Manipulation of DNA by cells?

The simple answer is yes, such processes do exist. The most obvious example would be in the B and T cells of the immune system where the genome of individual cells are rearranged to form novel genetic combinations coding for antibodies. This process, V(D)J recombination, both selects a random combination of pre-existing genes coding for sections of the antibody, deleting those it doesn't use from the cell's genome, and also adds additional random sequences which vastly increase the variability of the resulting antibodies.Of course this particular mechanism is only found in the immune system of vertebrates and is limited to somatic tissues, so none of these changes will be inherited by the organism's offspring.There are other more problematic mechanisms which are sometimes suggested to be forms of this, we have had a couple of previous threads which have brought up several examples, Wright et al. on the Process of Mutation, Message 643, Message 776. Most of these are confined to unicellular organisms however.TTFN,WK

Not really, antibodies can pass across the placenta and provide protection to the fetus but cells with the genetic sequence corresponding to those antibodies will not pass to the fetus. As with the antibodies in colostrum this is a temporary immunity which will be lost over time as the child's own immune system develops.TTFN,WK