Molecular Basis of Inheritance Test - 3

Griffith carried out experiment on mice using pneumonia causing bacteria to show that DNA is the genetic material by transforming non-virulent strain into virulent strain which is called bacterial transformation.

Enzymes DNA polymerase adds complementary nucleotides. This enzyme is present floating inside the nucleus.

Regulator genes codes for repressor proteins during translation of DNA into protein via mRNA.

In the process of transcription RNA polymerase is only capable of elongation.

Initiation factor sigma helps in the process of initiation while termination factor Rho is helping in termination of the process.

So the correct option is 'Elongation'.

• The distance between 2 consecutive bp is 0.34 nm. The formula to calculate the length of the DNA double helix:
• The length of the DNA double helix = The total number of bp x distance between two consecutive bp.
• As a result, we get 2.2 m as the length of the DNA double helix.

The main purpose of human genome project launched in 1990 was to identify the sequence of human DNA.

Human genome project was associated with the rapid development of new area of biology called as bioinformatics. This branch of biological science is used to known the sequence of gene on Chromosome of living organisms.

Human genome contains 3164.7 million nucleotide bases.

Gel electrophoresis technique is used for separation of DNA fragments according to their size. This is an important tool to study the genome of an individual.

There are 23 pairs of chromosome in human cells. The chromosome Y is the smallest and contain least number of gene (231) and chromosome 1 contain highest number of gene (2968).

About 3% or so of the human genome has highly repetitive sequences or simple-sequence DNA or simple sequence repeats or satellite DNA. It does not encode proteins or RNAs but have identifiable functional importance owing to their presence in centromeres and telomeres; which makes option B wrong as genetic engineering mainly aims at transfer of genes producing desired products. Satellite DNA show relative uniformity within species and great variability between closely related species. This DNA polymorphism is revealed during DNA finger printing in identification of suspect. For the purpose, restriction enzyme digested DNA samples are sorted by gel electrophoresis followed by southern blotting. Finally, radioactive probes are washed over the nylon surface to allow their joining to any DNA fragments of same composition. Correct option is A. Sex determination in human is governed by presence or absence of Y-chromosome, not by satellite DNA which makes option D wrong. Organ transplantation mainly aims at immune system; option C is wrong.

So, the correct answer is 'Forensic science'

• Histones are rich in basic amino acid (AA) residues such as lysine and arginine.
• These two amino acids carry a positive charge at their side chains.
• Due to this reason, histones are called as the set of positively charged basic proteins.

The DNA required for finger printing can be obtained from WBCs, root hair cells and body secretion as all the cells contain same type of genetic makeup.

• Nucleosomes are the bead-like structures which are present on a chromatin.
• These nucleosomes contain the DNA, which is the genetic material.
• Such a typical nucleosome contains nearly 200 bp.

The double helix describes the appearance of double-stranded DNA, which is composed of two linear strands that run opposite to each other, or anti-parallel, and twist together. Each DNA strand within the double helix is a long, linear molecule made of smaller units called nucleotides that form a chain.