Answer: D) retroviruses
Explanation:
Retroviruses are a type of virus that converts its genetic material into DNA using a special enzyme, called reverse transcriptase. The DNA is then able to integrate into the DNA of the host cell. Once integrated, the virus can make additional viral particles using the components of the host cell.
Retroviruses which cause cancer at low incidence do not contain host information inserted. Rather, they tend to cause cancer via the expression mutation of potentially oncogenic host genes. Retroviruses incorporate proviral DNA into their host's chromosomal DNA during their natural life-cycle. Provirus DNA promoter affect regulatory gene expression over.
Hence, the correct option is D.
Alleles can be either dominant or recessive.
Dominant alleles show their effect even if the individual only has one copy of the genes, For example, the allele for brown eyes is dominant, therefore you only need one copy of the 'brown eye' allele to have brown eyes ;although, with two copies you will still have brown eyes.
If both alleles are dominant, it is called co-dominance. The resulting characteristic is due to both alleles being expressed equally. An example of this is the blood group AB which is the result of co-dominance of the A and B dominant alleles.
Recessive alleles only show their effect if the individual has two copies of the allele. For example, the allele for blue eyes is recessive, therefore to have blue eyes you need to have two copies of the 'blue eye' allele.
Illustration showing the inheritance of dominant and recessive alleles for eye colour.
Explanation:
One of the main causes of genetic erosion is the replacement of local varieties by modern varieties. Other causes include environmental degradation, urbanization and land clearing through deforestation and bush fires.
hope it helps!
Answer:
Blood vessels in the heart dilate to increase blood pressure.
<em>Hope this helps!!!</em>
<em>
</em>
