The mutagens that result in cancer damage DNA by (b) weakening the DNA strand or interfering with base pairing. This mutagens are called carcinogens, if they cause a damage to <span>a gene that makes a </span>DNA<span> repair protein, it means that a cell will have less ability to repair itself, and ,as a result, this will lead to formation of cancer.</span>
Answer:
The reason for this is that both moss and fern species are relatively primitive plants that are only Imperfectly adapted to a terrestrial environment. ferns have both roots and vascular tissue and therefore, can grow larger than moss species, but like the mosses, ferns require water for reproduction.
Transposable elements are considered to be responsible for vast range of genome diversity and gene silencing.
Explanation:
Transposable elements are short sequences of DNA that have the ability to move from one location to another in the genome. During this process they copy themselves.
The entire process carried out by transposable elements to copy themselves and move from one location to another is called transposition.
Transposition may result in mutation and is potentially a major source of genome diversity and change. If a transposon inserts itself into the coding region of a gene,it interrupts the coding sequence and inactivates the gene expression.
In addition to this, a transposable element may contain transcription or translation termination signal that will block the gene expression downstream of insertion site.
Sickle cell disease has a benefit in malaria infection because it makes the parasites easier to eliminate. This makes a person with sickle cell disease is more likely to survive the malaria infection, which found many in Africa.
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Sickle cell disease has a few drawbacks because it makes the red blood cells less durable, which lead to the destruction of more red blood cells. In normal condition(where malaria doesn't exist like in America), this gene will make the organism less likely to survive than those who don't have the gene.</span>