Which two combinations of alleles could produce a trait controlled by a dominant allele?
Which two combinations of alleles could produce a trait controlled by a dominant allele? A trait controlled by a dominant allele will be produced if there are two dominant alleles present (homozygous dominant) or one dominant allele and one recessive allele (heterozygous).
What characteristics are controlled by a single gene?
Some characteristics are controlled by a single gene, such as fur in animals and red-green colour blindness in humans. Each gene might have different forms, and these are called alleles. The diagram shows the relationship between the cell, its nucleus, chromosomes in the nucleus, and genes.
Why does an individual always have only two alleles for a given gene?
Since diploid organisms have two copies of each chromosome, they have two of each gene. Since genes come in more than one version, an organism can have two of the same alleles of a gene, or two different alleles. This is important because alleles can be dominant, recessive, or codominant to each other.
Which term indicates that a single gene has two or more alleles present in a population?
A particular genotype is described as homozygous if it features two identical alleles and as heterozygous if the two alleles differ.
What combination of alleles will produce a recessive trait?
Only individuals with an aa genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait. One example of a recessive inherited trait is a smooth chin, as opposed to a dominant cleft chin.
Which trait is controlled by a dominant allele *?
The dominant allele (E) results in the phenotype of free earlobes. The recessive allele (e) is for attached earlobes. Widow’s peak occurs when the hairline forms a distinct point in the center of the forehead. Widow’s peak is controlled by a dominant allele (W).
What are 2 single allele traits?
Some traits, like hair color, come from many different genes, but other traits are controlled by a single gene. Those simple traits include Huntington’s disease, galactosemia and phenylketonuria.
Can a single gene control a single trait?
A pleiotropic gene is a single gene that controls more than one trait. … Pleiotropy should not be confused with polygenic traits, in which multiple genes converge to result in a single phenotype.
Can there be more than two alleles present for any given gene?
Although individual humans (and all diploid organisms) can only have two alleles for a given gene, multiple alleles may exist in a population level, and different individuals in the population may have different pairs of these alleles.
What are all the alleles of a gene or genes present in a given individual?
An individual’s genotype for that gene is the set of alleles it happens to possess. In a diploid organism, one that has two copies of each chromosome, two alleles make up the individual’s genotype.
How many alleles does one have for each gene?
An individual inherits two alleles for each gene, one from each parent.
What is Codominance pattern of inheritance?
Codominance is a form of inheritance wherein the alleles of a gene pair in a heterozygote are fully expressed. As a result, the phenotype of the offspring is a combination of the phenotype of the parents. Thus, the trait is neither dominant nor recessive.
When a single gene has more than one effect it is called?
Pleiotropy (from Greek πλείων pleion, ‘more’, and τρόπος tropos, ‘way’) occurs when one gene influences two or more seemingly unrelated phenotypic traits. Such a gene that exhibits multiple phenotypic expression is called a pleiotropic gene.
What is the term that refers to the control of several genes as a single unit quizlet?
Polygenic traits refers to any INHERITABLE TRAIT that is controlled by multiple genes, and each of those genes can have multiple alleles.
Are traits controlled by two or more genes?
Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Examples of human polygenic inheritance are height, skin color, eye color and weight. Polygenes exist in other organisms, as well.