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What is the probability that a recessive trait will appear?
It depends on the genotype of the parents, but assuming there is an equal chance of being dominant homozygous, recessive homozygous or heterozgous and there are only two possible genes, there is a 1 in 4 chance that the recessive trait will appear.
What is the probability that offspring of a cross between a homozygous recessive parent and a hetezyguous parent will be homozygous recessive?
In a cross between a homozygous recessive parent (AA) and a heterozygous parent (Aa), the possible genotypes of the offspring are 50% homozygous recessive (AA) and 50% heterozygous (Aa). Therefore, the probability that an offspring will be homozygous recessive is 50%.
Where did the ratio 9331 come from include what each of these four numbers mean?
The 9/3/3/1 ration is the ratio of phenotypes that are the result of a dihybrid cross. Consider two genes, A and B, that reside on different chromosomes (so that they independently assort). Assume each gene has two alleles. For A, A is dominant and a is recessive, while for the B gene, B is dominant and b is recessive. Now consider a cross between two individuals that are heterozygous for both genes (this is called a dihybrid cross): AaBb X AaBb There are only 4 possible gametes that each individual can produce (in equal proportion): AB Ab aB ab So if we cross the two we get 16 combinations. This will result in 9 possible genotypes: AABB AABb AAbb AaBB AaBb Aabb aaBB aaBb aabb However, there are only 4 possible phenotypes (with proportion in parentheses): Dominant A and B (9/16) (AABB, AABb, AaBB, AaBb) Dominant A, Recessive B (3/16) (AAbb, Aabb) Recessive A, Dominant B (3/16) (aaBB, aaBb) Recessive A, Recessive B (1/16) (aabb)
A homozygous dominant black bear is mated with a recessive brown bear what phenotype will probably result in the offspring of the two bears?
Phenotype: Black Bear x Brown Bear Genotype: BB x bb Possible gametes: B B b b Possible B B crosses: b Bb Bb b Bb Bb Phenotype of offspring: Only Black bears
Is it possible to not have a cliterix?
Yes, it is possible for some individuals to be born without a clitoris due to congenital conditions, such as androgen insensitivity syndrome or differences in sexual development. Additionally, surgical removal or injury can also result in the absence of a clitoris. However, most individuals assigned female at birth typically have a clitoris.
What are the three different combinations of alleles?
If the gene for a trait has two alleles, one dominant (D) and one recessive (d) there are three possible combinations in the genotype: DD (homozygous dominant) Dd (heterozygous) dd (homozygous recessive)
What gene is masked if it is paired with a dominant gene?
The different forms of a gene are called alleles. In Mendelian genetics, a gene has a dominant allele and a recessive allele. The dominant allele masks the recessive allele if present. So there are two possible dominant genotypes: homozygous dominant, in which both dominant alleles are present; and heterozygous, in which one allele is dominant and the other allele is recessive. The only way to express a recessive trait is to have the homozygous recessive genotype.
What is the probability that a recessive trait will appear?
It depends on the genotype of the parents, but assuming there is an equal chance of being dominant homozygous, recessive homozygous or heterozgous and there are only two possible genes, there is a 1 in 4 chance that the recessive trait will appear.
What is a genotype and 3 possible genotypes?
Homozygous dominant (Ex:AA) Heterozygous (Ex:Aa) Homozygous recessive (Ex:aa)
When an individual have two identical alleles for the same trait it is called?
Having two similar alleles for a trait is called being homozygous. It is possible to be homozygous for a dominant or recessive trait.
What are the different forms of a gene either dominant or recessive?
Genes can exist in different forms called alleles. Dominant alleles are expressed when present, masking the effects of recessive alleles. Recessive alleles are only expressed when two copies are present, one from each parent. This results in a wide range of possible genetic combinations and expressions.
How did Mendel know the the tall pea plants in the first generation had a hidden factor for shortness?
