are dominant phenotypes alwayes the most common in a population? explain, but pls to fast iam waiting?
930003
Nope.  All of the previous answers are right.
4001
Blood types are not evenly distributed throughout the human population. There are also variations in blood-type distribution within human subpopulations. The figures given here are for people of European descent:\n\nType Frequency\nO+ 38%\nA+ 34%\nB+ 9%\nO- 7%\nA- 6%\nAB+ 3%\nB- 2%\nAB- 1%\n\nTherefore, O+ is the most common and AB- is the rarest.
821121
Because dominant mutations will be selected against.  Keep in mind for all dominant mutations, a phenotype will be expressed, and in a lot of these cases, the gene may not be passed on because the affected person may not be able to reproduce (or will be dead before he/she can reproduce). \n\nRecessive mutations can be carried without expressing a phenotype, so unless both alleles are mutated, no phenotype will be expressed.
948989
If there are two different alleles that cause different phenotypes, AND the phenotype of the het is indistinguishable from the phenotype of one of the homozygotes, then we say that that allele is completely dominant to the other, recessive allele.\n\nIncomplete dominance is usually used when the het has an intermediate phenotype due to haploinsufficiency, for instance, having one allele that codes for a working red pigment and one allele that codes for a broken pigment yields a pink flower that isn't making as much red pigment as the red homozygote.\n\nCo-dominance is when you can clearly see both gene products at the same time, like seeing blood cells with the A antigen and the B antigen.\n\n"Sickle-cell anemia illustrates that the terms dominance, incomplete dominance, and codominance are somewhat arbitrary. The type of dominance inferred depends on the phenotypic level at which the observations are being madeorganismal, cellular, or molecular. Indeed the same caution can be applied to many of the categories that scientists use to classify structures and processes; these categories are devised by humans for convenience of analysis."
220614
Well, in scientific form this is caused by the Mendelian trait, Law of Dominance. One trait (Btwn any of your parents)is more dominant than the other. It can also be caused by sex-linked traits found in the x-chromosome. There are characteristics that the daughter will get that is diff. from the son. It is just normal. I too look more like my dad.
1177562
you're asking this question because the darker-skin pigment genes *do* tend to be dominant or co-dominant. the answer may go back to your father's parentage ... were his recent ancestors all latino? recessive genes can skip generations before showing up.
449038
Dominance and recessive have nothing to do with frequency of an allele.  Basically, O is recessive because if you have an A allele and an O allele you will have type A blood, and if you have a B allele and an O allele you will have type B blood.  However, O is the most common type because most people don't have an A or a B allele, but just two O's.  The fact that A or B will be expressed if you have one doesn't make it more likely that you will have one.\n\nA and B are co-dominant (that's where the AB bloodtype comes from), but O is recessive to both A and B as it does not appear in the phenotype if an A or B allele is present.  Incidentally, these alleles are typically denoted I superscript A for A, I superscript B for B, and i for O, which reflects the dominance pattern as capital letters typically indicant dominant and lowercase indicate recessive.
863937
No. You are vaguely related to every one now. We are not getting closer. As mitochondrial mutation shows; the longer you are bifurcating from your common ancestor, the more you accumulate mutation and the more variety on that count alone. Not to mention somatic recombination, etc., etc..
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.
293753
Your friend is correct. I just studied this in school. Dark hair always dominates light hair. And the allele for green eyes overpowers the allele for blue eyes.
370115
1st part.... usually dominants are beneficial and more common in the population, but not always.  Huntington's disease which is fatal is dominant.  This has stayed in the population because it usually doesn't make the person sick until they are past child-bearing years.  Polydactyly (6 or more digits) is dominant as is syndactyly (fused digits).  Dwarfism is also dominant.\n2nd part...I don't see why not although I don't know of an example.
