does it causes changes in gene?
Yes, it can. However, it depends on the its effect on genetic diversity. “Purifying" selection acts to remove genetic variation and "de novo” mutation can lead to a new variation.
Natural selection
Alternatively, selection can be divided according to its effect on genetic diversity. Purifying or negative selection acts to remove genetic variation from the population (and is opposed by "de novo" mutation, which introduces new variation.
when does the genetic material of a host and a virus combine Only when the host is infected by the virus. can you please define the latter term? It is a submicroscopic infectious agent that replicates only inside the living cells of an organism. how did it get its name? From the Latin word ”Virulent” that refers to poison. what features of life do they exhibit? They resemble organisms in a way that they possess genes, evolve by natural selection, and reproduce by creating multiple copies of themselves through self-assembly. However, they do not have a cellular structure, which is often seen as the basic unit of life. can you describe this process of evolving that you just mentioned? It is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.
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Natural selection [SEP] By effect on genetic diversity
Alternatively, selection can be divided according to its effect on genetic diversity. Purifying or negative selection acts to remove genetic variation from the population (and is opposed by "de novo" mutation, which introduces new variation. In contrast, balancing selection acts to maintain genetic variation in a population, even in the absence of "de novo" mutation, by negative frequency-dependent selection. One mechanism for this is heterozygote advantage, where individuals with two different alleles have a selective advantage over individuals with just one allele. The polymorphism at the human ABO blood group locus has been explained in this way.