By "test cross" you can know whether it homozygous dominant or heterozygous dominant...in homozygous both alleles code for the dominant trait, in heterozygous one allele is recessive (what you called a "hidden factor"). To perform the test cross, cross a homozygous recessive with the first generation. Lets suppose tall pea tree in the first generation is hetrozygous dominant (Xx) and has alleles X (dominant) and x (recessive). When we cross it with homozygous recessive (xx) X x x :Xx xx x :Xx xx we get half offspring showing dominant trait (Xx) and half showing recessive (xx). If the first generation was homozygous (which is not possible) the result would be X X x: Xx Xx x: Xx Xx all the offspring showing dominant trait and it doesn't really happen when we cross the first generation with homozygous recessive. It means that the genotype of first generation is heterozygous (has a hidden factor or a recessive allele x). Note:You must know what the recessive and dominant allele means...In presence of a dominant allele, recessice character is not expressed but it is present is heterozygous. If both alleles are recessive (homozygous recessive) then the recessive trait is expressed. If both the alleles are dominant (homozygous dominant) obviusly the dominant trait is showed by the individual.
What is phenotype of Rr?
It is Dominant. R is the dominant and r is the recessive. The dominate trait shadows the recessive trait. It is Dominant. R is the dominant and r is the recessive. The dominate trait shadows the recessive trait. Is dominant. dominant can be RR or Rr. but when its recessive its rr.
What is an example of two heterozygous parents?
The possible genotypes of parents who are heterozygous would be found using a punnet square. The outcome would be 50 percent heterozygous dominant, 25 percent homozygous dominant, and 25 percent homozygous recessive.
Predict what genotype the children will have if one parent is homozygous recessive for earlobes and homozygous dominant for hairline (eeWW) and the other parent is homozygous dominant for unattached earlobes and homozygous recessive for hairline (EEww )?
The only possible outcome is EeWw, which will express the dominant genes but carry the recessive ones. They get one chromosome from each parent, but since the parents all have matching chromsomes in this case then it doesn't matter which one they get. Since one parent has EE, E is the only one that can be passed on. Since the other has ee, they can only pass on e. Therefore, the child can only possible have Ee, as they get one from each parent.
What are the possible offspring outcome if parent one Tt crosses with parent to tt?
A heterozygous cross.Tt X TtOne homozygous dominant--TTTwo heterozygous dominant---TtOne homozygous recessive--ttAll on a statistical average outcome.
How do geneticists normally tell whether an organism exhibiting a dominant phenotype is homozygous or heterozygous?
They perform a test cross. A test cross takes the unknown genotype and crosses it with a known homozygous recessive. If the F1 generation is all dominant, then they know the organism was a homozygous recessive. If recessive offspring appear, then the organism was a heterozygote. As an example, consider a gene with two alleles, A and a, with Adominant. Now consider the test cross. The unknown genotype can only be one of two possibilities: AA (homozgous dominant) Aa (heterozygous) In a test cross,the unknown genotype is crossed with a known homozygous recessive. Since there are only two possible unknown genotypes, there can be only two possible results. First, consider the case of the unknown genotype being a homozygous dominant. The cross looks like this: AA X aa Remember that a homozygote for an allele can only produce one kind of gamete. In this case the homozygous dominant can only produce gametes with the allele A in them, while the homozygous recessive can only produce gametes with the recessive allele a in them. This means the F1 offspring can only be ONE genotype; Aa. Therefore, all of the offspring would have the dominant phenotype. Now consider the other possible cross, where the unknown genotype is heterozygous: AaX aa Remember that a heterozygote can produce two types of gametes. In this case, the unknown would produce gametes with the dominant allele A or the recessive allele a. The homozygous recessive would still only produce one kind gamete, with the recessive a allele. Therefore, we expect to see only two genotypes in the F1, Aa and aa, in equal proportions. In either case, only one test cross is needed to tell one immediately the nature of the unknown genotype. If all of the F1 are of the dominant phenotype, then the unknown genotype must be homozygous dominant; if a mixture of phenotypes appears in equal proportion, then the unknown genotype must be a heterozygote.
