... Hope the second question is an easy one!!!!!!!!!! ;D
thanks :) i took the exam today, it was very easy :)
it was!! thank god...im nervous, chemistry is on thursdayyeah!! i know good luck! hopefully it would be as easy as today =)
yeah!! i know good luck! hopefully it would be as easy as today =)
So how was your chemistry exam?
what do we have 2 study for the unit 6 next tuesday ?!
hey cud some one help me
cud sum 1 tell me how do u do q2d of the sample paper w2 for biology??please i reallly need to know
draw a range bar
hey yeah i think its the same as an error barummm just one Question....i calculated the mean 1.80 and made a bar graph of the overall mean so the range bar wen drawn wont pass through the mean is that okay?
not sure tho
correct me if im wrong
and heyy nno problem :)
Explain why many animals have a heart and circulation??Dude ....
this is from the specification guide for biology Edexcel
well the problem is in the syllabus it says the strand used for mrna synthesis is the anti sense strand and my teacher told me it was the sense strand so i dunno which onei guess so lol but im not sure
but wat u r sayin is dat the anti sense strand has nucleotides complimentary to those in the sense strand?
i guess so lol but im not sure
Here's one question i got, it's a practical we need to know for unit 1
Describe how membrane structure can be investigated practically by the effect of alcohol concentration or temperature on membrane permeability.
Can someone plz help me on this one
thank you.
Do we have to memorize the Mendel's laws? cuz I'm confused.thanx in advance.
thanx kim.
but plz I need help in this question:
Descripe the principles of gene therapy and distinguish between somatic and germ line therapy.
sorry for the late reply but i suck at typin so i scanned the notes as usual
lol
hopefully this can help ya
nope i dont
Thanks a lot kim. it is really helpful but do u have the steps of gene therapy??. Anyway Thanks for ur great effort and Thanks in advance...
thats ok mate, im having alot of it + it wouldnt be nice from me if i dont wait, thanks alot, ill wait, but note that my paper is tomorow ;D
well, thats perfect !!!
thanks pal, to be honest with u, im solving the genetic questions from the examwizard files and i find it totally weird and diffferent from the new syllabus, so i find some difficulties,
thanks aloooot kim
im having some problem with Jan 2009 question 4) b) and c)
replies appreciated asap
thank you.
welllol i meant january 2009 unit 1 question paper lol
4b-glycogen is only made of 2 monomers of glucose so it cannot have any form because only wen these 2 combine will it give glucose
but protien on the other hand are made of amino acids
there are 20 amino acids in our body which can each combine wid each other to give a different form of protien
4c-rna van be trna or mrna .as mrna is used for protien synthesis so all the rna will differ from each other as each will specify for a particular protein
hope u understand if u dont tell me
ok here goesthank you very much =]
4bi-control the temperature
and volume of beetroots used should be same(to make sure they have same conc of pigment)
ii-there is a chance that wen u cut the cylinders of beetroot sum of the cells will get damaged causin the pgments to leak out
iii-the student should have washed the cylinders wid distill water to remove any damaged cell or extra pigment
ci-it increases
ii-well for this i am not sure but u cud say that ethanol causes the disruption of the cell wall so the pigments can leak out.also as it is for 2 marks u can say that ethanol is a polar solvent and usually polar solutes dissolve in polar solvents so lipids might have dissolved in ethanol
i just wanted to ask,
the notes on posts 62,67,72 are corresponding to which unit ?
then i no longer need them ;D
paper was great, i used my A2 knowledge in the last question and some questions was tricky, we'll reveal some answers in 24 hours ;D
i think i messed up on 1 as well, but nt really importnt, we can still score good grades i guessofcourse hope
yeah same here i felt good on this exam!! for all the questions i had confidence in my answers :D inshallah we all get good grades
i guess 24 hours is over!
Yes, you can now discuss.
ok here we go,
-why do we measure the initial rate of reaction?
-what was it for the mcq which was about the DNA, is it 2 pentose sugars joined together or 2 phosphates?
-what was the stagr of the cardiac cycle and the reason?
i wrote because at the begining, the reaction's rate is at its maxiumum as the conc. is at maximum too.
for the second one, i made it 2 pentoses joined together ;D dono wat made me do so,
and i wrote diastole too but i wrote a different reason which is related to valves ;D
number of people was 310 ;Dlol i wrote sum crap in that answer
the easiest question was the one about tumours, it was lovely ;D
and what did u write for the von bla bla factor question where they said use ur knowledge of the blood clotting process???
and the one abotu cystic fibrosis, there were 2 questions,
one said how a gene mutation results in ......
and the second was why ppeople infected with cystic fib. will be infected with this bacteria rather than people having no cysticc fib.
overall paper was good, wishing a similar unit 2 paper, im ready for surprises but still hope we get good grades isa
Hey nyc to hear every1 did well ........my one was good ;)lol dont worry u will get one 8)
hopefully unit 2 will be just as great
after M1 i badly needed a good morale booster :P
lol dont worry u will get one 8)
gee thanx ! best of luck 2 u ! ;D
ooooooook thanks for tryin
ill just write coding strand and not even mention sense or antisense lol
Do we have to memorize the Mendel's laws? cuz I'm confused.thanx in advance.
i read it in the book, its called the anti sense strand, which acts as a template for the coding of the mRNA. By the way,wats the enzyme called for DNA synthesis ? DNA Polymerase or DNA Ligase or DNA Helicase, cause i read about this some where which says that any of these three can b written :S ???
good to c its helpin u ppl!
i goy chem 2 today so please pray for me !
just the read the pages in the book
wat's important to remember about totipotency??
