The correct option is C Monozygotic twins
DNA fingerprinting is a laboratory technique which helps in identifying a person based on the unique repetitive sequence in their DNA.
The DNA fingerprint of two individuals is different due to the variation in their genetic makeup. It is due to the number of these variations that every individual has unique DNA sequences.
This leads to the production of DNA fragments of different sizes upon digestion with restriction endonucleases. These DNA fragments are then transferred to agarose gel for gel electrophoresis. This leads to separation of DNA fragments of varying sizes which then get arranged according to their molecular weight.
The separated DNA fragments present in the gel are transferred to a nylon or nitrocellulose membrane, the process called southern blotting. Treatments are given so as to get single strands out of the double stranded DNA that got transferred onto the membrane. To detect the presence of repetitive site locus, a single stranded radioactive probe is used which is complementary to the satellite sequence. The probe is then allowed to hybridise with the DNA on the membrane.
These fragments produce distinctive band patterns when exposed to X rays and analysed on X-ray film called autoradiogram. Hence, DNA fingerprint autoradiogram is usually unique for each individual.
However, monozygotic twins develop from the same zygote. So they have the same genetic make up. Thus, the DNA fragments generated after restriction digestion will be identical. Hence, their DNA fingerprint autoradiogram will also be identical.
Siblings have different genetic make up as they don’t inherit the same DNA from their parents. They are formed due to the fusion of different gametes.
Dizygotic twins develop from two different eggs which get fertilized by different sperms. Hence, they do not have the identical DNA.
A child inherits 50% of DNA from mother and the rest 50% from father. Hence, the genetic material/ DNA content in every cell of the child is not identical to that of the mother. Since, there is a certain percentage of dissimilarity as well, the location of the bands in autoradiograms after DNA fingerprinting would not be identical when compared.