No, homozygous recessive indivuals MUST have two of the reccessive gene (bb), the possible combinations are bb,bb,bb,bb thus only a recessive trait is possible
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.
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%.
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)
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
Yes, it is possible for two tongue-rolling parents to have a non-tongue-rolling baby. Tongue rolling is often considered a genetic trait, typically associated with a dominant allele. However, if both parents carry a recessive allele for non-tongue rolling, there is a chance they could pass that trait to their child, resulting in a non-tongue-rolling offspring.
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)
For a plant with green seeds, the possible genotypes depend on whether green seed color is dominant or recessive. If green is dominant (G), the genotypes could be homozygous dominant (GG) or heterozygous (Gg). If green is recessive (g), the only genotype would be homozygous recessive (gg). Therefore, the possible genotypes for green seeds are GG or Gg, assuming green is dominant.
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.
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.
Homozygous dominant (Ex:AA) Heterozygous (Ex:Aa) Homozygous recessive (Ex:aa)
Having two similar alleles for a trait is called being homozygous. It is possible to be homozygous for a dominant or recessive trait.
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.
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.
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.
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.
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.
A heterozygous cross.Tt X TtOne homozygous dominant--TTTwo heterozygous dominant---TtOne homozygous recessive--ttAll on a statistical average outcome.