hey kim what are your expectations for bio tommorow
The amino acids are synthesized to proteins in ribosomes in RER by translation
Next the amino acids are bounded in vesicle that bud off frm cisternae of RER that transport the protein across the RER network and cytoplasm and fuse wid the golgi body-where the proteins are modified to glycoprotein/lipoprotein etc.Then secretory vesicles are again released by the Golgi body which fuses with the cell membrane and releases the protein outside cell by exocytosis
could someone give a quick review on the vaculor, symplast and apoplast pathways my teacher told me there is a possibility that they will come
hey kim do u have the organised papers that T.Q provided if so tell me cz i have a question in them
part b
i did the same thing but in the answers file they said its wrong u see this A diagram is difficuilt to figure out
answer is
BADCE
yeah thnxs i got it but still i have a small question if we have 5 diagrams and last diagram we said is E which is anaphase as the one before it metaphase
what could A, B, D stands for one should be for prophase and interphase what about the last one seems like this question kind of rubbish
k well i read somewhere tht u were predicting cancer stuff
what are those? can u plz explain. :)
can someone help me with january 2009 unit 2 question 1 b) i)
idk how the diagram should look like
well it is pretty simple
for eg lets take skin cancer
the colour of the skin is caused by melanin
melanin is produced by the tyrosinase enzyme
melanin is stored in specail cells called melanocytes in organelles called melanosomes
cancer is caused by genes and environment
cell divison is controlled by 2 types of genes
protoncogenes
and tumor supressor genes
UV radiations causes the conversion of protonco to onco genes and tumor supressor to tumor activator genes
which results in the uncontrolled division of cells and formation of tumor
also some general facts about cancer u shud know
cancer cells divide rapidly to form a mass of abnormally growing cells or a tumour which invades the surrounding tissues
the uncontrolled division is called metasis
a tumour that invades surrounding tissues is called malignant
cancer is when the rate of cell division is greater than the rate of cell death. Cancer could also form tumour which is abnormally living cells that invades other cells. Tumor could also break releasing small clumps of cells which we call it the metastasis method. The cancer cells are also able to live longer than normal healthy cells. Cancer could be formed by either a change in the enviroment or by mutation (gene changes). ok now for the 2 important parts about the gene mutation which causes cancer 1. supressor gene which removes the break on the cell cycle which increases the cell division. 2. protoncogenes which increase the amount of protein provided. The tar in the ciggeratte could cause this protoncongenes and the supressor thingiiis. As for the role of the enviroment u could talk about the uv light and how does it burn the skin and cause cancer + the melanin production where the uv causes the putitary gland to form MSH hormone, MSH could then join to receptor, move inside the cell and turn the gene that is responsible for the formation of tryosenase on. Tryosenase then converts the tryosin to melanin. Many melanin would join/get near to each other preventing the uv from reaching the cells which results in cancer and mutation
THANK YOUUU!!! :D
They might also bring u a normal graph and ask you to describe their values
that's everything
k can someone plz explain the maoa?
i need help with gene expression and differentiation :( n also, im confused in learning the mitosis stages, can anyone give me an easier method :| sovvy fer the botherrrr :3
THANKS :D
wat about me kimmy :( ?
n lol i was on the MAOA page but after ur summarised it, i don't need to read it n i got it better with ur explanation too :) Thanks :) JazakAllah
ok welll
MAOA is monoamine oxidase A
it break downs nuero transmitter such as serotonin and dopamine
if the level of MAOA is raised or decreased it causes mutations
low levels -nervous disorder
dependance on alcohol
parkinsons disease
high levels-risk takin and aggressive behavior
tension favors high release of MAOA
and maltreatment causes low release
this enzyme is produced with the help of a dominate gene located on the X chromosome
if there is to much of this enzyme it breaks down too many of the nuerotransmitters which can affect ur mood
hence it is linked with depression
but i remember MAOA being majorly in males so shouldnt it b on the Y chromosome ? :o i could b wrong
hahaha dont worry
i havent forgotten ya
thank you
well for mitosis i am afraid there is no easy u will have to learn it
but i will type my notes out for ya maybe they will help
for the gene expression cud u be a little more specific??
haha i just checked it is on the X chromosome
so girls have double the chance of getting it
well i did one of the papers and there was a question regarding gene differentiation. when i checked the mark scheme, they gave the points as for example, a stem cell in a particular part of the body requires production of ATP for instance. so a few of the genes which aid in ATP synthesis are EnViRnoMeNtAlLy activated. these cause the specific protein to b synthesized and so it changes it state of pluripotency and forms a speciallised cell. i read this a long time ago so my explanation is abit vague,
as fer the others, don't actually read my explanation unless u can explain it to me :P cause it mite give the wrong idea so plz, i don't wanna b the reason if such a question comes up n my explanation which U hav memorized, goes wrong :(
nice handwriting ;D
wooowwwww, neat handwritting MashAllah, mines all huge and joined up and dirty and unordered and unorganised n u name it :3
n Thanks :) !
welll all i know about gene expression is that they will turn on into what it is specialised
it first is totipotent then it turns to be pluripotent
so it is turned into an organ like the heart
but we dont know when thy turn on or off
but i dont get ur ques either.. sorry
im searching an explanation for my answer on google and the first link i get is : Is there a pattern of gene differentiation in the Indian populations ? -_- . . . lol and no im not an indian, its jus abit ironic for me :P
haha that is hilarious
which nationality r ya?
haha that is hilarious
which nationality r ya?
im Paki, n u ? :)
awesome so m i
hi5
u shud join us at the pakistani hea thread
sure ( hi5, Tish ! (the sound :P ) ) n yh sure, after the exams inshAllah :)
haha nice sound effectsyh sure :), as i read in some of the early posts on other topics, u in Dubai ? :)
ok iA lukin forward to seein ya there
yh sure :), as i read in some of the early posts on other topics, u in Dubai ? :)haha behind the scener ehh??
i havta go sleep ppl
pray for me! :)
salam
good nite sweet drms all the best, inshAllah the paper will b great fer ya ! :)
well its not like behind the scenes lol i was checking fer some important points n ur post comes up so cant jus jump my view, rite :P
well im ur neighboor, here in Riyadh, Saudi arabia, in the middle of the dessert :<
haha lol
nice
okay now me going to sleep have to wake up in about 7 hours lol
ok good night and Allah Hafiz
hey guyz...i hav a qn in Bio A2 unit 6b:
what is meant by a null hypothesis?? ???
hey Thanks buddy!!...JAZAK ALLAH :)
could any person explain to me the DNA profiling/finger print method
Hey.. Could anyone help me please with the condensation reaction between 2 fructose molecules? i mean how the end product will look like :S and how could i draw an unsaturated lipids :D
Two fructose molecules will undergo condensation reaction to form a disaccharide. You just need to draw the two fructose molecules side by side. Then the H from one molecule will combine with the OH of the other molecule to form the sugar along with the release of water. A 1,4 glycosidic bond is formed.
Watch this (http://nutrition.jbpub.com/resources/animations.cfm?id=6&debug=0). It's the formation of sucrose from glucose and fructose. The same principle will be applied for your question. ;)
Unsaturated lipid are those which carbon-carbon double bonds in their hydrocarbon tails. So you just draw a normal lipid and add a C=C in its tail. ;)
The picture attached represents an unsaturated fatty acid. So you just have to include it in your lipid. :D
Saturated lipids are mainly fats and are solids. Unsaturated lipids are mainly found as oils.
Thanks for the precision dude. :)
But I think she only wanted to know how to draw the structure of unsaturated lipids ;)
Then I am sorry.
and i got another question the bond in fat-->esterIt's not always this, it can be 1,6 glycosidic bond as in amylopectin. So just write Glycosidic Bonds.
