What does Dominant and Recessive mean in terms of genetics, and how do punnett squares work?
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.
639406
When Mendel began to scientifically analyze "heredity", he concluded that each parent (mother + father) donates an "allele" for a characteristic (trait) in question.\n\nA lettering system was used: Capital letters indicated that the allele is DOMINANT; lower-case letters indicate that the allele is RECESSIVE.  This is the case for 22 of the 23 chromosome pairs in humans.  The 23rd pair are called the sex chromosomes.  Females (mother) always donate an "X" allele; fathers can donate either an "X" or a "Y" allele.\n\nIf a person's genotype for their sex is "XX", this means two things.  1: Both X's are the same (in other words, X and X are identical).  Identical alleles are called HOMOZYGOUS.  2: A human who is "XX" is female.\n\nA human who is "XY" is male.  "X" allele and "Y" allele are DIFFERENT.  Thus, they called HETEROZYGOUS.  We refer to men as being "heterozygous" in that a male's SEX alleles, 'X' and 'Y' are different.\n\nLet us say "B" is the dominant allele for brown eyes, and "b" is the recessive allele that can result in blue eyes.  A person who is "Bb" is heterozygous (B is a different allele than b).  A person's who genotype is Bb is likely to have brown eyes.  A person who is "BB" is HOMOZYGOUS (1st B is identical to the 2nd B) and will definitely have brown eyes.  A person who is "bb" is HOMOZYGOUS (1st allele 'b' is identical to the 2nd allele, 'b') for the recessive allele; this person will have blue eyes.
113257
The 2 genes are rather called alleles which means different forms of the same gene. One allele is dominant and the other one is recessive. The one that is expressed is the dominant one and the hidden one is recessive. The organism is said to be heterozygous or hybrid.
725772
A homozygote's cells are diploid or polyploid and have the same alleles at a locus (position) on homologous chromosomes. When an organism is referred to as being homozygous for a specific gene, it means that it carries two identical copies of that gene for a given trait on the two corresponding chromosomes (e.g., the genotype is AA or aa). Such a cell or such an organism is called a homozygote.\n\nA homozygous dominant genotype occurs when a particular locus has two copies of the dominant allele (e.g., AA). A homozygous recessive genotype occurs when a particular locus has two copies of the recessive allele (e.g., aa). This can occur when both parents carry at least one copy of the allele.\n\nPut simply: Homozygous is just having two of the same alleles.
956460
To start with, You need more information as to the Parental genotype for each question, \nFor example in question (a) since you have only mentioned full dominance, we can either assume both parents will be A/A x A/A. However this cross is useless because you know there will not be variation in the F1 progeny because both are dominant. thus the ratio is 100% all dominant A/A.\nThe second assumption is to cross a dominant parent A/A with a recessive parent a/a. If that's the case then you choose one gamete from each parent to form the F1 as follow\n\nParental Genotype        A/A    x    a/a\nGametes                          A     x    a\n\nF1                                         A/a\n\nfrom here, if you need to get genotype and phenotype ratio for your F2, you need information as to what kind of cross you want do. You can self the F1 or you can testcross with a recessive parent. In either case the ratio is different\n\nSelf-cross                  A/a    x      A/a\nGametes              1/2 A , 1/2 a    x   1/2 A , 1/2 a\n\nF2  punnet square\n..............1/2  A..........1/2 a\n\n1/2 A......1/4 A/A........1/4 A/a\n\n1/2 a.......1/4 A/a........1/4 a/a\n\nPhenotypic ratio of F2:  1/4 A/A; 2/4 A/a; 1/4 a/a = 1:2:1\nGenotypic ratio of F2:  (1/4 A/A + 2/4 A/a); 1/4 a/a = 3:1\n\n\n\nTest-cross                  A/a    x      a/a\nGametes              1/2 A , 1/2 a    x   1/2 a , 1/2 a\n\nF2  punnet square\n..............1/2  A..........1/2 a\n\n1/2 a......1/4 A/a........1/4 a/a\n\n1/2 a.......1/4 A/a.......1/4 a/a\n\nPhenotypic ratio of F2:  1/2 A/a; 1/2 a/a = 1:1\nGenotypic ratio of F2: same as genotypic ratio\n\nquestion (a) is not formulated in a clear way. for example. question (a) should have mentioned something like this:\n\na) The F2 of monohybrid cross with both parents full dominance, or 1 parent full dominance, 1 parent recessive.\n\nIs hard to work in genetics problems when the problem lacks crucial information. let me know if there is more information that you did not write down on your question.
952198
Recessive genetic traits
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.
875716
probably none, but its depends on which parents genes are more dominant
1024331
I apologize but all that i can come up with is one.\n\nYou could raise fruit flies (Drosphila) and relate them to Gentics. i.e. punnet sqaures, Gregory Mendel, common characteristics, principle of dominance and recessiveness, etc.\n\nif you would like me to go further into detail about this project, please e-mail me at \n\nthe_lonley_kender@yahoo.com or send me an IM on Yahoo! at the_lonley_kender or on AIM at  thelonleykender
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.
149035
I assume you asked about autosomal incomplete dominant.  Generally speaking, let's say R is dominant allele for red color and r is the recessive allele for white color.  Incomplete dominant means that when parents RR and rr have offspring Rr, their color will be pink instead of red or white.  It's different from co-dominant which you can use the ABO blood type as an example with people who have AB blood type as an example of codominant.
296412
First of all you have to find out if your dominant trait (white coat) is homozygous (WW) or heterozygous (Ww). Your recessive trait has to be (ww)(b/c both alleles must be recessive in order for the black coat to be expressed.) After you find this out you can use a Punnett Square to plug in your information and find the outcome. This site will step you through drawing a punnett square step by step. http://www.borg.com/~lubehawk/psquare.htm
142636
Genotype are the genes present in the DNA of an organism that determine that organism's traits. Each genotype is referenced with two similar letters - one capital one lower case. This means that there are three possible combinations, e.g. BB or Bb or bb. The capital letter represents the dominant gene and the lowercase the recessive gene. So each offspring gets a gene which is a combination of those passed down from its parents. By way of example, lets look at the size of your nose. Your Dad has a big nose with genotype Bb and your Mum has a small nose with genotype bb. If your Dad passes down the B and your Mum the b then you will have a big nose (Bb) because the B will dominate the b. But if they both pass down the b (bb) then you will have a small nose. If you get bb then that is called homosygous (pure) genotype and if you get Bb that is called hetrozygous (hybrid) genotype. The reason it is sometimes possible for a child to look nothing like either of their parents is that if both parents are hybrid genotypes (eg. in the nose example both are Bb and therefore both have big noses) all three combinations (BB, Bb or bb) are possible and you may get the bb and have a small nose...
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.
819765
Just do a few different Punnet Squares.  Once you find the one with the right proportions, you're golden.\n\nOr you could reason that since the long hair allele is recessive, and the parents are short-haired, both parents must carry the long hair allele.  Meaning they would each have one of both alleles.
761641
Ss and Ss\n\nGenotype of both parents are heterozygous. If you draw out the Punnet square, you see 1/4 of the offspring will have long hair while 3/4 will have short hair. The phenotypic ratio of long hair to short hair ends up being 1:3, just like the puppies are 2:6.\n\nGenotype ratio ends up being:\n1/2 heterozygous Ss\n1/4 homozygous dominant SS\n1/4 homozygous recessive ss\n\nHope this helps.
515090
dominant e.g. Aa, AA - Recessive -aa