How many dominant alleles are required in a genotype to show the dominant phenotype?

Answer 1

If the allele is dominant, you only need one copy for it to be expressed in the phenotype (you have TWO alleles for each trait) If the allele is dominant, you only need one copy for it to be expressed in the phenotype (you have TWO alleles for each trait)

Answer 2

Only one because if you put a dominant allele with a recessive allele the dominant allele will always show up no matter what. For example if you breed a Male Homozygous black lab with a Female Homozygous blond lab the black will show up in all of the dogs, because the male only has the dominant trait and passes it on to all of the pups.

Answer 3

every thing has two allele traits, if you are dominant or recessive for a trait is determined by your alleles. there are two types of alleles, dominant and recessive. The trait in an organism is determined by the organism's parents. To find whether the organism, in this case a person, has a dominant or recessive trait you can use a punnent square. In science, a dominant trait is indicated by a capital letter (A) and a recessive trait is a lowercase letter (a).

Now, if one parent is homozygous, the two traits the parent has is the same, thus the prefix, homo. homozygous dominant (A,A) homozygous recessive (a,a). But that parent can be heterozygous, or having a dominant and recessive trait (A,a) a dominant trait will ALWAYS over shadow a recessive trait, so if you have one dominant allele, you are dominant for that trait. Now using a punnent square:

Parent one: Homozygous recessive (a,a)

Parent two: Heterozygous (A,a)

punnent square

a a

A A,a A,a

a a,a a,a

the chance of the offspring being dominant for this trait is 50% and the chance of the offspring having a recessive trait 50%

thus you only need one dominant allele for this trait to be expresses

Answer 4

one, but usually there is a reccesive gene too, but the dominant is still taking control. Lets say you have a dominant R for red hair, and a recesive r for othes. You will still have red hair because that dominant took over and now your gene is Rr.

Answer 5

Only one dominant allele is required in a genotype to show the dominant phenotype. Dominant alleles mask the effects of recessive alleles in heterozygous individuals.

Answer 6

4

Answer 7

One.