Carbohydrates-->eg 1,4 glycosidic Bond and in Protein ----> wht's the name of this bond if there is ? I know My Questions Are kind of stupid but iam really freaked out from My.AS as it my first tym :S and iam doing two math units:(
Hey..That's my Biology A.S and i was studying Carbohydrates "Condensation between 2 glucose" so i thought of joining the glucose and fructose i got a stupid shape:D anyway thanks for ur help guys i really appreciate it :$ and tht diagram was really helpful I mean i need a diagram when a glucose is joined with a fructose molecuole :D
and about the unsaturated lipid i know there will be a double bond or a couple of them but how will this differ if we join it to form a triglyceride and if we join a saturated lipid :D
Deadly_king --->thanks iam really grateful:) i hope ur always here to help me out :D :$
Master Key-->thank you :D
and i got another question the bond in fat-->ester
Carbohydrates-->eg 1,4 glycosidic Bond and in Protein ----> wht's the name of this bond if there is ? I know My Questions Are kind of stupid but iam really freaked out from My.AS as it my first tym :S and iam doing two math units:(
Why it is important to have calcum ions during the process of blood clotting :D? My teacher said i don't really have to know this but iam really curiuos=p
A triglyceride will consist of 3 fatty acids joined b y ester bonds with a glycerol. Any of the three fatty acids, if it contains a double bond will cause the triglyceride to be saturated. ;)
I'll try to help you as much as I can. :D
In protein the main type of bond i peptide or amide bond. But later you'll do the different structures of proteins and the oether bonds which define each one of them. ;)
No worries.......your questions are not stupid. :)
There are 4 bonds:-
COVALENT BONDS
HYDROGEN BONDS
DISULPHIDE BONDS
HYDROPHOBIC INTERACTIONS
There is also ionic bonds dude :D
So in all that makes 5 bonds. I did not mention it because I wanted her to do it in class first. ;)
covalent bonds ----> peptide or amide
check above, i thought that that much would be enough for her.
It should be enough now :D
Nevertheless she should get acquainted to it first in class. ;)
Only if she has doubts or is not understanding something should she consult us. :)
Else she just might turn lazy. :P
Guys I srsly need ur help in this ECG it's killing me =(
It's like so confusing could u plz summarize it using any diagrams:s plzz
okii can anyone please let me know frm where i can get the biology a.s syllabus :D i actually don't know wht i should have to know in ecg iam just studying from the book =(I tried attaching but it's taking ages >:(
Hey guys, if anyone has the May/June 2010 paper of biology, i need help on Q2b and 3a(ii)
I couldnt find it on the site but i have it as homework
What is the question? I dont have edexcel papers so tell me the question.Well, the first is about a diagram so u cant answer it.
Well, the first is about a diagram so u cant answer it.
But the second says, Explain how the properties of a phospholipid contribute to the structure of the cell membrane.
my scanner doesnt work :P
Well, the first is about a diagram so u cant answer it.
But the second says, Explain how the properties of a phospholipid contribute to the structure of the cell membrane.
Guys I srsly need ur help in this ECG it's killing me =(I'll give a simple explanation. Simple according to me :P I hope it helps.
The graph below shows changes in the blood pressure in the aorta and the left ventricle during two complete cardiac cycles.I had this question in an exam xDD
(a) On the graph, draw an arrow to show when the left atrioventricular (mitral) valve closes.
(b) Use the information in the graph to calculate the heart rate. Show your working.
Don't know how to calculate the heart rate (b) , anyone explain
Markscheme says: (b) 60 ÷ 1.0 ; [accept equivalent calculations] = 60 beats per minute ; [accept range 60 to 64], but how does 60 beats come only pressure and time in seconds is given? Thanx in advance :)
I had this question in an exam xDD
anyways to calculate the heart rate:
1 beat -----> 0.96sec (from graph, since a full beat finishes then)
X beats ----> 60 seconds
Then cross multiply it to get the answer
X = 60/0.96 = 62.5
See the picture if u still dont get it.
+rep ;)Thank you ;D
how can i explain ionization:D i know stupid question though=pIonization is chemistry ?
how can i explain ionization:D i know stupid question though=p
June 2010 Unit 1 Question 3 a ii)Molecule A --->Phospolipid
hey guyz...i hav a doubt in edexcel biology unit 6B...cud any1 help me wid d statistical tests part?
i know dat v r not expected 2 know d formulae or fine details of each test n i even know dat v must only concentrate on selecting d correct type of test and demonstrate our understanding on how 2 interpret d results-this has been stated in the revison guide.
cud any1 plz temme how 2 select d correct type of test and demonstrate our understanding on how 2 interpret d results???
Is the chi-squared test in the syllabus???
guys i cn't find the a.s pprs:sYou can get them of FEP.
please help me to find them :s
Thanks weaam<3 I appreciate it :)ur welcomee ;D
Guys from where do i get the examiners report if anyone can email me it :s
How to justify validity +reliability of results?
This might sound like a stupid question,but I m not sure how to tackle this for a lab report.I did a searh on google+TSR+SF & found nothing.
For the reliability I have come up with this : The experiment was repeated twice making the results more reliable.
To justify the validity,I ve no clue how to word it.
This is for the effect of heat on membranes.
Rep for your help.
Thanks
How to justify validity +reliability of results?
This might sound like a stupid question,but I m not sure how to tackle this for a lab report.I did a searh on google+TSR+SF & found nothing.
For the reliability I have come up with this : The experiment was repeated twice making the results more reliable.
To justify the validity,I ve no clue how to word it.
This is for the effect of heat on membranes.
Rep for your help.
Thanks
Do any of you have any tips for analysing graphs,some tips can I got from here: http://www.thestudentroom.co.uk/showthread.php?p=26347179&highlight=graph
,but if you have anything to add,that would be great.
+rep :)
anyone knows how to calculate the standard deviation using the calculator
In the edexcel revision guide, it says they mark accourding to CORMS:Insert Quote
C- Control
O- Organism
R- Repeat
M- Measure
S- Same (variables)
Hopw that helps ;D
I just saw it ,I have a copy of it. ::)Hahaha ur welcomee ;D
I had forgotten to read through that part.
Thanks :D
How can a mutation in a gene switch cause anatomy to evolve,without the gene changing?
I don t get this, if there is a change in the gene switch the gene won t be transcribed normally,so the gene will change,no?
thanks,it s a bit late as I already sent the homework for the question.It s not on the curriculum(too much detail) anyway.I wrote what I could from my textbook.Sorry,funny about the fruit fly though
sorry about that I should have edited my post/removed it. Hopefully you got something out of this.Sorry :-[
I have some few questions from unit 4 (A-level):
- Suggest two enviromental conditions that could increase the rate of oxygen production in plants
- Describe how a forest could be managed sustainably in order to ensure a continual supply of timber for the future
-Name a method by which global sea temperatures can be monitored
-Some recovery in the great barrier reef may be taking place at present. Suggest a possible explanation for this, other than change in sea temperature
-HIV positive people were excluded from the data (ie data about number of new TB cases). If they have been included suggest how the data would differ. Give an explanation to your answer.
