grayfalcon89

I just learned about five kinds (maybe there are more but I only learned 5) and I want to be assured that what I know is correct. The first one is random gentetic drift which frequency of an allele of gene varies from time to time by random. No one allele dominates over another completely. The second one is natural selection ---survival of fittest--- which is the animal or allele that best adapts the environment survives. The third one is artificial selection such that humans picking the horses to breed for the race. This is not the one who best survives on the environment determined by nature but rather humans, who wants to have "best" allele and manipulates over it. The fourth one is founder's effect where out of many various alleles, the allele with small population, say allele that gives you 6 fingers (if there are only two people with 6 fingers on the room of 50 people with 44 that has 5 fingers) and starts out new population. The descendents of the population are same from founders. Ex. Amish in US The fifth is bottlenecks which are similar to founder's effect except instead of one allele or two moving out, in bottleneck, only one or two survives and rest of them dies. So, the descendents coming out on the next generations are same to the ones who survived. Are they right?

Recently (actually today about 5 minute ago), I read an article from Discover August 2005. Basically, the article suggested that the intermarriage, or marriage between cousins, isn't exactly what most people think. Like it's explaining no one really "like" intermarriage but from genetics, the prejudice that people have on intermarriage such as "if you marry your cousin, your baby will have 9 heads" are not true. Maybe that example is obviously wrong since it's probably impossible to have a baby with 9 heads. But my point is, what do you think about the intermarriage? I personally go against it but like after reading this article, there isn't necessarily any wrong with it. I mean, before we had car and other mobiles that helped us on the movement, most people say the family has last name of AHHHHHH, would marry with AHHHHHH because AHHHHHHH is the only family member you can find. Any respond is great. It would be more better if we can get into some based-on fact discussions.

I have a trouble getting the answer to this question. There are two parts to it. I answered the first one but I can't get the second part. If the 3rd DNA base in your gene for insulin was mistakenly duplicated -- meaning another copy of that letter were placed between the current 3rd and 4th base --what type of mutation would that be? Ok. That was the first part. I put "frameshift mutation" because it changes the codon of the DNA. How it is going to be readed changes because of the copy placed. Using the first question, here is a question that I DID NOT get: If the event above actually occurred, what would be the first three amino acids in the protein? I have no clue how to do this. The insulin that I made was like this: I don't have a codon of DNA. But I have RNA codon. It was, at least first 9 letters were: GGGAUAGUG When this is read to code for the protein, it became: CCCTATCAC But how does this help me answering my question?? Please give good help, thank you!!!

Hi, I'm doing a research on Testicular Cancer but it seems that I can't find exact correct information on it with diagrams. I tried many googlings (maybe I was missing something but) but still, I couldn't find much good informations. If you know good site or pictures, please post here. Thank you very much.

Yes. You can find it without using Heron's Formula or Law of Cosine I belive.

Hi, I need quick help on understanding transcription and translation. I think I know what transcription is and maybe translation is but here is what I think they are: In transcription, DNA's replication that in which RNA involves. This means that instead of DNA replicating the same thing, RNA gets involved and RNA is made, which has antisequence of DNA. Suppose DNA is ACG then RNA is UGC. By the way, thymine is replaced with uracil in RNA. In translation, decoding RNA messages into polypeptide chain, or simply, rewriting in protein. But my question is, what does transfer RNA do? I know that messenger RNA carries out the information for DNA around the cell and this is what basically happens in transcription, right? But why is transfer RNA needed in here for translation? My book quotes: Why is it complementary to messenger RNA? Perhaps this is like asking why RNA complementary to DNA? I can answer that question because RNA goes in place of another DNA so in order for them to match, they have to be complementary or antisequence of DNA. But why is in this case of messenger RNA and transfer RNA? Like why can't transfer RNA takes exact form of messenger RNA and just go to where codes of amino acids are and decode it? Perhaps this might help so i'll put also: No clue at all. Thanks for the help.

Just confirmation: Mitosis consists of four steps Prophase - Where DNA's getting packed Metaphase - Where DNA's beginning to cluster in the center Anaphase - Where cells start the separation. Telephase - Where cell is completely divided into two cells, each with one complete set of DNA. And there is this Interphase, where it is between Telephase and Prophase, where normal cell function occurs and DNA is replicated. Also, X-shaped (even Y-shaped) are made up of two identical parts called chromatids. Each chromatid is a complete set of DNA. In the center is that circly thing called Centromere that joins two. On that Centromere is those spikes call the Kinetochore. I'm not sure about last part. So, help me on this please!

