What is base modifier?

Chemical that react with DNA bases ( base modifiers ) These chemical react directly with the nucleotide bases , altering the chemical structure as examples:-

What are the examples of chemical mutagens?

Most chemical mutagens are alkylating agents and azides. Physical mutagens include electromagnetic radiation, such as gamma rays, X rays, and UV light, and particle radiation, such as fast and thermal neutrons, beta and alpha particles.

What are 4 examples of mutagens?

Examples of mutagens include radioactive substances, x-rays, ultraviolet radiation, and certain chemicals.

What is a rate modifier?

An Experience Modification Rate (EMR) has a significant impact on the worker’s compensation insurance premium of a business. The EMR is a metric that insurers use to calculate worker’s compensation premiums; it takes into account the number of claims/injuries a company has had in the past and their corresponding costs.

How do modifier genes work?

Genetic modifiers, defined as genetic variants that can modify the phenotypic outcome of the primary disease-causing variant, are one such example. They can increase (known as an enhancer) or decrease (known as a suppressor) the severity of the disease condition but may not be disease-causing themselves.

What are called chemical mutagens?

Chemical mutagens are standard tools for mutagenesis in a variety of organisms, and they are a primary means of creating mutations in phenotype-based screens in most genetic systems.

What is a modifier variant?

Modifier variants can change a target gene’s phenotype by having a genetic, biochemical, or functional interaction with one or more target gene(s), or gene product(s) [15]. The degree of the effect of the modifiers can vary, which may result in large phenotypic variability and changes in penetrance.

What are disease modifiers?

Disease modifiers are genes that when activated can alter the expression of a phenotype associated with a disease. This can be done directly through affecting the expression of another gene that is causing the disease, or indirectly by affecting other factors that contribute to the phenotype’s variability.

What are the four types of chemical mutagens?

The chemical mutagens can be divided into four groups, viz.: 1 (1) Alkylating agents, 2 (2) Base analogues, 3 (3) Acridine dyes, and 4 (4) Others (Table 25.3).

How are base analogues used in chemical mutagens?

Some of the chemical mutagens and mutagenesis are given in Table 9.3, and described below: i. Base Analogues: A base analogue is a chemical compound similar to one of the four bases of DNA. It can be incorporated into a growing polynucleotide chain when normal process of replication occurs.’

What kind of mutagen can replace thymidine in DNA?

The 5-bromodeoxyuridine (5-BDU) can replace thymidine in DNA molecule. The 2-amino-purine (2-AP) and 2, 6-di-amino-purine (2, 6-DAP) are the purine analogues. The 2-AP normally pairs with thymine but it is able to form a single hydrogen bond with cytosine resulting in transition of AT to GC.

How are mutagens used to change specificity of hydrogen bonding?

There are many chemicals that after incorporation into DNA change the specificity of hydrogen -bonding. Those which are used as mutagens are nitrous oxide (HNO 2 ), hydroxylamine (HA) and ethyl-methane-sulphonate (EMS). Nitrous oxide converts the amino group of bases into keto group through oxidative deamination.