-Give one example of physical evidence that could be retained from the original investigation of a crime scene and explain why the sample is suitable for a DNA test to be carried out.
SOrry for being thick, answer what u can if u please :) thanks alot ;D
-Maybe reducing CO2 emissions? Hmm it's unlikely.. I'm not sure to be honest.
-Give one example of physical evidence that could be retained from the original investigation of a crime scene and explain why the sample is suitable for a DNA test to be carried out.
hey wt about the quadrat/transect experiment? i knw nothin how 2 do it!
Something like this, you mean?
How about sencors?
check these - http://en.wikipedia.org/wiki/DNA_profiling
http://www.answers.com/topic/genetic-fingerprinting
Here's what I think are some correct answers;
-Any condition which will increase the rate of photosynthesis over respiration so the plant produces more oxygen (e.g. 1.higher temperature 2.brighter sunlight/light... etc.)
-By planting seeds after cutting trees.
-Maybe reducing CO2 emissions? Hmm it's unlikely.. I'm not sure to be honest.
-The increasing acidity of the sea (lower pH because of more CO2 absorption by the sea).
-The number of people affected with TB would have been higher. Explanation: TB is an opportunistic disease which only attacks when your immunity is at its weakest. HIV kills the T-helper cells in your immune system which makes it very weak, and so TB finds the perfect time to attack.
-Blood/Falling hair... etc.
Refer to DNA profiling. I'm sorry but I'm a bit short on time right now.
I hope it helps :D
Good luck mate!
The links have too much general not required information.. They won't help.
Perhaps reading what you post before you post it is a good idea ;D
Plant Fibres-why do some stretch more than others?
Any ideas,googling didn t help
Has it got to do with their structure or their composition( materials they are made up of)?
Thanks
+rep
I was given these hints: Think about the molecular structures involved. Proteins and polysaccharides form secondary structures - what are they? What types of forces are involved in them? What about tertiary structures?
My attempts - I have no idea other than the glycosidic bonds in cellulose.I don t know what secondary structures polysaccharides form other than long chains.
I know there are hydrogen bonds in secondary strucure in proteins+varipous bonds in tertiary structure .
I m really stuck plz help!
Fibers are elongate cells with tapering ends and very thick, heavily lignified cell walls. Fiber cells are dead at maturity and function as support tissue in plant stems and roots. The lumen or cavity inside mature, dead fiber cells is very small when viewed in cross section.
thanks + rep,to my own surprise I was thinking the same as you (I m not the best bio student there is)
how would you keep pH constant?
hi
I made different concentrations of catalase (from potato) and was wondering how I could accurately say that the enzyme concentrations will be different in different areas of the test tubes as some particles will sink to the bottom.I m not sure if its the heavy particles ...
thanks
+ rep
Can somebody let me know what we need to know about the structures of proteins;
Primary Proteins, Secondary Proteins, Tertiary Proteins & Quaternary proteins
Do they have functions that we need to know?
& Can someone let me know what are the shapes of each required to know?
Thank you.
Thank you! :)
hey can someone please help me out with the fluid mosaic membrance structure .. what do i need to know??
thanks in advance
hey can someone please help me out with the fluid mosaic membrance structure .. what do i need to know??amelia's given a good descriptn....and il add:
thanks in advance
In june 2004 module 1:plz can any one help withthat
Q 6 (c) answer said post transitional modification ??? what is it exactly ? how it affects the no. of amino acids to be less than the no. of codons ?
Q 6 (d) why in mark scheme the word Two underlined ??? is it a must to be included in my answer if yes then why exactly two :(
plz reply as soon as possible
Thanks in advance
plz can any one help withthat
Can you post the questions, please? Everyone here doesnt take Edexcel Biology.ok here is the link http://www.xtremepapers.net/Edexcel/Advanced%20Level/Biology/2004%20June/Unit%201%20June%2004.pdf
Is post translational modification even there in your syllabus?
Anyways, This video might help - http://www.youtube.com/watch?v=OtyhPEyLhvA&feature=related
In june 2004 module 1:
Q 6 (c) answer said post transitional modification ??? what is it exactly ? how it affects the no. of amino acids to be less than the no. of codons ?
Q 6 (d) why in mark scheme the word Two underlined ??? is it a must to be included in my answer if yes then why exactly two :(
plz reply as soon as possible
Thanks in advance
Posttranslational modification (PTM) is the chemical modification of a protein after its translation. The modification of a newly formed protein; may involve the deletion of amino acids, chemical modification of certain amino acids, or addition of small molecules (eg, phosphate groups or sugars) to certain amino acids.Thanks for answering the previous question
d -I dont know what 'two' you are talking about but here is the whole answer.
(http://3.bp.blogspot.com/_KQ8_woKrwiE/SoMNQSl0JhI/AAAAAAAAADE/o0paPK0__YQ/s1600-h/2207.jpg)
http://3.bp.blogspot.com/_KQ8_woKrwiE/SoMNQSl0JhI/AAAAAAAAADE/o0paPK0__YQ/s1600-h/2207.jpg
Thanks for answering the previous question
here is the mark scheme Q6(d) answer plz
Thanks in advance Jazak Allah Kairan
Where's is it, hon?oopps :-[ sorry formy careless
oopps :-[ sorry formy careless
here its my dear :)
http://www.xtremepapers.net/Edexcel/Advanced%20Level/Biology/2004%20June/Unit%201%20June%2004%20MS.pdf
Q 6 (b) in this exam do it tell me http://www.xtremepapers.net/Edexcel/Advanced%20Level/Biology/2005%20June/Unit%201%20June%2005.pdf
other question in this photo the darker part the cristea right ?
The infoldings of the mitochondria are the cristae. The 'dark' fluid like material is the matrix.Thanks my dear :D
----------------------------------------------------
For question 6, I'm not at all sure. But anyways,
Take the two points of coincidents. (Start line of each scale and another point of coindents along the scales.)
