0
How do dominant lethal alleles persist in populations even though their fitness is essentially zero?
Huntington's disease, where the lethal allele expresses itself very late in an individuals life. Persons carrying the dominant lethal allele does not become aware of the disease until after their reproductive age. Thus, they pass the lethal allele to their children without knowing and the allele persists.
What else can I help you with?
What is a detrimental gene?
A deleterious mutation has a negative effect on the phenotype, and thus decreases the fitness of the organism. (A harmful mutation)
What breeding crosses parents with the same or similar set of alleles?
Inbreeding is the breeding practice that crosses parents with the same or similar set of alleles. This can result in an increased expression of harmful recessive traits due to the increase in homozygosity. Inbreeding is commonly used in plant breeding to create pure lines, but can lead to decreased genetic diversity and fitness in populations.
What does it mean if there is two different alleles for a great?
If there are two different alleles for a trait, it means that the individual is heterozygous for that gene. One allele may be inherited from each parent, resulting in genetic variation. Depending on the dominance relationship between the alleles, one may be expressed over the other (dominant) or they may both contribute to the phenotype (co-dominance or incomplete dominance). This genetic diversity can influence traits such as physical characteristics, disease resistance, and overall fitness.
What is the heterozygous advantage?
Heterozygous advantage refers to a genetic phenomenon where individuals with two different alleles for a specific gene (heterozygotes) have a higher fitness or survival rate compared to those with two identical alleles (homozygotes). This advantage often occurs in the context of certain diseases; for example, individuals who are heterozygous for the sickle cell trait are more resistant to malaria while not suffering severe symptoms associated with sickle cell disease. This concept helps explain the maintenance of genetic diversity within populations, as it can favor the persistence of certain alleles in the gene pool.
What type of selection always results in the narrowing of the bell curve distribution of alleles?
Directional selection always results in the narrowing of the bell curve distribution of alleles. This occurs when individuals at one extreme of the phenotypic range have a higher fitness, causing the frequency of the alleles associated with that extreme to increase in the population over time.
What is a detrimental gene?
A deleterious mutation has a negative effect on the phenotype, and thus decreases the fitness of the organism. (A harmful mutation)
Are dominant alleles always more common?
A honozygous gene will be expressed, but not necessarily because it is dominant; it would be expressed because there is no alternative. If I ask you to pick one of two cards, and they are both the jack of diamonds, what card will you pick? To know if a gene is dominant you have to find out if it actually will be expressed even when there is a different gene for that trait, with which it is paired.
What breeding crosses parents with the same or similar set of alleles?
Inbreeding is the breeding practice that crosses parents with the same or similar set of alleles. This can result in an increased expression of harmful recessive traits due to the increase in homozygosity. Inbreeding is commonly used in plant breeding to create pure lines, but can lead to decreased genetic diversity and fitness in populations.
What does it mean if there is two different alleles for a great?
If there are two different alleles for a trait, it means that the individual is heterozygous for that gene. One allele may be inherited from each parent, resulting in genetic variation. Depending on the dominance relationship between the alleles, one may be expressed over the other (dominant) or they may both contribute to the phenotype (co-dominance or incomplete dominance). This genetic diversity can influence traits such as physical characteristics, disease resistance, and overall fitness.
What is the definiyion of heterezygous?
Heterozygous refers to an organism that has two different alleles for a specific gene, one inherited from each parent. For example, if one allele is dominant and the other is recessive, the organism will display the trait associated with the dominant allele. This genetic variation can contribute to diversity in traits within a population. Heterozygosity is important in genetics as it can influence an organism's adaptability and overall fitness.
How do the muscles of a dominant individual differ from those of a non-dominant individual?
The muscles of a dominant individual are typically stronger and more developed compared to those of a non-dominant individual. This is often due to regular exercise, physical activity, and a higher level of fitness in dominant individuals.
Why gene flow among populations reduces the potential for local adaptation within each population?
Gene flow among populations introduces new genetic material, which can dilute or homogenize the unique adaptations that have evolved in response to local environmental conditions. When individuals from different populations interbreed, the advantageous alleles that are specific to a particular environment may be lost or reduced in frequency, thereby diminishing the population's ability to adapt to its specific niche. This mixing of genetic material can lead to a decrease in local fitness and may hinder the evolutionary trajectory of populations that are well-suited to their habitats.
What is caused by gene flow?
When genes are exchanged due to the mixing of populations, the result is gene flow. Genetic drift, along with natural selection, mutation, and migration, is one of the basic mechanisms of evolution.
How is the sickle-cell allele maintained through natural selection?
Heterozygous induviduals pass the dominant and recessive alleles to offspring
What is the heterozygous advantage?
Heterozygous advantage refers to a genetic phenomenon where individuals with two different alleles for a specific gene (heterozygotes) have a higher fitness or survival rate compared to those with two identical alleles (homozygotes). This advantage often occurs in the context of certain diseases; for example, individuals who are heterozygous for the sickle cell trait are more resistant to malaria while not suffering severe symptoms associated with sickle cell disease. This concept helps explain the maintenance of genetic diversity within populations, as it can favor the persistence of certain alleles in the gene pool.
Harmful or helpful is considered to be the source for new alleles and a main contributor to the diversity of life on Earth?
Both harmful and helpful mutations contribute to the diversity of life on Earth by introducing new alleles into a population. Harmful mutations may reduce an organism's fitness, while helpful mutations can provide a selective advantage. Over time, these mutations drive evolution by shaping the genetic diversity of populations.
What type of selection always results in the narrowing of the bell curve distribution of alleles?
Directional selection always results in the narrowing of the bell curve distribution of alleles. This occurs when individuals at one extreme of the phenotypic range have a higher fitness, causing the frequency of the alleles associated with that extreme to increase in the population over time.
