What is it called when two genes are in a cell and one gene's phenotype is expressed and one is not?
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.
576339
Defination of epistasis - A double mutant where one mutation masks the phenotype of another mutation.\n\nNote that epistasis is not the same thing as dominance. With epistasis a mutation in one gene masks the expression of a different gene. With dominance, one allele of a gene masks the expression of another allele of the same gene.\n\nFor instance, a mutant gene that causes complete baldness would be epistatic to a mutant gene that determines hair color. Likewise, a mutation preventing an early step in a biochemical pathway will be epistatic to a mutation that prevents a step later in the same pathway (that is, an "upstream" mutant phenotype will obscure a "downstream" mutant phenotype). Two examples of how tests of epistasis can be used to analyze biochemical reactions are shown below. \n\n\n\n--------------------------------------------------------------------------------\n\nQUESTION: Two mutations were isolated with different effects on proline utilization: the mutation put-1020 makes cells constitutively express the putP gene at high levels, while the mutation put-1222 prevents expression of the putP gene. To determine if these two mutations affect different "regulatory pathways" or if they both affect the same "regulatory pathway", the double mutant was constructed. The phenotype of the put-1020 put-1222 double mutant is constitutive expression of the putP gene. Suggest a simple explanation for these results. What results would you expect if the two mutations affected different pathways? \n\nANSWER: The put-1020 is epistatic to put-1222. The simplest explanation of these results is that both the put-1020 mutation and the put-1222 mutation affect the same regulatory pathway. If the two mutations affected independent regulatory pathways then the phenotype of the double mutant would probably be intermediate between the two extremes observed in the single mutants. \ncontinues here:\nhttp://www.sci.sdsu.edu/~smaloy/MicrobialGenetics/topics/genetic-analysis/epistasis.html
1065164
The cells from two separate eggs (twins) can combine into one whilst in the mother's womb - thus one child is born but has two dna's instead of one
564737
A gene is part of a DNA molecule, particularly, the part of that DNA molecule required to make a gene product.  For instance, there is one gene that codes for the protein that determines ABO blood type.  You have two copies of that gene (they might be identical, or they might not be, depending on the gene), one from each parent.  For many genes, there exist different "versions" in a population, for instance, for the ABO blood type gene, there are three "version", or alleles of the gene, and we call them A,B and O.\n\nA genotype is a simple description of which alleles you have for a certain gene, or it might be a description of your alleles for a number of genes.  So, if you have the A allele of the ABO gene, and the B allele, your genotype is AB.\n\nMany diseases are caused by differences in a single gene, such as sickle-cell anemia.  People with one or two copies of a certain beta hemoglobin will suffer the affects of sickle-cell disease.  People with one copy of the disease-causing gene, and one copy of the “normal” gene will not have the full effects of sickle-cell, but they do have a non-normal phenotype.\n\nSome genetic diseases only manifest when a person has two copies of the disease causing alleles (we’d say that those alleles are recessive to the wild-type allele), some genetic diseases can be caused by having only a single copy of the allele (because the disease causing gene is totally dominant to the wild-type allele).  Some genetic diseases are incompletely penetrant; that is, some times, people who have two disease causing alleles won’t have the disease phenotype; either because of how the environment interacts with the gene, or because of other alleles in other genes interacting with the product of the disease gene, preventing the disease from manifesting.\n\nSome of the other answers on this board are making very broad statements about dominant “genes” (there’s really no such thing, there are only alleles which can be dominant to other alleles), or saying that diseases are only cause by carrying two recessive alleles (not true, some genetic diseases are caused by classically dominant alleles).  While a high-schooler might only learn about examples of genes that behave according to classical Mendelian rules, reality is a great deal more complex.  Diseases can be caused by classically recessive alleles, classically dominant alleles, alleles which are co-dominant to other alleles, alleles whose phenotpye is influenced by epigentic interactions with other genes...etc.
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Its called a "Chimera"\n\nIn response to the response below about tetraploidy.  Tetraploidy is highly lethal.  The person asking the question is referring to a tv show where there are people who have "two sets of chromosomes."  Not two identical sets in the same cell that didn't undergo mitosis correctly (and maybe meiosis).  The question is asking about people who have their "twin inside of them."  A condition where a fraternal twin egg is ingulfed by the other egg resulting in a chimera.  Check the references:
993777
Those terms are for individual genes, not people. A gene is made up of a pair of alleles, one from each gamete. These alleles can be one of many variations. If the alleles are identical, the gene is homozygous.
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phenotype... ;p\n\nthe phenotype of an individual organism is either its total physical appearance and constitution or a specific manifestation of a trait, such as size, eye color, or behavior that varies between individuals. phenotype is determined to some extent by genotype, or by the identity of the alleles that an individual carries at one or more positions on the chromosomes. many phenotypes are determined by multiple genes and influenced by environmental factors.