Calculate the relationships between them.. On the scale shown there are four divisions on the stage micrometer and 10 divisions on the eyepiece graticule. Thus, 4/10 = 0.4 units. Each unit on the stage micrometer scale is 100 micrometers. Therefore, each division on the graticule scale will be 100 x 0.4 = 40 micrometers. The method is clearly shown here - http://www.xtremepapers.net/CIE/International%20A%20And%20AS%20Level/9700%20-%20Biology/9700_nos_ps_2.pdf
Thanks my dear :D
why daphnia needs aheart and circulATory system ???
answer all questions in figure provided plz ???
decreases[/i].
excuse me can u say to me what does he means to complete the table is there anything missing
c) You have to write the safety precautions needed to take before you do titration. Gloves, goggles etc...
he means safety precautions or any variables to be controls
D)i) Canned vegetables - lose vitamin C during processing. If the canning water is thrown out, even more is lost.
ii) Cutting the fruits and vegetables - Once the protective peels or coverings of fruits and vegetables are cut, the fruits and vegetables begin to degrade and lose vitamin C.
he said fresh friut can u say another thing about the first idea u said
I'll let you do the SAQ6 yourself. ;)
hahahah.....
well anyway thanks i'll tryand post it here
soorry i wrote in bold as i didnot know how to quote each part separately :-[
excuse me can u say to me what does he means to complete the table is there anything missing
he means safety precautions or any variables to be controls
he said fresh friut can u say another thing about the first idea u said
Actually, I didn't find any table myself. So, I just compared the results in the above table.
The question just said precautions. Why dont you write about both? First, the control of variables and then the safety.
As in? Both fruits and vegetables loose about 10 to 90 percent of vitamin C when they are canned. You can google to find more.
I hope it's clearer.
here I am really surprised ::) with the answer if anone of u guys know any idea abt it clear that doubt for me plz
Q5(b)
http://www.xtremepapers.net/Edexcel/Advanced%20Level/Biology/2007%20June/Unit%201%20June%202007.pdf
as in the mark scheme the answer is this(b) prophase, telophase, metaphase and anaphase;
while what i thought that it would be metaphase,telophase,anaphase, prophase ??? ???
second question Q 8 (b)(i)
plz answer & show ur steps {what i dont know is what is the max. rate as if u looked at the mark scheme u may find max.rate is 0.0069 and i donot know how to get that ???
http://www.xtremepapers.net/Edexcel/Advanced%20Level/Biology/2008%20June/6101-01%20Biolgy%20%28Human%29.pdf
and mark sheme :http://www.xtremepapers.net/Edexcel/Advanced%20Level/Biology/2008%20June/9042_GCE_Biology_msc_20080807_UA020010_doc.pdf
Thanks in advance sorry for disturbing
QuoteAnd, For some reason I'm not able to reply to your pm. I get an error message saying that you have blockedu can now i solved the probs and abt the max rate from where did u get 47 :-\
u can now i solved the probs and abt the max rate from where did u get 47 :-\
ahaaa Thanks ;D u took this value as in this range the rate is decreasing
I took a value some where b/w 40 and 68. :D
ahaaa Thanks ;D u took this value as in this range the rate is decreasing
Suggest an explanation for why a whole muscle might respond differently to a stimulus than a single fibre ... its from the edexcel bio a2 book
Salaam all, I have a few qns....I hope u guys will be able to help to your best.
1) what is the difference between random error and systematic error?
2) what is the difference between a belt transect and a line transect?
Have you guys got any pics of belt transect and line transect in your books, guides, notes etc. I want to know how each one looks to make their difference clearer.
Tried googling this and got answers but they were not very clear and people over here have better info than google :) so please share your info. thanxx...:)
1) The main Diff. is one can be corrected by repeating experiment but other cannot.and that one which can be corrected by repetition is the random ;D
1. Explain why base pairs are a suitable way of measuring length of a piece of a DNA?
2. Explain why (1) Penicillin, (2) Tetracyclin and (3) Quinolones are not effective against viruses?
Can u please help me in these questions
1) Explain what is meant by the term genetic carrier?
2) One of the polypeptide chains in the haemoglobin of a person with sickle cell anaemia has a change in one of its amino acids.Explain how change in
DNA can lead to a change in a single amino acid in polypeptide chain.
I appreciate ur help!!
what is the role of elastic recoil in the arteries ??
Can sum1 plz explain the t-tests and confidence levels ? or suggest a book where its explained wel but not 2 detailed ... just wats needed for unit 6 bio ...t-tests are usually sum statistical tests carried out to check the relationship between variables and the validity of an experiment...now in u6 xmz...usually, theyl giv u the value of the experimental t-value, and a table comprsing of t-values for the experiment. all u hav 2 do is check d value of t correspondin to 0.05 value. if ur t-valu z greater or equal to this value...dat means dat u hav a 95% confidence that the experimental t-value is significant. and the null hypothesis is rejected! so then u can accept da relationship shwn by the experimnt.
research type q ?? :Sno paper 3 the second question in each recent past paper
didnt understand.. are u talking abt the paper 5 scientific article thing ??
Salams :)
I also have a small confusion with da following: Please mention where they are found n their definitions:
a. Baroreceptors
b. Stretch receptors
c.Chemoreceptors
is a and b the sam thing?? ???
dont u guys read the text book ?? ^this thing is fully explained in the edexcel a2 biology book...i dont have the A2 edexcel book and i dont take A2, im taking the AS edexcel biology
if u want ill explain the whole thing here in short but its beter if u have a look at it urself beter understandig :)
During an investigation or experiment, the independent variable is controlled by the experimenter.The dependent variable is measured to give the results. For example, in the Daphnia experiment in AS, the independent variable is caffeine concentration because it is controlled by the experimenter and the dependent variable is the intensity of red colouration (absorbance) because it is the one that is measured to give the results. The dependent factor depends on the independent variable....hope it helps....Thanks
this is all u need to noe for the AS i think.... if u have seen any q like this in any pastpaper then do let me noe caz the controling of the heart beat by nervous system is in A2
january 2011 unit 1 question 1 b) where they give us this graph , how do we describe the results, ok i see the graphing for the control group and the treatment group but then theres that line in the middle of each bar i really dont get it :Sthe line u r talking about is the error bar... it is a range in which the results cud have been... wat u can write abt it in the ans is tht.. the range was larger for the treatment group compared to the control group
please help asap
thank you <3
the line u r talking about is the error bar... it is a range in which the results cud have been... wat u can write abt it in the ans is tht.. the range was larger for the treatment group compared to the control group
mention tht the control group has shown an mean increase and treatment group has shown a decrease.. the diference is means is 70mm3 ull get full marks :)
here are some unit 1 revision notes... good to go thru themto which book are the related to as they say see book page etc.
Vincristine is a drug used in the treatment of cancer. It prevents spindle formation during mitosis. The result of a root tip squash on the roots grown in a solution of vincristine showed an increase in the percentage of cells found in one of the phases compared with roots grown in water. State the precautions that must be taken for the results of the comparison to be reliablehow many marks is the q for ??
hey could someone plz tell me the procedure of this core practical --- how to investigate the effect of temperature on seedling growth rate? thnxx..
umm y dont i remember any such practical :Scheck out the file I uploaded, it has that practical no the structure of the membrane and the effect of temperature on it etc.
seen in any past paper ??
how many marks is the q for ??4
the concentration of the solution shud be known and controlled..
the roots shud be of the same variety of plant..
the mass of root taken shud be same..
