Drake Glau Posted April 17, 2011 Report Share Posted April 17, 2011 (edited) Do a punett square and you see that 75% of the outcomes are a recombinant. Not 100% sure how they got to the 7% but I did the 75% (chance to get a recombinant since 25% are the parents genotype) and divided it by the remaining 12 outcomes and get 6.25% which is close to 7 Edited April 17, 2011 by Drake Glau Reply Link to post Share on other sites More sharing options...
iMuffinsx3 Posted April 18, 2011 Report Share Posted April 18, 2011 If a molecule of mRNA, prior to splicing or polyadenylation, has 15% A, 20% G, 30% U, and 35%C, what is the composition of the double-stranded DNA that it was transcribed from?a. 15% T, 20% C, 30% A, 35% Gb. 15% G, 20% A, 30% C, 35% Tc. 22.5% T, 22.5% A, 27.5% G, 27.5% Cd. 17.5% G, 17.5% A, 32.5% T, 32.5% Ce. 25% A, 25% C, 25% G, 25% THELP! I don't understand this question. =[The answer given is c. Reply Link to post Share on other sites More sharing options...
kiwi.at.heart Posted April 18, 2011 Report Share Posted April 18, 2011 If a molecule of mRNA, prior to splicing or polyadenylation, has 15% A, 20% G, 30% U, and 35%C, what is the composition of the double-stranded DNA that it was transcribed from?a. 15% T, 20% C, 30% A, 35% Gb. 15% G, 20% A, 30% C, 35% Tc. 22.5% T, 22.5% A, 27.5% G, 27.5% Cd. 17.5% G, 17.5% A, 32.5% T, 32.5% Ce. 25% A, 25% C, 25% G, 25% THELP! I don't understand this question. =[The answer given is c.Well first, because of complementary base pairings for every A there must be a T and vice versa and same for C and G. Using this, we know that the strand of DNA the the mRNA is transcribed from must have 15% T, 20% C, 30% A and 35% C and the other strand must have 15% A, 20% G, 30% T and 35% C. Then you can calculate the percentage for each base i.e. T:(.15+.3)/2=22.5% which results in the answer being c. 3 Reply Link to post Share on other sites More sharing options...
dufka Posted April 20, 2011 Report Share Posted April 20, 2011 Can anyone explain it in simple terms?I know that it is a shift to the right in the graph of partial pressure but i dont understand why actually this shift happens.. please help me..;( Reply Link to post Share on other sites More sharing options...
Mahuta ♥ Posted April 20, 2011 Author Report Share Posted April 20, 2011 Hello, this question was answered before. Hope it helps, if not let me know which part you don't understand.Bohr Shift 1 Reply Link to post Share on other sites More sharing options...
IBavictim Posted April 23, 2011 Report Share Posted April 23, 2011 Hi! I have a very quick question that I'll post here since I don't think I really need to make another topic thread just to ask it I have my internal assessment mark for Bio HL from my teacher and ended up with a 5 (I really thought I'd get a 6! I now regret being so lazy about my lab write ups! ) haha lately I've been begging the May 2012 candidates to work hard on their labs lol!Anyways, is it still possible to end up with a 6 ...or maybe a 7 if I really try for the exams?I would understand it if you tell me straight up that I won't get a 7 so I don't hope for one! I'm aiming more for a 6 now...but if a 7 is possible, I'd work twice as hard ! Reply Link to post Share on other sites More sharing options...
Drake Glau Posted April 23, 2011 Report Share Posted April 23, 2011 (edited) It's possible you might still get a six on your IA stuff. They can be moderated up and down (yes that means you could get a 4 also) but yes, a 6 is very possible and a 7 is if you completely BEAST both all three paper1 2 and 3 Edited April 23, 2011 by Drake Glau 1 Reply Link to post Share on other sites More sharing options...
nuka Posted April 23, 2011 Report Share Posted April 23, 2011 Also, do you happen to know a great resource for the Options part of the syllabus? My teacher said we only need to learn E-H For HL IB Biology you actually only need to know 2 options, of your choice So E-H is a bit of overkill!Best resource (IMO) is the syllabus + a good IB textbook e.g. the Allot & Allot Course Companion for Biology.2. . .options..? You see, I was never told that ! O.OI have been trying to drill them in my head and I could only remember E AND H! (I can't believe I'm so happy about a tiny thing!!) maybe your teacher meant option E and option H.. yeah, otherwise doing so much would be extremely difficult to do.try click4biology anyways, for any bio help. it's a great link Reply Link to post Share on other sites More sharing options...
nuka Posted April 23, 2011 Report Share Posted April 23, 2011 anyone know where i can get help for theoretical genetics? i get stuck with that unit every single time, the standard and higher stuff. all of it. Reply Link to post Share on other sites More sharing options...
Mahuta ♥ Posted April 28, 2011 Author Report Share Posted April 28, 2011 Hmm, why didn't I see this before.Anyways, I am not sure really, but you can ask if you need something explained. Genetics wans't my best one but I have done some in uni and may be able to help. Reply Link to post Share on other sites More sharing options...
