I need to know what the Principal of Dominance and Recessiveness is. It's for biology, and i really need help!
374887
Very simply put, dominance and recessiveness are characteristics of genes.\n\nA dominant gene is expressed (shows up visibly in the offspring) when only one copy of the gene is present, on one chromosome from one parent. Let's say Tallness is a Dominant gene. If you have ONE tall parent, and get ONE copy of the Tall gene, you will probably be tall. If your tall parent was the son or daughter of a TALL and a SHORT person, they may only have ONE copy of that gene. If you get both SHORT chromosomes from Mom and DAD, you will NOT be tall. So you have 50 to 100 chance of being tall with a Dominant gene.\n\nNow, let's take the gene for BLUE eyes. It is recessive. You need TWO copies of this gene to get blue eyes. If Mom has blue eyes and Dad has blue eyes, and you get copies of both blue eye genes, you will have blue eyes. But if Mom has blue eyes, and Dad has brown eyes, you might end up with Brown eyes. Don't that make your blue eyes brown, so to speak.\n\nBUT..if Dad's mom had blue eyes and Dad's dad brown (your grandparents) and if Dad has one blue eye gene and one brown eye gene and has brown eyes AND if your Mom still has those blue peepers, you have a 1/4 chance of ending up with one blue eyed gene from AND a blue eyed gene from Dad and you will also have blue eyes like your Mum. Don't that make your brown eyes...blue?
708035
I can only answer number one.\nThe possible traits can be determined.  But there's no way of know the exact traits of the offspring unless the parents have either two dominate or two recessive genes with every specif trait.  For instance, using punnett square:\n \n----d----d\nD  Dd Dd\nD  Dd Dd\n\nAll the possible genotypes are the same.\nSorry I couldn't answer your other questions!
830750
1. heterozygous: Punnett square is Pp x pp\n2. dominant b/c if it was recessive that would be the only type of allele the parents would pass on and all their children would have to be intensely freckled\n3. the Punnett square would be a 4x4 box with the B's and C's independant of each other. so on one side you have BC, Bc, bC, and bc with all of those showing up on the other side as well b/c the female was the same genotype as the male.  Obviously the black color is dominant b'c the male is heterozygous and black so all heterozygous offspring and all homozygous dominant offspring will be black as well.  the question gets a little fuzzy here though, i think you may have left some out b/c we don't know which of the two genes controls color or if they both do how the interaction between them works.  I'd be glad to help further if you have any more information to supply.
560142
One of each pair is derived from either parents. Also due to the diploid nature of chromosomes genotypes as homozygous dominant, homozygous recessive and heterozygous can be found. Thus a recessive character can be avoided to the maximum.
109654
http://opbs.okstate.edu/~melcher/mg/MGW2/MG2443.html\nhttp://mendel.biol.mu.edu/faculty/munroe.html\nhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=9841677\n\nit's a bit complicated to try to explain so i hope these sites help
842615
Your question requires more knowledge of science and genetics than I have.  However, since you haven't received much help with it I thought I would give you a couple of sites.  Try these - they may be of some help to you.  Sorry I couldn't help more.
1024670
I'd suggest you look in the front of your textbook.  It will be along the lines of "The principles of biology are. . . ."  Usually when they ask open ended questions like these they don't want a thoughtful and insightful answer like the ones given above but rather, for you to parrot the aforementioned sentence back to them.
922905
There really is no essential difference in the way\nthe genes are inherited.  The difference is in how\nthey affect the offspring.  In polygenic inheritance\nthere are many gene pairs involved, each of which\nhas a small effect and the effects of each pair are\nadditive with the others.  Such genes control things\nlike height, weight, skin color, etc.  The genes in\nwhat is usually called Mendelian inheritance have a\nlarger and more noticeable effect.  Actually the\nexamples given in biology courses are usually\nover simplified.  The case of eye color is a good\nexample.  What is usually taught is that brown eyes\nare dominant and blue eyes recessive, but this is\ntrue only if all other things are equal, that is, there\nare no other genes affecting eye color to interfere.\nIn the fruit fly there are dozens of gene pairs that\naffect eye color, and probably as many in human\nbeings.  My father had blue eyes, my mother has\nbrown eyes.  I have never been able to decide\nwhat color my eyes are.  They are sort of blue\naround the edges, yellow more toward the center,\nwith a reddish brown spot in one of them.  Also\nwhat about eyes that are described as green, gray\nhazel, violet?
166266
The gene that'll mask a recessive one is called as Dominant gene. \nEx: \n  The genes responsible for the tallness of Pea plant are \nT & t.\nT= Dominant gene.\nt= Recessive gene.\nPresence of one T gene makes the plant to be taller.