This was a problem from my school. I think I'm pretty sure that I'm right but I just want to be sure. Say there's this guy named Bob with hemophilia. He marries with a woman named Cathy and they have six children, three of them are daughters and three of them are sons. None of them has hemophilia. The daughters, in order from their age, are Jessica, Ellie, and Lauren. Jessica marries with a guy and have two sons with hemophilia and two daughters with no hemophilia. Ellie also marries with a guy and have one son who is also hemophilia. Lauren marries with a guy and among their four children, she has one son with hemophilia and three daughters who are healthy. Bob and Cathy's sons also marry and have children and but none of their children has hemophilia. Questions: Is the trait sex-linked or autosomal? And is it dominant or recessive? In my opinion, because that Bob has hemophilia but none of his children has any and only his grandsons from their daughter has hemophilia, this trait is sex-linked. Of course, hemophilia is a sex-linked trait anyway. But is it dominant or recessive? Well, it is recessive because say, it's dominant then the daughters who would receive the dominant traits from their father and recessive one from their mother would be also affected. But this is not the case here so it has to be recessive.

Evaluate: [math]\sum^{49}_{k=1} (-1)^{k} \binom {99}{2k}[/math] Figure this out without using calculator at all.

Ok. The two things as titles are confusing me. Both are the traits, right? And both were also influenced by genes. But I don't understand what is their major difference. Like colorblindness is an example of sex-linked while baldness is sex-influenced.

Oh, I see. Thanks now. And I see why the bloodtype has no effect on it --> the SCA is caused by substitution of nucleotide of the polypeptide which doesn't matter on the person's bloodtype.

Just wondered because I thought it could be friends to the following signs: Thanks to [math]\LaTeX[/math] of course! [math]\alpha\\ \beta \gama \theta[/math] Theta especially resembles zero and 8.

This is sort of stupid questions that I learned this before but I can't remember now. What is exactly difference between the mitosis and meiosis? I know that the mitosis is the division of the two nuclei but when I got to the part of the chromatin, I got lost. What is the DNA double helix and how this differ from chromosome itself? Also, from the cell cycle, I see the word interphase. There are three part, G_1, S, and G_2. What is the difference between each step? Appreciated greatly. Happy New Year!

[math]\infty[/math] See this shape and turn it in clockwise for 90 degrees. It looks like 8.

Everytime I see number 8, this number reminds me of sign infinity. I wonder among all the numbers exists in world, why was the number 8 created as shape of infinity. Maybe there is no reason but this seems interesting.

I'm kind of confused. I'm just new to the biology in my high school so my class only got to the part about blood types A,B, O, AB with RH+ and RH-. Can you translate that into the words I can read and understand? I really would appreciate it. I DID try to read it but it's just not easy

According to what I read, the sickle cell anemia is caused by substitution of one nucleotide and it is common on Africa and Asia, especially to African people because of resistance to malaria. I'm not sure I understood what that means. I'll add the quote from the book. Also, does this relate to the person's bloodtype also? Maybe this isn't too smart question but does the Landsteiner's bloodtype (which is just another name for common bloodtypes, A,B, AB, and O), influence to the person's bloodtype? Thanks for the replies. Happy Holidays

Since this is a science forum, anyone know well-known science competition? I know Westing-Siemens House but that's sometime away from me now. Thanks. Happy Holidays.

I have few questions for the genetics. This thread can be posted on the general biology forum but especially this part is genetics, so I'm putting here I just hope it's not too easy concept if this forum only talks about complicate genetics Question that I didn't understand. You plant 50 yellow peas which were grown on a tall plant. When the plants mature, 28 are tall with yellow seeds; 8 are tall with green seeds. How mnay plants would you expect to be short with yellow seeds and how many would be short plants with green seeds? [math]\text{Only thing I just assumed was that the genotype of the parent} [/math] [math]\text {Which would be TtYy. The reason is that there are both}[/math] [math]\text {Both recessive and dominant traits} [/math]. [math]\text {But my question is, how do you determine the genotype here?}[/math] And after that, I don't know what's the answer is nor do I know what should I do... Questions that I did but I'm not confident [math]\bigstar[/math] indicates the questions. [math]\bigstar[/math]A hetreozygous yellow-seeded pea plant is crossed with a homozygous green-seeded pea plant. One of the offspring produces yellow seeds. What is the correct genotype of the offspring? Yy*yy = Yy, Yy(2), yy. So, in order for offspring to be yellow, it has to be yy so that's our answer. [math]\bigstar[/math]A heterozygous yellow-seeded pea plant is crossed with a homozgyous green-seeded pea plant. There are 60 seeds produced. When these are planted, how many of the plants do you expect to produce green seeds? By Yy*yy = Yy(2) and yy(2), this basically shows that green are going to be 30, which is 1/2 of 60. Next three questions, in my opinion, seem all same. Maybe I'm wrong though. [math]\Rightarrow \bigstar[/math] [math]\bigstar[/math]In humans, the ability to roll your tongue is controlled by one gene. A couple who can both roll their tongue has a son who cannot roll his tongue. What is the dominant version of the trait? What is the recessive version of the trait? What is the genotype of the father? mother? son? Roll the tongue - dominant Can't roll the tongue - recessive How? Pedigree result like: ~[]-() ~~|~ ~[*]~ [] = male with no trait () = female with no shading [*] = son with shading Both parents are thus, heterozygous or if the letter is used, Rr (Roll the tongue for R) and son is rr. [math]\bigstar[/math]Some people have hairlines which are straight across the top of their forehead. Other people have what is called a widow's peak, a point in the center of the forehead where the hairline is lower than on either side. What is the dominant version of the trait? What is the recessive version of the trait? What is the genotype of the father? mother? daughter? In case that question and one I'm going to post now is same, let me just put them together. [math]\bigstar[/math]When placing your hands together, you either normally place your left thumb over your right, or your right thumb over your left, based on a single gene. A couple who both pace left over right have a daughter who places right over left. What is the dominant version of the trait? What is the recessive version of the trait? What is the genotype of the father? mother? daughter? First one - Peak = dominant, straight = recessive; father and mother = heterozygous; daugher = recessive Second one - Left over right = dominant, right over left = recessive; father and mother = heterozygous; daughter = recessive I got these problems from the extra worksheet so they'ren't homework (that's why it's here instead of homework forum) but I'm doing this so I can understand the concept better.