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1. In eukaryotes the expressed part of genes are called exons and the pieces that are removed before transcription are called introns.\n2. If there is a mutation in one stop codon the other will most likely still be functional so you will usually get a functional product in the end.
593627
They are different varieties due to different in DNA color sequence.This is regulated by gene regulation and expression by making novel proteins.
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Oncogenes are mutated genes that contribute to cancer development by disrupting a cell’s ability to control its own growth and DNA repair mechanisms2,5. Normally mitosis (cell division) is a carefully regulated event, requiring the activation of one protein to activate another, in what is known as a signal transduction cascade. This cascade eventually culminates in changes in gene expression that prepares the cell for mitotic events.\n\nOncogenes are mutated forms of proto-oncogenes; these genes are often involved in growth signalling and anti-apoptotic pathways. When proto-oncogenes mutate to become oncogenes they retain their functionality, but are no longer capable of responding to normal regulatory signals (see Figure 1).
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The genotype is the specific genetic makeup (the specific genome) of an individual, in the form of DNA. Together with the environmental variation that influences the individual, it codes for the phenotype of that individual. Non-hereditary mutations are not classically understood as representing the individuals' genotype. Hence, scientists and doctors sometimes talk for example about the (geno)type of a particular cancer, thus separating the disease from the diseased. While codons for different amino acids may change in a random mutation (changing the sequence coding a gene), this doesn't necessarily alter the phenotype.\n\nTypically, one refers to an individual's genotype with regard to a particular gene of interest and, in polyploid individuals, it refers to what combination of alleles the individual carries (see homozygous, heterozygous). Any given gene will usually cause an observable change in an organism, known as the phenotype. The terms genotype and phenotype are distinct for at least two reasons:\n1. To distinguish the source of an observer's knowledge (one can know about genotype by observing DNA; one can know about phenotype by observing outward appearance of an organism). \n2. Genotype and phenotype are not always directly correlated. Some genes only express a given phenotype in certain environmental conditions. Conversely, some phenotypes could be the result of multiple genotypes. The genotype is commonly mixed up with the Phenotype which refers to the physical appearance\n\nThe distinction between genotype and phenotype is commonly experienced when studying family patterns for certain hereditary diseases or conditions, for example, hemophilia. Sometimes people who do not have hemophilia can have children with the disease, because the parents each "carried" hemophilia genes in their body, even though these genes have no effect on the parents health. The parents in this case are called carriers. Healthy people who are not carriers and healthy people who are carriers of the hemophilia gene have the same outer appearance (ie they do not have the disease), therefore they are said to have the same phenotype. However, the carriers have the gene and the other healthy people do not (they have different genotypes).\n\nWith careful experimental design, one can use statistical methods to correlate differences in the genotypes of populations with differences in their observed phenotype. These association studies can be used to determine the genetic risk factors associated with a disease. They may even be able to differentiate between populations who may or may not respond favorably to a particular drug treatment. Such an approach is known as personalized medicine.\n\nInspired by the biological concept and usefulness of genotypes, computer science employs simulated genotypes in genetic programming and evolutionary algorithms. Such techniques can help evolve mathematical solutions to certain types of otherwise difficult problems.
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This is when a cell reproduces by either mitosis (in most cases) or meiosis (in the case of sex cells)\n\nSee http://www.scienceaid.co.uk/celldivision.html for more information
117313
chimera - thats what people are called when they have 2 sets of DNA.  This occurs when one twin attempts to absorb the other in utero.\nthis will result in 2 sets of DNA.  Such as your hair may carry one set of DNA and your liver another.  I have seen this on TLC.  It showed a woman who was facing custody battles because her paternity tests were showing that her children werent hers - but they were, the DNA from the samples they took were not the DNA she passed down to her children.
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There are many definitions for the word gene. Basically it is a unit of heredity. To many biologists that means a group of DNA molecules that code for one particular protein. \n\nThey are found in MOST of the cells in your body.\n\nThere are those genes in chromosomes in the nucleus of all cells that have nuclei (i.e. not red blood cells).\n\nThere are also genes in other bits of the cell e.g. the mitochondria (which is the place where energy is generated). These genes are completely seperate from the ones in the nucleus.\n\nPlants have yet more genes in their chloroplasts (where photosynthesis happens).\n\nViruses have genes too, but they may be made of RNA instead of DNA.
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Phenotypes: AB+ or AB-\n\nAntigens: A and B\n\nGenotypes: AB (+ or -)\n\nThanks micro_girl.  I should have made that more clear.  A and B are separate proteins, and when they are both present the resulting phenotype is AB.  Sorry if my original answer was misleading.  I fixed it.
846506
the way you have it is good chromozones are part of genes wich are part of cells
135811
gene I think is what you are looking for. Not sure the question makes sence.