Repetitive dna elements a. may be tandem or spread across several chromosomes. b. are found in centromeres and telomeres. c. make up nearly half of human chromosomes. d. may be present as just a few or many thousands of copies. e. all of these are correct.

e. All of these are correct.

Explanation:

Repetitive DNA element consists of tandem, repeated sequences involving two to several thousand base pairs. It consists of about nearly 50% of the entire genome of the human body. Most of these sequences are located in the telomeres and centromeres, but these are also distributed throughout the genome. The repetitive DNA sequence is also called as satellite DNA as it was discovered as small satellite band during the process of density gradient centrifugation.

On the basis of the above description, all of the given options are correct.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.