Question

Gene library refers to
A. DNA sequence information maintained in the data bank.
B. DNA fragments maintained in agarose gel.
C. DNA fragments of a genome-maintained cloning in cultured cells.
D. Photographs of DNA fragments printed in books.

Answer 1

Hint: As we already know that genes are short sequences of DNA, deoxyribonucleic acid packed in long strands of DNA. Many strands of DNA form chromosomes and they are tightly packed with proteins inside a cell. Genes contain all the genetic information which is being transferred from generation to generation. Hence, the gene library refers to a collection of genes.

Complete answer:
Option A) DNA sequence information maintained in the data bank- DNA sequence is stored in long sequences and maintained in the data bank. DNA sequences are placed in compact structures. Gene data are stored in large files and maintained in records for future use.
So, option A is not correct.
Option B) DNA fragments maintained in agarose gel- DNA fragments are nothing but short sequences of DNA which are sliced or chopped by restriction enzymes and are stored in agarose gel. Agarose gel is a medium in which DNA travels towards an electrode to show banding. This process is termed as gel electrophoresis. The technique is used to determine DNA size.
So, option B is not correct.
Option C) DNA fragments of a genome-maintained cloning in cultured cells- Gene library is a collection of fragments of DNA from an organism. They contain the entire genomic sequence or complementary DNA sequences which can be used to identify and maintain the data records of genes.
So, option C is correct.
Option D) Photographs of DNA fragments printed in books- DNA fragments are never kept as photographs if suppose they have kept for record purpose or kind of museum. As DNA are proteins or macromolecules, they have their own fidelity.
So, option D is not correct.

Hence, Option C is the correct answer.

Note:
There are different types of genomic libraries, and all can be studied in recombinant DNA technology. One such is- complementary DNA libraries, genomic libraries and random mutant libraries. DNA libraries are basically constructed by adding genes of interest to DNA fragments which have been cleaved by restriction enzymes. Everyone has a separate genome for their purpose.