Drake Glau Posted April 29, 2011 Report Share Posted April 29, 2011 (edited) I've never heard of "theoretical genetics" unless there's another name IB gave to it. And I'm pretty sure I'm 100% current on the objectives list =/If IB has another name for it I might be able to help if you know the other name Oh, it's that stuff, thanks inm. And yea...easier to help if you know what you need help on instead of the whole section. Edited April 29, 2011 by Drake Glau Reply Link to post Share on other sites More sharing options...
ILM Posted April 29, 2011 Report Share Posted April 29, 2011 Wait i think there is something called "theoretical genetics" it is the lesson 4.3 in Core topics, and i am willing to help if you specify the thing that you don't understand. Reply Link to post Share on other sites More sharing options...
elmar Posted May 1, 2011 Report Share Posted May 1, 2011 Does anyone know if the following Dichotomous key is sufficent for the syllablus:5.5.5 Apply and design a key for a group of up to eight organisms. Credit to http://ua-ib-bio.tumblr.com/ Reply Link to post Share on other sites More sharing options...
Drake Glau Posted May 2, 2011 Report Share Posted May 2, 2011 (edited) Does anyone know if the following Dichotomous key is sufficent for the syllablus:5.5.5 Apply and design a key for a group of up to eight organisms. Credit to http://ua-ib-bio.tumblr.com/If that is EXACTLY what you would create, no. Keys are a yes or no system, not a this or that system.Organism is nocturnal OR organism is not nocturnal<-goodOrganism is nocturnal OR organism has webbed feet<-bad"has feathers"/"does not have feathers""does not have feathers"->"has legs"/"does not have legs""has legs"->"lizard""does not have legs"->snake"has feathers"->"swims"/"does not swim""swims"->duck"does not swim"->henHonestly, not to be a jerk, you're key needs more steps, like 8 steps. And you need to use scientific names. Here's an amazing example (it's candy, but you get the point )http://mrsmaine.wikispaces.com/file/view/candy_class._key.jpg/49552245/candy_class._key.jpgWOW, that was big, use the link...not going to insert that big of an image Edited May 2, 2011 by Drake Glau Reply Link to post Share on other sites More sharing options...
timmotytimmoty Posted May 4, 2011 Report Share Posted May 4, 2011 Explain how meiosis can result in genetic variety Can anyone answer this question? It is for 8 points! Thanks! Reply Link to post Share on other sites More sharing options...
Licorice Posted May 5, 2011 Report Share Posted May 5, 2011 Hi guys! I was just wondering if anyone knows what the difference between these assessment statements are:2.5.4Describe the events that occur in the four phases of mitosis (prophase, metaphase, anaphase and telophase (2).2.5.5Explain how mitosis produces two genetically identical nuclei (3).In the second one, aren't we just supposed to describe exactly that which is stated in the first one, i.e. the four phases of mitosis? Reply Link to post Share on other sites More sharing options...
ILM Posted May 5, 2011 Report Share Posted May 5, 2011 I am with you, that some assessment statement looks alike.1- Describe means to "give a detailed account', in that you will describe the process, e.g in Metaphase chromatids line up, etc...2- Explain means to "Give a detailed account of causes, reasons or mechanisms", in that you will expalin how the process cause a identical nuclei additional information should be there, e.g the spindle fibers will assure that each cell has the same set of DNA, or DNA replication happens because each set should have the same set of 46 chromosomes , etc...Hope that it was helpful 1 Reply Link to post Share on other sites More sharing options...
Mahuta ♥ Posted May 5, 2011 Author Report Share Posted May 5, 2011 *TOPIC 2 (2.5.5)--*how mitosis produces two genetically identical nuclei*2.5.4:Yes the whole process of mitosis.2.5.5:You're supposed to know the exact steps that actually enhance the production of two genetically identical nuclei.It would be for a question like:What ensures that mitosis produces two genetically identical nuclei? One of each of the 23 types of chromosome is pulled to each pole of the cell by the spindle microtubules.Half of the chromosomes are pulled to each centriole by mesosomes.Identical chromatids are pulled to opposite poles by spindle microtubules.DNA molecules are moved to the equator of the cell where they are replicated.Basically which steps characterizes mitosis as a process that produces two genetically identical nuclei, if that makes any sense? 1 Reply Link to post Share on other sites More sharing options...
Licorice Posted May 5, 2011 Report Share Posted May 5, 2011 I still think they are somewhat similar , but what you guys explained kind of makes sense! Thanks a lot inm and Mahuta Reply Link to post Share on other sites More sharing options...
Mahuta ♥ Posted May 5, 2011 Author Report Share Posted May 5, 2011 No they're not, for example in 2.5.4 you're going to mention things like "chromatin condenses together into a chromosome". However, that has got nothing to do with the fact that mitosis produces two genetically identical nuclei. What ensures that is the fact that sister chromatids (i.e the other copy of the DNA that was replicated in interphase) are pulled apart so that each one goes into a cell, which is what happens with all 23 chromosomes. By the end of Anaphase, you have a copy of each chromosome on each pole of the cell. That's what produces two genetically identical nuclei from mitosis. Yes it looks the same, but in the second one they are only looking for the part where sister chromatids are seperated. 1 Reply Link to post Share on other sites More sharing options...
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