Search results
Results From The WOW.Com Content Network
Heredity of phenotypic traits: a father and son with prominent ears and crowns. DNA structure. Bases are in the centre, surrounded by phosphate–sugar chains in a double helix. In humans, eye color is an example of an inherited characteristic: an individual might inherit the "brown-eye trait" from one of the parents. [1]
Mendelian traits behave according to the model of monogenic or simple gene inheritance in which one gene corresponds to one trait. Discrete traits (as opposed to continuously varying traits such as height) with simple Mendelian inheritance patterns are relatively rare in nature, and many of the clearest examples in humans cause disorders ...
These are characters only expressed in one sex. They may be caused by genes on either autosomal or sex chromosomes. [6] Examples: female sterility in Drosophila; and many polymorphic characters in insects, especially in relation to mimicry. Closely linked genes on autosomes called "supergenes" are often responsible for the latter. [7] [8] [9]
In the example pictured to the right, RRYY/rryy parents result in F 1 offspring that are heterozygous for both R and Y (RrYy). [4] This is a dihybrid cross of two heterozygous parents. The traits observed in this cross are the same traits that Mendel was observing for his experiments. This cross results in the expected phenotypic ratio of 9:3:3:1.
One of the most well-studied examples of infectious heredity is the killer phenomenon exhibited in yeast. Two double-stranded RNA viruses, designated L and M, are responsible for this phenotype. [14] The L virus codes for the capsid proteins of both viruses, as well as an RNA polymerase. Thus the M virus can only infect cells already harbouring ...
Using probabilities, one can then determine which genotypes the parents can create, and at what frequencies they can be created. [16] [18] For example, if two parents both have a heterozygous genotype, then there would be a 50% chance for their offspring to have the same genotype, and a 50% chance they would have a homozygous genotype.
The simplest genetic model involves a single locus with two alleles (b and B) affecting one quantitative phenotype. The number of B alleles can be 0, 1, or 2. For any genotype, ( B i , B j ), where B i and B j are either 0 or 1, the expected phenotype can then be written as the sum of the overall mean, a linear effect, and a dominance deviation ...
The phenotype is a general term that defines an individual's visible, physical traits. The genotype of an offspring is known as its genetic makeup. The alleles of genes can either be dominant or recessive. A dominant allele needs only one copy to be expressed while a recessive allele needs two copies (homozygous) in a diploid organism to be ...