986313
T-dominant- means no tay-sachs\nt-recessive- tay sachs\n\nto have Tay Sachs you must have 2 recessive alleles so tt (this is homozygous)\nThe only way the parents could have a child with tay sachs is for both to be heterozygous for tay sachs which means Tt.\n\nYour punnent square would look like this:\n\nMom goes across and dad goes down\n\nMom-T    t\n''''''''''''_________\nD  T  I  TT I  Tt  I\nA---------------------              \nD  t  I  Tt    I  tt    I\n------------------------\n\nTo do a punnent square you write out one parent's alleles across the top and the other along the side.  Then in each box you write the alleles that are mix in each box.  You can see that the parents would produce in the first box TT which means that person is homozygous (both the same) (also since both capitols would never pass on tay sachs).   The second box across Tt which is heterozygous.  We call this person a carrier.  A carrier is someone who does NOT have tay sachs, but can give it to someone else.  The first box in the second row is Tt too.  A carrier as well.  The second box in the second row is tt.  This is homozygous again, but since a lower case t represents tay sachs this person has it.  \nSo there are 4 boxes.  1/4 of the time TT- no tay sachs\n                                     2/4 of the time Tt-carrier but no tay sachs\n                             and  1/4 of the time tt-tay sachs\n\n1 divided by 4 is .25 which is 25%.  \nThese parents have a 25% chance of having another child with Tay sachs.\n\nSorry about the punnent sq. I couldn't get it to draw right.
706626
When it states the frequency of the dominant allele in a population, think of p as one allele that 36% of the population is carrying. so, we can set p=36%, or .36\n\nThe next part of the problem asks for the frequency not of the recessive allele, but of the recessive trait. In order to carry the recessive trait, the person must have both alleles. The probability that both parents passed down the allele for the person to have the trait, using the multiplicative rule of probability would be q*q. We are solving for q^2 since we are looking for the trait not the allele. \n\n1-p=q\n1-.36=.64\nq*q=.64*.64=0.4096\n0.4096*100%=40.96%
813775
Monohybrid inheritance is the inheritance of a single characteristic. The different forms of the characteristic are usually controlled by different alleles of the same gene. For example, a monohybrid cross between two pure-breeding plants (homozygous for their respective traits), one with yellow seeds and one with green seeds, would be expected to produce an F1 (first) generation with only yellow seeds because the allele for yellow seeds is dominant to that of green.\n\nSource:\nhttp://en.wikipedia.org/wiki/Monohybrid
192005
Incomplete dominance refers to the situation where a gene has 2 alleles that are equally dominant. There is not a dominant and a recessive gene. Furthermore in incomplete dominance, when both dominant alleles are present in the chromosomes, neither will show up; instead you get a blend of both characteristics. For example in the four o'clock flower, the petal colors white and red exhibit the condition of incomplete dominance. When both white and red alleles are prseent, the result is a pink flower; pink of course being a blend between red and white.
918396
No, it depends on which form of the gene (dom or rec) is more advantageous.  For example, having 10 fingers and 10 toes is recessive.  12 fingers and 12 toes is dominant but you see it rarely.  Just because something is dominant doesn't mean it will show up more often, it's just more easily expressed.
251834
mendel tested genes in peas. he cross bred smooth and wrinkled peas and found that all the offspring grew smooth. then he bred the offspring and they grew some smooth and some wrikled at a ratio of 3:1.\nthis maade him think about dominance, in this case, the smooth allele was dominant to the wrinkled allele. he also did work on smooth gen peas and wrinkled yellow peas. When he bred these, he found a ratio of 9(sreen smooth):3(green wrinlked):3(yellow smooth):1(yellow winkled). this showeed him that the green and smooth alleles were dominant to yellow and wrinkled.\nhe deided that the rules of breeding ratios would either be 9:3:3:1,3:1,2:1, or 1:1 when dealing with dominance
809919
There has to be more info than that!\n\nThe only possible explanation I can give would be if you blue kernals with red kernals.  If mixed, they could produce purple.  The parent kernals could have a mix of dominant and recessive blue and red traits and still produce purple.
960310
A dominant trait is one that only needs one allele to be expressed in the phenotype. For example:\nIf R is the allele for green eyes and r is the allele for brown eyes, then a person would only need one R to get green eyes (which would make green the dominant trait) while you would need two r's to get brown (making it recessive).\nI can't put the punnet square here but if you take a look at the source site, you'll see what one looks like. \n\nSo in this case, you would have green eyes most of the time as R is expressed 3/4 times (or 75% of the time), while rr is only expressed 1/4 times (or 25%)\n\nI hope this makes sense! I gave a reference for the punnet square.