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How can two parents with dominant allele have a child with recessive allele?
Wiki User
∙ 10y ago
Even though the parents may both have dominant it is a random selection. Also somewhere down the family line there is probably a recessive. *Both parents have a dominant and recessive phenotype (Bb), so there's a 25% chance of having a child with recessive phenotypes (bb).
Wiki User
∙ 14y ago
Wiki User
∙ 15y agoLet us assume that a healthy phenotype results from either the HH or Hh genotypes and a diseased phenotype results from the hh genotype. Therefore, if both parents are heterozygotes (Hh), then the possible genotypes for their offspring are HH, Hh, and hh (Draw a Punnett Square to make sure) in a ration of 1:2:1. This means that there is always a 1 in 4 chance that a child produced by two heterozygote parents is going to be of the diseased phenotype.
Wiki User
∙ 12y agoSome people who have the allele for a disease that do not pass on the genefor it is because they only received the gene from one parent. In order to be born with the disease both parents would have to be carriers.
Wiki User
∙ 14y agoMany genetic disorders are caused by recessive alleles, but not all of them. Recessive genes do not harm the carrier as long as there is an working version of the allele on the second chromosome present. So they are passed along from generation to generation until they meet a second ill working copy. This will result in disease or other damage on the individual with those two recessive genes. So within a population those recessive can go unnoticed for long times.
If a dominant or additive acting gene causes problems the negative effects are obvious in all individuals carrying that gene. And individuals of lower fitness will most likely leave smaller numbers of offspring. So nature does more weeding out on those genes. But this will not work on recessive genes as long as there is a properly working allele present. So recessive genes tend to stay for ever, although on low levels.
Wiki User
∙ 10y agoThe parents both must have the recessive allele, and the child must have recieved only the recessive allele, not the dominant one. If the parents each have dominant gene "G" and recessive gene "g," (so each has Gg and expresses the G) then there are three possibilites for the child: 1. it has GG (25% chance) 2. it has Gg (50% chance) or 3. it has gg (25% chance). The final possibility shows how the child would exhibit a recessive allele even if his/her parents express the dominante allele.
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What is difference between a dominant trait and a recessive trait?
A recessive trait is a trait that is not shown or expressed physically but is retained within the persons genes, whereas a dominant trait is a trait which opresses the recessive trait and is prodominantly shown or expressed physically. For example it is possible for two red-haired parents, both with recessive dark haired genes, to have a dark haired child. they must both have the recessive gene or the dominant gene of red - hair will be expressed in the child
In order for a child to inherit a recessive trait both parents must be carriers of the recessive gene?
No. A recessive gene can be inherited from one parent, a dominant from another, or two alike dominants. (No such thing as two alike recessive, the gene with the furthest back dominant gene. Say a blonde little girl has a blonde hybrid mother and a brown hybrid father. She ended up getting brown recessive. Since both of her parents were hybrid, she only had a recessive hair color gene from one parent.
What are the difference between dominant and recessive genes?
Dominant genes will cover up recessive genes. Take a simplified version of eye color for example. Brown is dominant and blue is recessive. Someone might have the allele for both brown and blue, but their eyes will be brown because of the dominent brown gene. If there are two parents that carry the recessive gene, neither will be blue eyed, but they will have a chance of having a blue eyed child if both pass on the recessive gene.
What is the genotype of a child if the mother is homozygous for the dominant trait and the father is homozygous for the recessive trait?
The dominant parent is most likely homozygous dominant, and the recessive parent has only the homozygous genotype. So the dominant parent can pass on only dominant alleles for this trait, and the recessive parent can pass on only recessive alleles for this trait. So all of the offspring would be heterozygous and have the dominant phenotype.
A widow's peak is a V-shaped area of the hairline in the center of the forehead The allele for having a widow's peak is dominant to the allele for not having a widow's peak If two parents do not hav?
None. Since it is dominant, both would have to show it to pass in on. If both show it and both have the recessive (straight), the child would have a 3:1 chance of showing it.
Will Two blue eyed parents recessive definitely have a blue eyed Child?
yes because two parents with recessive traits do not have the dominant allele to pass onto the child
What is difference between a dominant trait and a recessive trait?
A recessive trait is a trait that is not shown or expressed physically but is retained within the persons genes, whereas a dominant trait is a trait which opresses the recessive trait and is prodominantly shown or expressed physically. For example it is possible for two red-haired parents, both with recessive dark haired genes, to have a dark haired child. they must both have the recessive gene or the dominant gene of red - hair will be expressed in the child
If both parents O positive can child be A positive?