3 points for 3 marks
can someone complete the remaining blanks for me pleasethis is A2 stuff .. didnt study tht yet =\
Heart wall muscle is a special type of muscle called Cardiac muscle. This muscle can contract or relax without nervous stimulation and is thus described as _____________. To ensure that the cardiac cycle stays in sequence there is an in-built control mechanism. The wall of the right atrium contains a special region of muscle called the ______________ which sets up a wave of electrical activity causing the atrial walls to contract almost simultaneously. There is a band of fibres between the atria and ventricles which _______________ the wave of activity passing to the ventricle walls. The wave of activity is picked up by the ____________ situated in the septum at the junction of the atria and ventricles. The wave of activity then passes down the septum in the _________________ causing the ventricles to contract.
Thank you
this is A2 stuff .. didnt study tht yet =\are u sure? :s i mean i got this from some worksheets i have from school so maybe it would help with anything relating to the AS material
Heyyy actually the core prac i waz talking about is --describe how to investigate the effect of temperature on seedling growth rates. It is from the Edexcel A2 Biology specification so u might not have studied it "gumnam" because i assume u r doing AS ryt?...anywayz Thanks for helping...lets wait for someone else to reply...anyone else doing A2 Biology??.....i need to know the procedure for this core prac as it is from the specification.....i have all the Edexcel A2 biology core prac procedures but not this one ??? actually it is a 'part' of a specification point....the spec point of which it is a part of is --- Describe how to investigate the effects of temperature on the development of organisms (eg seedling growth rate, brine shrimp hatch rates). i know how to investigate the effect of temp. on brine shrimp hatch rates but not the seedling growth rates....these both appear to have a similar procedure but not exactly the same....if anyone of u studies in a school and ur teachers have provided u with the procedure of this part of the core prac plz do tell me....many Thanks to all....and good luck with ur exams...actually i m doing AS and A2.. i just havnt studied A2 well yet.. and yea.. i didnt go thru the specification so i think thts y never saw this practical caz i dont have it any notes either but ill let u noe as soon as possible :)
ohh yes ofcourse we measure the initial rate of a particular reaction a short time after mixing the reactants together.Thanks alot mate ;)
These are the details that i have collected from the AS Core Practical notes. They will help u understand all this very well
Measuring the rate of enzyme reactions:
1. Firstly you need a signal to measure that shows the progress of the reaction. The signal should change with either substrate (S) or product (P) concentration, and it should preferably be something that can be measured continuously. Typical signals include colour changes, pH changes, mass changes, gas production, volume changes or turbidity changes. If the reaction has none of these properties, it can sometimes be linked to a second reaction, which does generate one of these changes.
2. If you mix your substrate with enzyme and measure your signal, you will obtain a time-course. If the signal is proportional to substrate concentration it will start high and decrease, while if the signal is proportional to product it will start low and increase. In both cases the time-course will be curved (actually an exponential curve).
3. How do you obtain a rate from this time-course? One thing that is not a good idea is to measure the time taken for the reaction, for as the time-course shows it is very difficult to say when the reaction ends: it just gradually approaches the end-point. A better method is to measure the initial rate - that is the initial slope of the time-course. This also means you don't need to record the whole time-course, but simply take one measurement a short time after mixing.
4. Repeat this initial rate measurement under different conditions (such as different substrate concentrations) and then plot a graph of rate vs. the factor. Each point on this second graph is taken from a separate initial rate measurement (or better still is an average of several initial rate measurements under the same conditions). Draw a smooth curve through the points.
Be careful not to confuse the two kinds of graph (the time-course and rate graphs) when interpreting your data.
I think we do not measure the rate throughut the whole reaction because it is better to simply measure the initial rate of a reaction than to monitor the whole reaction because the initial rate measurement gives just as accurate a result and saves time ofcourse....this is all i know..hope i helped...
can someone complete the remaining blanks for me please
Heart wall muscle is a special type of muscle called Cardiac muscle. This muscle can contract or relax without nervous stimulation and is thus described as _____________. To ensure that the cardiac cycle stays in sequence there is an in-built control mechanism. The wall of the right atrium contains a special region of muscle called the ______________ which sets up a wave of electrical activity causing the atrial walls to contract almost simultaneously. There is a band of fibres between the atria and ventricles which _______________ the wave of activity passing to the ventricle walls. The wave of activity is picked up by the ____________ situated in the septum at the junction of the atria and ventricles. The wave of activity then passes down the septum in the _________________ causing the ventricles to contract.
Thank you
How do we calculate the standard error and draw the error bar?
Could someone please help?
Thank you :D
can some one tell me wats the diff between c & d .. i mean are they in the same stage of mitosis ??
For standard error, read this link (http://www.wikihow.com/Calculate-Mean,-Standard-Deviation,-and-Standard-Error) carefully. If you dont get it, I'll explain later. :PThank you :D but I can google too :P
Error bar with example - http://www.ncsu.edu/labwrite/res/gt/gt-stat-home.html
Thank you :D but I can google too :PBy the way we dont need to noe all this stuff for unit 3 exam do we ?? :S i thought all tht part was in unit 6 =\
Standard deviation = ? = sqrt [(?((X-?)^2))/(N-1)]. What?? :-X ::)
Anyway I will get it from my friend now - she finally woke up :D
+rep for taking the pain .Thank you :)
Not a huge difference. The first picture is early Anaphase - chromosomes starting to pull apart & the the second one is just Anaphase (the stage which occurs before telophase).and Thanks amelia.. so we say tht both of them are from anaphase yea ?? or one is early anaphase and 2nd is late anaphase?? (i guess both ans wud be correct )
By the way we dont need to noe all this stuff for unit 3 exam do we ?? :S i thought all tht part was in unit 6 =\Did you check the sample paper for Unit 3?The graph has 1 mark for drawing the error bar. :)
what do you guys recommend doing in prep for the exam? do all the practicals or do the past papers?id say revise the practicals then solve pastpapers and time yourself for good time management thats all thats left to do, exam is tomorrow
no i didnt can u give me a link to it ??It's there in the edexcel site but something seems to be wrong with that site.Anyway -attached :D
Salams :)
I have a few questions regarding the Practical about the effect of temperature on the hatching success of brine shrimps:
1.What are the health and safety precautions to be taken?
2.Ethical issues arising 4m da use of living organisms such as brine shrimps?
Thank you soo much in advance!! :D
For people interested in a list of all the practicals, here I attached a file that has all the practicals needed for you to know + questions related to that practical.@blizz mayn do u have a similar thing for a2 ??