13809
Blood types are not evenly distributed throughout the human population. O+ is the most common, AB- is the rarest. There are also variations in blood-type distribution within human subpopulations. The figures given here are for people of European descent.\n\nType Frequency \nO+ 38% \nA+ 34% \nB+ 9% \nO- 7% \nA- 6% \nAB+ 3% \nB- 2% \nAB- 1%
388114
Perhaps you want a website that will take the pictures of both parents and somehow morph them?  The resulting photo will be more silly than a useful indication of what your offspring might look like.  Find a genetic planner and discuss the traits that you both possess, and you might figure out which traits are more likely to be dominant.  You can come up with educated guesses for hair and eye color, etc., but nothing more definitive than that.
899467
So handedness isn't a simple dominant-recessive trait.  It's actually linked to lateralisation - a process during development where the two halves of the brain each become specialised for particular tasks.  So all people who are right-handed are typically lateralised in the same way, for example they have an area of cortex on their left hemisphere dedicated to language (Broca's area) with parts of the right hemisphere dedicated to processing facial expressions (these are just two examples, there are many other left-right specialisations).  But left-handers and a small minority of right handers have different speciaisations.  So Broca's area may be found on the right hemisphere in these people.  Other features of the typical left-right patten may or may not be swapped producing several different patterns of lateralisation within the human population, one dominant pattern, seen in about 90% of people and several other patterns seen in just a few percent of people.\nWhich pattern of lateralisation an individual is, (including whether they are left-handed or right-handed) is determined by their genes.  Incidentally, a very small minority of people are naturally ambidextrous and don't actually have a genetically-determined hand preference.  However, experience and development also play a role.  So a genetically left-handed person who is made to use their right hand will, by virtue of practise become better at using their right-hand.  Similarly, people can teach themselves to be "ambidextrous" by practising with their non-preferred hand, but this isn't the same as natural ambidextrousness.\nSo to (finally!) answer your question about why you aren't left-handed, lateralisation patterns (which determine handedness) are influenced by many different genes and different combinations of these genes will produce different patterns, so while left-handedness will "run in the family" it can't be predicted as easily or reliably as hair colour, or eye colour or any other single gene trait.
234596
Everyone who reproduces passes his/her genes on to future generations.  If you assume a population's birth and death rates are independent of light/dark skin genes then this means that whatever ratio is currently in place will stay that way.  (Also assume the population is isolated: no large fluxes of different ratios of phenotypes are coming in or leaving.)\n\nIf you ignore death rates, then populations grow exponentially.  This is characterized by a doubling time.  Say the doubling time is like 20 years (made up number) and your population of 100 individuals is 75 dark and 25 light.  If you wait 20 years then there will be 200 individuals: 150 dark skinned people and 50 light skinned people.  The ratios are still 75% and 25%.  The ratios will be constant whether or not different phenotypes reproduce with each other, too.  However, gene expression (dominant, recessive) could make the ratios look different on the outside (favoring the appearance of the dominant phenotype), but the actual gene ratios would still be constant.
898195
the result of fl is barr(if it is dominant) or else white.one main ground rule of inheritance is that it may be white or barr but one can be dominant only for 2 generations it's not the matter but in  the third gen.the recessive will take the turn
707484
A)\n\nThe white mouse shares the phenotype and genotype of parents\n\nMother white mouse: aa\nFather white mouse: aa\nWhite mouse: aa\n\nThe Brown mouse might be 2 things, \neither heterozygous: Aa\nor homozygous dominant: AA\n\n(in these type of exercises, when you mate something with an animal from which you have no info, he's usually homozygous. And if he wasn't the next step would not work.)\n\nTherefore, the mating of the white mouse (aa) with the brown mouse (AA) give only heterozygous (Aa) brown mice.\n\nWhy not B?\nBecause if the white mouse was heterozygous (Bb), that meant that "White" was the dominant gene, and the brown mouse had to be homozygous recessive (bb). But now you can say that they still could have a brown mice offspring, because they both carry a recessive allele (bb). Well, yes, but eventually white mice would appear in the be born (BB, Bb). This way it would never be all brown.\n\nWhy not C?\nBecause all the offspring would then be all white and never brown. It's the inverse of example A).\n\nWhy not D?\nBecause the white mouse is alive and fertile.