Transposable elements are discrete segments of DNA that can be excised and reintegrated to another site in the genome, these can inactivate the gene in which they reside, cause chromosome breaks, and / or transpose to a new location within the genome.
Explanation:
Transposable elements are fragments of DNA that have the ability to jump from one part of the genome to another. While most of the DNA is always in the same place surrounded by the same neighboring pieces of DNA, mobile elements move from one place to another causing many changes or mutations. When a transposon moves through the genome, it can insert into a vital gene, disrupting its function, or into a location near vital genes, causing erroneous activation or inactivation.On the other hand, there can be chromosomal rearrangements due to transposons of the same family with complementary sequences that are separated in the genome and that by sequence homology match. This can lead to ectopic recombination. Large-scale rearrangements induced by mobile elements are considered a particular class of recombination events that influence genomic plasticity.
You are looking at tissue under a microscope. One cell shows half the amount of DNA of some of the other cells. This cell is most likely to be in the G1 phase where the cell has just divided. Hope this answers the question. Have a nice day.