Enjoy :)
Heart wall muscle is a special type of muscle called Cardiac muscle. This muscle can contract or relax without nervous stimulation and is thus described as _____________. To ensure that the cardiac cycle stays in sequence there is an in-built control mechanism. The wall of the right atrium contains a special region of muscle called the ______________ which sets up a wave of electrical activity causing the atrial walls to contract almost simultaneously. There is a band of fibres between the atria and ventricles which _______________ the wave of activity passing to the ventricle walls. The wave of activity is picked up by the ____________ situated in the septum at the junction of the atria and ventricles. The wave of activity then passes down the septum in the _________________ causing the ventricles to contract.
http://www.mediafire.com/?k362jo55hwseq3hthns alot :)
This posted by some other user, i find it great help to keep me in track on what im to do for practicle, i finish each experiment from there and read the same experiment from my guides. i think for practicles thats more than enough ..
here are some other notes i dono if you have them or no
Gumnam, Vicoden, Raaga and Booklover, I think u guyz r doing A2 written Alternative to practical on the 25th ryt? I am doing this paper also, so y don't v come online tonight and discuss this paper? It would be gud....v can share ideas and whatever few notes v have and any other resources so that v can ask each other questions v hav a doubt about....what do u guyz think and where do u live?umm.. yea i m giving tht paper but i have chem exam tmrw so ill see if i get time and then we can discuss :)
if not today tomorrow?okay:)
Hi
I have the Biology unit 6B in 3 days, and i have absolutely no clue on what to do ???
Urgent help needed
I have a problem in one of the questions from measuring rate of oxygen uptake..
It would have been better to set up a second, control tube that did not contain living
organisms but had everything else the same.
a. What could cause a movement of the liquid in the control tube towards the respirometer?
b. What could cause a movement of the liquid in the control tube away from the
respirometer?
c. What could you do to correct your estimate of oxygen uptake if the liquid in the
control had moved too?
What is the answer for part c?
I have a problem in one of the questions from measuring rate of oxygen uptake..where is the q frm ??
It would have been better to set up a second, control tube that did not contain living
organisms but had everything else the same.
a. What could cause a movement of the liquid in the control tube towards the respirometer?
b. What could cause a movement of the liquid in the control tube away from the
respirometer?
c. What could you do to correct your estimate of oxygen uptake if the liquid in the
control had moved too?
What is the answer for part c?
@Assi1993: Thanks alot for your help:D
@guMnam: I got the notes from this site..I attached the file :)
hey man..
its easy.. bar chart.. 2 seperate bars representing means (NOT HISTOGRAM)
the range bars.. u take the 1st bar.. highest reading (draw a mark) then the smallest reading (draw another mark) then draw a line between them..
do this for the other bar.. u shld get some overlapping .. u compare man!
the median is in the middle therefore 174 cm:( i stii donot get the Q 3 a iii as in mark scemem said the far right hand box
its either the 2nd or 3rd boxes as eukaryotes share the same ancestral form with another domain
because the crossing over happens above the B parts so they stay where they are only the As change :)
:( i stii donot get the Q 3 a iii as in mark scemem said the far right hand boxpllllllllllllllllzzzzzzzz any one answer me :-[ :(
Guys does any one have january 2011 marking scheme for unit 2 biologyhttps://studentforums.biz/pastpapers/edexcel-january-2011-examiners-reports-(physics-chemistry-biology-maths)/
for tests..
u need 2 knw only 2... t-test nd correlation test (i dnt knw its others name)
t-test u use when u compare 2 things.. like u divide land 2 2 areas nd u compare between them
correlation is when there r dependend nd independent variables.. when something increases, other decreases (for example)..
got it?
no one is doing A2 Bio itseems =\
lol.. tmrw is the exam and no one has a doubt.. lol strange
i was in a mood of solving some
any ways.. best of luck every one =)
i hope u all did well
http://www.facebook.com/pages/Protest-against-Edexcel-Biology-Unit-4-Exam-130611/130890383657523woow O_O
^Do you have the answers for them ?No :-\
No :-\Where did you get it from ? :-\
Where did you get it from ? :-\I think its from the A2 SNAB biology book.
Try asking MKh. She might be able to help.
Answer 2: DNA profiling can be done by Electropherosis.
in biology for all units,
the first spec . point, it says---
Demonstrate knowledge and understanding of the practical and investigate skills in numbers 4 and 5 in the table of how Science Works on page 13 of this specification..
wat does that mean and wat does it want to know from us??? pls tel me about this???
Can anyone list down the main points for the practical: Measuring the effectiveness of an antibioticThis core practical is in the A2 context? It is in the A2 Biology Revision Guide.
Thanks
Biology,
Why does heart rate increase while individual anticipates exercise?
GCE edexcel student.
Thx in advance!
The anticipatory response is mediated through the releases of a neurotransmitters called epinephrine and norepinephrine also known as adrenaline and noradrenaline.
The sympathetic channel of the CNS increases heart rate by releasing the neural hormones - epinephrine and norepinephrine. These hormones are cardio accelerators. Before an event begins, if the individual anticipates with excitement and enthusiasm the event, heart rate increases dramatically without any muscular involvement. This provides the rapid mobilization of it's bodily reserves by revving the body's engine
How about the purpose of anticipatory response? is it provide the rapid mobilization of its bodily reserves by reciving the body's engine?
Edexcel unit 5
What is the difference between adaptation and habituation?
Thx in advance
Edexcel unit 5haven't done unit 5 yet so I am not sure if the answer will make sense to you.
What is the difference between adaptation and habituation?
Thx in advance
What's the purpose of increasing heart rate after the stretch receptor send impulses to cardiovascular centre in respond to the increase volume of blood that enter the heart during exercise?
Under the specification point, it says-
Analyse and interpret data on the possible significance for health of blood cholesterol levels of high-density lipoprotein (HDLs) and low-density lipoprotein (LDLs). Describe the evidence for a causal relationship between blood cholesterol levels ( total cholesterol and LDL cholesterol ) and CVD.
I dont understand what does it wants us to know about??? Can any one of u tel me wat does it wants and explain me in details. I didnt get wat does it mean by?? Please help me.
I can't find Unit 3 january 2oo9 Anywhere ! can anyone please link it :sI think it started from June 2009.
I wanted to know what is a null hypothesis and what is hypothesis actually i need these kind of terms which might show up in my unit 3 ;D any help please :)
I am confused with monohybrid cross.
Can anyone explain, how do we do it. :S
in the Daphina experiment in the book it's mentioned don't use a cover slip to provide sufficient oxygen for the Daphina while my teacher we should use it to prevent evaporation of the liquid should we or shouldn't we ?
Assalamu alaikum sister Romeesa,
Do you understand the concept as under the syllabus has asked us to-
EXPLAIN THE NATURE OF THE GENETIC CODE (TRIPLET CODE ONLY, NON-OVERLAPPING AND DEGENERATE)
DESCRIBE THE PRINCIPLES OF GENE THERAPY AND DISTINGUISH BETWEEN SOMATIC AND GERM LINE THERAPY???????