If both parents are O+ve, it means they have i allele, which is a recessive allele. For a person to have A+ve blood group, IA allele should be present. But in case of both parents being O+ve, there is no possibility that either of the parents carry the IA allele since it is a dominant allele. Thus the child would have to be O+ve.
How is Dominant and Recessive differ?
A child inherits a quality if one its parents has the dominant gene for it.With a recessive characteristic, both parents have to have it.
If straight hair is genetic why do you have straight if none f your ancestors did?
it is because the parents each were heterozyous dominant. meaning each of them had a dominant allele and a recessive allele. the dominant allele would be the curly hair, and the recessive allele would be the straight hair. There would be a 1/4 chance that the child would have curly hair, and a 3/4 chance that they would have curly hair. Say that the Curly hair allele was H and the straight hair allele was h. In order for the parents to have curly hair, they would either have to have an HH gamete or an Hh gamete. Seeing as though the child came out with curley hair, both parents would have to have an Hh gamete. In order to find out the probability, you multiply the parents gametes. (Hh)(Hh). This will give you HH, Hh, Hh, hh. seeing has three of the gametes have the dominant allele, this child will have curly hair, and one is a homozygous recessive, so it will turn out with straight hair.
What is the probability that each child born to two carriers of a recessive disorder allele will have the disorder?
The child will have the disorder, only if the recessive allele from both the parents is transferred to the child. Therefore, the probability is 1/4.
Is it true that people who are heterozygous recessive allele but who have a normal phenotype eill not pass the harmful recessive allele to their kids?
It depends on the genotype of the childs other parent. If your partner is heterozygous as well then there is a 25% chance your child will be homozygous recessive. If they are homozygous dominant then none of your children will have the phenotype of the recessive trait. They will just possibly be carriers of the recessive allele.
If both parents are a positive can the child be a negative?
yes. because of recessive genes. recesive genes are traits that will not be shown if the dominant gene for that trait is present. every person has at least two alleles(forms of traits) for each trait that is shown. One you see and the other you may not. For example, two parents may have brown eyes, but if they have a child that has blue eyes then you know that the parents must have carried the recessive gene. this is possible because the brown eye allele is dominant and the blue eye allele is recessive. Even though you did not see the blue eye trait in either of the parents it was still present.
In order for a child to inherit a recessive trait both parents must be carriers of the recessive gene?
No. A recessive gene can be inherited from one parent, a dominant from another, or two alike dominants. (No such thing as two alike recessive, the gene with the furthest back dominant gene. Say a blonde little girl has a blonde hybrid mother and a brown hybrid father. She ended up getting brown recessive. Since both of her parents were hybrid, she only had a recessive hair color gene from one parent.
What are the difference between dominant and recessive genes?
Dominant genes will cover up recessive genes. Take a simplified version of eye color for example. Brown is dominant and blue is recessive. Someone might have the allele for both brown and blue, but their eyes will be brown because of the dominent brown gene. If there are two parents that carry the recessive gene, neither will be blue eyed, but they will have a chance of having a blue eyed child if both pass on the recessive gene.
Difference between dominant and recessive genes?
dominant genes are more likely to be passed down to a child than recessive genes. Here's an example: A woman has black hair and blue eyes. Her husband has blonde hair and brown eyes. Their child will most likely have brown eyes and black hair, because black hair and brown eyes are dominant genes, while blonde hair and blue eyes are recessive. It is, of course, still possible for the child to be blonde and blue-eyed, only less likely. However, if the father had blue eyes too, it would be most likely that the child would have blue eyes. Grandparents are also a factor: say that both parents have blue eyes, but one or more of the child's grandparents (or anyone down the genetic line, actually) has brown eyes. It is therefore also possible for the child to have brown eyes. hope it helped
If a child has blonde hair and both the parents have brown hair what does that tell you about the allele for blonde hair?
It tells you that even though the parents have brown hair, they have a recessive allele for blonde hair also. And even though brown is suppose to be visually dominant, it is not the case at all. Two brown heads can make a blonde or brown, and of course even red haired child. Another way to look at it may be the parents have the following alleles for hair color: (b,b) - (b,b) in which case the dominant allele is Blonde or Brown.
