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Depends on the characteristic. Assuming you're talking about a very simple monogenic characteristic (ie. a characteristic which is dependent on one gene only) your dominant allele will always trump your recessive allele. So, one copy of your dominant allele is all that's needed to give you that characteristic (final genotype is either homozygous dominant or heterozygous), whereas you'd need two copies of your recessive allele (homozygous recessive) to get that characteristic. Much beyond that and it gets verycomplicated.
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∙ 14y ago
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∙ 11y agodouble dose or one from each parent
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Why do recessive trail are more common in some cases?
They're not necessarily, but they can be. When a recessive trait is more common, it likely because it was advantageous to have that trait so the species evolved to have more of it in the gene pool. Also, since dominant traits are expressed over recessive traits, natural selection has more of an effect on them.
Is it true that all genes show simple patterns of dominant and recessive allleles?
No, it is not true that all genes show simple patterns of dominant and recessive alleles. When Mendel did his studies on peas, he was lucky in that the genes he worked with showed those patterns. Many genes are much more complex and often involve more than one gene. Many genes show intermediate expressions between dominant and recessive.
When a trait has more than two alleles, how is that trait inherited?
Not sure if I understand the question correctly... but any single set of normal allelic pairs would be inherited according to standard Mendelian ratios, but the phenotypic expression would be more complex and would not reflect Mendelian ratios there might be an additive effect of having alleles A, B C as opposed to the recessive complement a, b, c - this would pertain to traits as drosophila wing span, all three dominant alleles result in larger wingspan but this is often complicated by the presence of alleles which can "knock out" the effect of entire complements of alleles, effectively cancelling out expression no matter how many other pro-length alleles are present... it is difficult to talk about in the abstract... :)
What the different between a dominant and recessive trait?
In simple Mendelian genetics, there may be several alleles (variations) for a given trait. since organisms generally have two pairs of chromosomes, they have two alleles. A dominant allele is one that when it is present, always shows itself. A recessive allele only shows when there are two copies of the recessive allele. For example, suppose brown hair is dominant and black hair is recessive. If there are any copies of the brown hair allele, the person's hair will be brown. A person's hair will be black only if they have two copies of the black hair allele. In reality, genetics is much more complicated than simply dominant and recessive as many genes may influence one trait.
Does a dominant allele mask a ressessive allele?
In diploid organisms (those with two copies of each gene carried on separate chromosomes), one of the copies of a given gene may differ from the other copy of the same gene on the twin chromosome. In some cases one version of the gene (the dominant allele) has the effect of 'masking' the activity of the other (the recessive allele); that is, the presence of the dominant allele negates the effect of the recessive allele on the organism's phenotype. There are many mechanisms which can cause this phenomena, and it depends on the particular genes involved, but a simple model is one where the recessive allele is a biochemically inactive version of the dominant allele. In this case the dominant allele would mask the effect of the recessive allele by providing an active version of the gene. The dominant phenotype would be the one which shows the downstream effects of this activity, and the recessive phenotype one which shows the downstream effects of a lack of activity. The dominant allele is said to 'mask' the recessive allele because only one copy is required to result in an elimination of the recessive phenotype, whereas all copies of the gene must be the recessive allele to result in the recessive phenotype.
How many recessive alleles are needed to show up in the phenotype?
Two (together).
Why are many harmful alleles recessive?
The reason many harmful alleles are recessive is because the harmful alleles that were dominant stopped the carrier from reproducing so the allele was not carried on. A dominant trait is expressed if present and would harm the carrier. A recessive trait however can remain in the genotype of an individual and not the phenotype so they will not be harmed by the trait but can pass it on to offspring. In short: dominant harmful alleles stopped the carriers from producing so the allele was not spread.
Why some chromosomes are recessive and the others are domainent?
Actually a chromosome consists of many genes/alleles and is neither recessive or dominant in and of itself.
What is two dominant alleles called?
In eyes, it would be brown is dominant, and blue is recessive. Free earlobe allele is said to be dominant over the attached earlobe allele. When an organism has two dominant alleles for a trait, it is called homozygous dominant. Two recessive alleles for a trait is homozygous recessive.
How many alleles are usually in the gene pool for each trait?
Each gene has a dominate and recessive allele, so there are two types of alleles in each gene. The dominate allele is stronger than the recessive allele unless there are two recessive alleles.
How many recessive alleles must a person have to have albinism?
2
Albinism is a recessive trait in humans that is controlled by a single gene how many recessive alleles must a person have to have albinism?
2
Having to bent thumb is a recessive trait in humans the trait is controlled by a single gene how many recessive alleles must a person have to have a bent thumb?
2
Whether an allele is dominant or recessive depends on?
its random really, some genes are recessive, and some are dominant if a gene is dominant than it will be expressed if it is present the only way for a recessive gene to be expressed is if there are two alleles for that traitIt's not random at all. There can be many reasons. One classic reason is given here. First, know that most genes encode proteins. A dominant gene (really, an allele) may encode for a functional protein while a recessive gene may encode for a non-functional proteindominant genes contain genes that are strong and recessive genes contain genes that are weak.
How many alleles for hemophilia do females have?
females have 2 alleles for hemophilia, (X^hX^H) and (X^hX^h) if H is the normal allele and h is the recessive allele for hemophilia
When trait is called recessive?
recessive is when you have another allele that supress the recessive one, you have to thing how this could be done in a methabolic pathway, and you will see that exist many ways for an allele be dominant and the other recessive (you just can say dominant and recessive if you are talking at alleles ,this is genes at the same locus. my mother language is no inglish maybe i have comit many gramatical errors but what i am saying is correc i am student of biotechnology.
What keeps alleles in populations?
well it depends on how many many of them. my opinion is that they stay in population because height is controlled by a recessive allele your welcome dumb-asses =)
