What is dominant lethal allele?

Answer 1

Dominant lethal is a genetic trait. If the genome of an individual has the trait, it is expressed and makes it impossible for the individual to have descendants. Its effects cause foetal or embryonic death.

Answer 2

A lethal allele is one that results in the death of the organism.

For all practical purposes dominant alleles that require only one copy of the allele to result in death are eliminated from the population and are probably the result of a single point mutation.

Most lethal alleles that occur with any frequency within a population are recessive or, if dominant, require 2 copies of the dominant allele for a lethal effect. This means that the bulk of the alleles are present in heterozygous individuals. Other lethal alleles are

associated with the sex chromosomes and affect male children more frequently than

female children.

Examples of lethal alleles:

1.LWO (lethal white overo) in horses. One copy of the allele results in a nifty spotting pattern called Overo/Frame Overo. Two copies result in a white foal that dies shortly after birth due to a nonfunctional gastrointestinal tract. This is a dominant trait that requires 2 copies of the dominant allele to be lethal.

2.Acondroplastic Dwarfism in humans. One copy of the allele results in a specific form of dwarfism. Two copies are lethal, resulting in offspring that cannot breathe due to lack of cartilage in the ribcage. Another dominant trait that requires 2 copies to be lethal.

3.Hemophilia a recessive trait located on the X chromosome. Male children, having only one X-chromosome have a 50-50 chance of inheriting the lethal allele from

a mother who is a carrier. The trait is recessive so the father would have to have the

disease and the mother be a carrier in order to produce a daughter who is similarly

affected.

4. Sickle-Cell Anemia. A non-dominant trait that, in the heterozygous configuration confers some resistance to malaria. In the homozygous individual sickle shaped red blood cells have difficulty carrying adequate oxygen and can clump together preventing adequate blood flow. Heterozygous individuals have a combination of normal and easily deformed cells often with no ill effects at low altitudes.

While modern medical intervention can prolong the lives of many individuals who would otherwise die without treatment the baseline lethality of many genetic disorders remains.

Answer 3

An allele that has power over a recessive allele

Answer 4

A dominant lethal allele is a gene that causes death. An individual need only have one allele to die.

Answer 5

Since we inherit genes and not traits, the dominant allele might contain the genes that increase risk for disease or disorder. Genetic disorders most often occur in early human development.

Answer 6

a type of genetic mutation that proves to be deadly