I dont understand these in any textbooks I use. Could you please explain me clearly in details what is genetic code and how to explain in nature and what are the principles of gene therapy and what is gene therapy, somatic , germ line therapy and how to distinguish them???/
Please help me sister. Waiting for your reply.
I hope someone can help SZM here, please. :)i would be more than happy to help but have a exam coming up .. and this is really long stuff.
I hope someone can help SZM here, please. :)Sorry that's too much to explain, and I have my exams too, the time is short....
Sorry that's too much to explain, and I have my exams too, the time is short....Well, her problem is mainly with the book. She says it doesn't explain well. :-\
Let her download the ann fullick active book, we have it here, or study from it if she has it.
These topics are covered there, and if she gets stuck, Google and SF are her friends.
First pic:
Gene therapy:
-to use the dna technology to overcome genetic diseases
-this is safe and ethically sound
-it is very recent and a highly experimental science
-one approach it to supply the missing gene to the body cells in such a way that it remains permanently fully functional
Distinguish between somatic and germ line therapy:
Somatic therapy
sometimes it is to supply the missing gene on a temporary bases and then to periodically re supply it.
Second pic:
germ line therapy
-it is not considered safe or ethical to attempt tamper with germ cell, cells which form gametes in the testes and ovaries this banned approach is called germ line therapy.
genetic screening:
the human genome project HGP maps the entire human genome it was started in 1990 and was achieved in 2000. the main objective was to discover the location of each human gene and the base sequence within the DNA structure.
My teacher gave me these notes, don't from where did she get them :/
@SZM try these :)
Thank you very much guMnam. May God Bless you always.no i dont have that .. but for A2 this might help .
The first and second file, I have with me. The third file is really useful. The third file is SNAB for AS Biology. Like that do you have for SNAB A2 Biology?? Please help me dear...
Waiting for your reply. :) :) :)
May someone please help me with question 6cii from the January 2009 paper:)Which Unit?
Thank you :)
How do these factors affect the rate of cooling of a body (forensics)
Humidity
Body size
And this spec point --> Discuss the way in which scientific conclusions about controversial issues, such as what actions should be taken to reduce global warming or the degree to which humans are affecting global warming, can sometimes depend on who is reaching the conclusions
Edit: another doubt :o
What is the difference between extent of decomposition and stages of sucession in terms of forensics.
Isnt it that, as the body decays, insect speices feeding on it change (sucession) :S
Thanks
Another doubt.
What actually is the acute phase of HIV.
I am confused, does it happen after HIV virus has binded with the host cell and all the viral dna thing has taken place? :S
^ In the sample paper for unit 4 there is a question which asks for named organism lined to its habitat.
and thanks for the tips. :D
I haven't got the sample paper, so can you please quote the exact question or take a snap of it?Describe a technique that you have used to study the distribution of a named organism within its habitat.
Most welcome. You remind me of the days when I was preparing for my A2 Biology exams. Good Luck!
Describe a technique that you have used to study the distribution of a named organism within its habitat.
^This one. You have to name an organism and also state its habitat.
Why are tendons inelastic?
^ that was a lot of detail :P
I have another confusion ::)
Describe how plants detect light using photoreceptors and how they respond to environmental cues.
I know the photoreceptor part but when it comes to responding to environmental cues i am confused.
Are they talking about tropisms (auxin and all that) or how phytochromes respond to the cues, e.g. germination etc. ?
^Thanks alot
Can anyone explain me Q7 b i and ii of this paper (attached)
How can we show variability on graph?
E.g. Unit 3B Sample assesment Q1 b (ii)
thanks
I understand what you mean...but..
For example, In my graph for one set of values (91, 75, 84 and 69 per 30 seconds) the mean is 159.5 beats per min, now the lowest value is 69 beats per 30 seconds. To draw the error bar, should I double 69? cause it is per 30 sec and not per min?
2ndly, I have started my graph from 150 and so the lowest value in the Set of values doesnt even fit in my graph :s ? I don't think an error bar would be that long.
Okay, massive pain in the *** question from me. HOW THE HECK DO YOU PERFORM THOSE T-TEST/Other-statistical-tests?
I just tried the one in the 2012 January paper, and understood NOTHING! I HAVE NO IDEA WHY THE VALUE OF 0.79 WAS USED INSTEAD OF THE 1.00 THE STUDENT USED, OR WHY YOU'RE SUPPOSED TO USE 7 MEANS OR ANYTHING
Can someone help me with the following, please?Yeah, I wrote the same except that instead of oil droplets I wrote lipids but I think both are acceptable.
Read through the following passage on the structure of prokaryotic cells, then write on the dotted lines the most appropriate word or words to complete the account.
Bacteria, such as Escherichia coli, are prokaryotic organisms. One of the main differences between prokaryotic cells and eukaryotic cells is that in a prokaryotic cell, the bacterial chromosome is not surrounded by a ............................................. . Prokaryotic cells store carbon compounds in the form of ............................................. and ................................................. and they may also contain one or more small circular DNA molecules, known as ................................................ . E. coli cells are motile due to the presence of a......................................................... .
(Total 5 marks)
I think the answers are: nuclear membrane, glycogen granules, oil droplets, plasmids, flagellum.
Please confirm these answers. Thanks a lot.
Maybe try to google 't-test' or look it up on Wikipedia? Maybe the number of means has something to do with how these tests are performed?
Where can I find more unit 2 papers to solve? I've solved all the 7 papers, and the specimen more than once.
Found these http://www.freeexampapers.com/past_papers.php?l=Past_Papers%2FA+Level%2FBiology%2FEdexcel+Salters+Nuffield/ (http://www.freeexampapers.com/past_papers.php?l=Past_Papers%2FA+Level%2FBiology%2FEdexcel+Salters+Nuffield/)
They were good.
Exam was great too :)
Thanks DK
I have a problem with paper 3b (paper 7)
when plotting graphs ..
how should i join the points ?
should i draw a smooth curve and ignore all points which are out of it or join the anyway ?
and some graphs look like they should be joined using a ruler .. should i join all lines or just ones that fit in .. ?
Thanks in advance :D
You don't need to know how to extract cells from blastocyst. It's about stem cells form unit 2, right? Just take cells from it. How, you don't need to know. You can check the specification for more info.thanks a lot.i was really worried
if there is anyone looking at this message please i need major help for tomorrow's AS biology 2, Dev, plants and the environment. First a link to a legit list of the specifications and please a site that can help me revise! im so worried :-\
someone please describe the totipotency in plant cells experiment.please :(You are required to know how to carry out an experiment to know if plant cells are totipotent or not.
i need the whole experiment of finding out if plant cells are totipotent or nothttps://studentforums.biz/index.php?topic=4830.0 (https://studentforums.biz/index.php?topic=4830.0)