Question

Satellite DNA is a useful tool in
A. Sex determination
B. Forensic engineering
C. Genetic engineering
D. Organ transplantation

Answer 1

Hint: Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. Satellite DNA is the main component of functional centromeres and forms the main structural constituent of heterochromatin.

Complete answer:
Satellite DNA refers to the repetitions of a short DNA sequence that produce a different frequency of the nitrogenous bases. Different combinations of bases have a different density from normal DNA and form a second or satellite band when genomic DNA is separated on a density gradient. About 3% or so of the human genome has highly repetitive sequences or simple-sequence DNA or simple sequence repeats with less than 10 bp long-short sequences, repeated in multiples times per cell.

Satellite DNA shows relative uniqueness within species and great variability between closely related species. Also, different individuals differ in the number of repeats of ssDNA. Satellite DNA is a region that possesses several short DNA sequences repeated multiple times. The variation between individuals in the lengths and number of such repeats the satellites forms are unique to the individual and form the basis of DNA fingerprinting. The length and the number of each satellite structure within a DNA are inherited. The length of the satellite regions is highly variable and extensively unique for different individuals.

Hence, the correct answer is Option B.

Note: DNA fingerprinting makes use of the uniqueness of the repeats to identify individuals and estimate relatedness. The probe used in DNA fingerprinting is called the VNTR or STR which stands for a variable number of tandem repeats and small tandem repeats. Sex determination is done using a technique called chromosome walking from the amniotic fluid of a pregnant mother. Organ transplantation primarily revolves around a specific set of genes that code for the MHC (major histocompatibility complex) which reveals where the donor and the recipient are compatible.