THANK YOU! But just that on the last part, both parents CAN"T be heterozygous because one of them in nonshading, meaning no traits so it has to be homozygous recessive or it would look like its husband.

Ok. This isn't too good question but here, how about this case? It can be dominant because dominant and recessive will have dominant offspring on no matter what. But those can also be recessive if the parent of the no trait is heterozygous and then, there will be a chance of offspring being recessive. That's what I put for the answer. I know the dominant is a "sure" answer and recessive is "only in a special occasion" answer but still, I'm sort of confuse when I'm determing the trait is dominant or recessive.

Prove that any five consecutive integer is divisible by 5 such that the least term is > 0. Prove that any two integer's sum is NOT always divisible by 3. State why this is and tell in what case is this possible. Prove that: [math]\binom {n}{k}[/math] equals [math]\binom {n}{n-k}[/math]

Oh. Yea, I always have that probability in my head. I shouldn't look that way on pedigree. Punnett Square only gives a probabliity, not necessarily what the true will be.

Another question. Tell me if it's wrong. This trait (the shading) is recessive. Here is why. On the bottom, if the parents who are nonshading are recessive, they can't have children who are dominant because recessive-recessive only gives you dominant. I can go for saying recessive is answer and explaining but I think that's enough to declare dominant nonanswer is enough since there are only two choices.

Thanks for the reply. Then application question: If the diagram below shows the pedigree of family of JackColson (cool name!) then is the trait that is shown there a dominant or recessive? * means shading. + means no shading. ~ is used to fill out the empty spaces. - is used to donate marriage. ________ is children. ~~~~~~~~~~[*]-(+)~~~~~~~~ ~~~~~~~~~~~~|~~~~~~~~~~ ~~~~~~~~~______________~~~ ~~~~~~~~(+)-[*]~(+)~~~[+]-(+)~~ ~~~~~~~~~~|~~~~~~~~~~|~~~ ~~~~~~~~_________~~~~______ ~~~~~~~~[*]~(*)~[+]~~~[+]~(+) I think this case is impossible. The reason is that if it's dominant, the nonshading is recessive. On the right generation of the third level, that makes sense pretty okay. recessive-recessive has offsprint of recessive. But comparing the third generation on the left and one on the top, there occurs some weird thing. Since the first generation has two recessive as the offspring, it automatically states that the one of alleles of the parent on the top has recessive trait and since the totally, it's dominant, the parent is heterozygous. Because another parent is recessive and to be recessive, you have to have recessive only, it became obvious that the offspring on the second generation that's dominant is also heterozygous. Now, here comes the part that doesn't make sense. The one that's marrying with the second generation dominant is recessive and this is exactly same case with the one on the top where the guy is dominant and woman is recessive that guy is heterozygous. On the top, however, there were only one offspring with dominant trait. But on the bottom, there occur two recessive trait. So, this proves that this is impossible case. Let's look at the case where the shading is recessive. If it's recessive, then the other parent that it's marrying is heterozygous dominant (nonshaded) because there are one recessive offpring. That explains that the offspring is recessive. Now, this offspring who is recessive marries with the woman who is dominant. Since there is at least one recessive offspring, the genotype is heterozygous (for woman). Yet, here comes the nonmaking sense part. This case is again same as one above. But on the top, there were only one recessive. On the bottom, there were two recessive which can't be possible. Thus, this case is impossible. I'm getting this pedigree now.. But I need more practices I think..