What is cryptic variation?
Cryptic genetic variation (CGV) is defined as standing genetic variation that does not contribute to the normal range of phenotypes observed in a population, but that is available to modify a phenotype that arises after environmental change or the introduction of novel alleles.
What are cryptic genes?
Cryptic genes are phenotypically silent DNA sequences, not normally expressed during the life cycle of an individual. They may, however, be activated in a few individuals of a large population by mutation, recombination, insertion elements, or other genetic mechanisms.
What is a cryptic phenotype?
What is cryptic genetic variation? Cryptic genetic variation refers to unexpressed, bottled-up genetic potential. It is not normally seen, but is expressed under abnormal conditions such as in a new environment or a different genetic background.
How does mutations affect genetic variation?
Mutations can introduce new alleles into a population of organisms and increase the population’s genetic variation.
What is the canalization principle?
The concept of canalization requires that stabilizing selection can alter the tendency of a developmental system to vary. In other words, stabilizing selection must be able to affect the responsiveness of a developmental system to genetic and environmental changes.
What is geographic variation?
Geographical variation refers to differences among populations in genetically based traits across the natural geographic range of a species. Understanding the factors that give rise to and maintain geographical variation helps elucidate the causes and consequences of evolution.
Can genes be overlapping?
Overlapping genes are relatively common in DNA and RNA viruses (5-9). While several examples exist in bacterial and eukaryotic genomes, overlapping genes appear to be relatively rare in non-viral organisms and few reports have described overlapping genes in mammalian genomes (10-12).
What is split gene in biology?
An interrupted gene (also called a split gene) is a gene that contains expressed regions of DNA called exons, split with unexpressed regions called introns (also called intervening regions). Exons provide instructions for coding proteins, which create mRNA necessary for the synthesis of proteins.
What are the 3 sources of mutations?
There are three types of DNA Mutations: base substitutions, deletions and insertions.
What is the difference between a variation and a mutation?
Genetic variation refers to diversity in gene frequencies. Genetic variation can refer to differences between individuals or to differences between populations. Mutation is the ultimate source of genetic variation, but mechanisms such as sexual reproduction and genetic drift contribute to it as well.
What is a plastic response?
1, p. 142) of environmentally induced phenotypes or plastic responses. Plastic responses can be described by a “plasticity vector” that quantifies the change in mean phenotypic trait values between two environments, expressed as the distance between the multivariate phenotype means.
What is the medical definition of a mutation?
Medical Definition of mutation. : a relatively permanent change in hereditary material that involves either a change in chromosome structure or number (as in translocation, deletion, duplication, or polyploidy) or a change in the nucleotide sequence of a gene’s codons (as in frameshift or missense errors) and occurs either in germ cells…
When is a duplication mutation called a forward mutation?
Duplication– when some bases or a base duplicated in a gene sequence. The image shows the type of duplication mutation in a DNA sequence. Genetic Mutation from wild-type to mutant or evolution of new mutation from wild-type allele is called a forward mutation. The forward mutation leads to the evolution of new traits in the population.
When does a mutation change the wild type to a mutant type?
When a mutation changes the wild type normal genotype to a mutant type, as is more often the case, the event is called a forward mutation. This is in contrast to reverse mutations in which the mutant genotype changes to the original wild type.
Which is an example of a base substitution mutation?
Substitution– When some bases of a gene sequence are replaced by other bases. The image shows the type of base substitution mutation in a DNA sequence. Duplication– when some bases or a base duplicated in a gene sequence. The image shows the type of duplication mutation in a DNA sequence.
