In human gene therapy, a genetically modified virus (a.k.a. a viral vector) can alter the genetic variation of a cell, but not all viral vectors do.
The process often begins with the delivery of or creation of a segment of viral double stranded DNA (containing the gene you want to introduce). Then typically an enzyme known as an integrase cuts the ends of the segment of viral DNA and also cuts open the cell's DNA. Then the viral DNA is integrated/ inserted into the cell's DNA. The connecting ends are ligated together and adjusted so that the nucleotide base pairs match up.
This in the future may affect the gene pool for instance if the viral DNA (your gene) was inserted in the middle of another gene or important regulatory sequence of the cell DNA, and this alteration may be passed on into offspring and become present in the gene pool, which could have bad effects.
The effects on the gene pool really depends on what the virus ends up doing. For example, it may fix the function of a damaged gene which is the goal, and allow for a working gene to be in the gene pool, which would be good. The problem with gene therapy is that it's difficult to predict 100% what the virus will do every time it is given to a patient.
But it's very important to consider that it will only affect the gene pool if the virus is able to enter and alter germ cells (reproductive cells). If the virus, enters somatic cells (regular body cells) this will not be passed on to future generations. So viruses can be designed to avoid germ cells and avoid this gene pool issue. Also, some viral vectors use viruses that do not integrate their DNA, the cells just express the viral DNA (create the desired protein from it) and over time the viral DNA is degraded/ lost which wouldn't pose this threat.
This is long, but I hope it helped!
Answer:
are influenced by many different genes
Explanation:
A quantitative trait is a given phenotypic trait influenced by the combined effects of many genes and its environment. A quantitative trait locus (QTL) is a region of DNA (i.e., a <em>locus</em>) associated with the variation of a quantitative trait. In the last years, some QTLs correlated to the variation of HDL, LDL, and triglycerides levels were mapped in different genomic regions, thereby showing that these complex traits are regulated by the interaction of multiple genetic <em>loci</em>.
Answer:
Abnormal BRCA1 and BRCA2 genes are found in 5% to 10% of all breast cancer cases in the United States. A study found that women with an abnormal BRCA1 gene had a worse prognosis than women with an abnormal BRCA2 gene 5 years after diagnosis.
Explanation:
In living things, there are 6 common elements that can be found: carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus. Among these, the major ones are carbon, hydrogen, oxygen and nitrogen.
The most important of all that characterizes organic matter from the rest, is the presence of carbon. Carbon is a versatile element because it can bond to itself to an unlimited length. Because of this, it makes itself as host to other functionalities like hydroxide, amines and many more. The combination of a length of carbon chains with other of these major elements make up the basic compounds that our body needs. Compounds like carbohydrates, lipids, hormones, proteins and even our DNA and RNA strands are made up of these major elements.
