Biotechnology: Principles and Processes

Which vector can clone only a small fragment of DNA ?

1. Cosmid
2. Bacterial artificial chromosome
3. Yeast artificial chromosome
4. Plasmid

The colonies of recombinant bacteria appear white in contrast to blue colonies of non-recombinant bacteria because of :

1. Insertional inactivation of alphagalactosidase in recombinant bacteria
2. Inactivation of glycosidase enzyme in recombinant bacteria
3. Insertional inactivation of alphagalactosidase in non-recombinant bacteria
4. Non-recombinant bacteria containing betagalactosidase

DNA fragments generated by the restriction endonucleases in a chemical reaction can be separated by :

1. Polymerase chain reaction
2. Restriction mapping
3. Electrophoresis
4. Centrifugation

Which of the following is not correctly matched for the organism and its cell wall degrading enzyme ?

1. Plant cells- Cellulase
2. Algae-Methylase
3. Fungi - Chitinase
4. Bacteria-Lysozyme

Genes of interest can be selected from a genomic library by using :

1. Restriction enzymes
2. Gene targets
3. Cloning vectors
4. DNA probes

During the process of isolation of DNA, chilled ethanol is added to :

1. Break open the cell to release DNA
2. Remove proteins such as histones
3. Facilitate action of restriction enzymes
4. Precipitate DNA

Biolistics (gene-gun) is suitable for

1. DNA finger printing
2. Constructing recombinant DNA by joining with vectors
3. Disarming pathogen vectors
4. Transformation of plant cells

In genetic engineering, the antibiotics are used

1. As sequences from where replication starts
2. As selectable markers
3. To keep the cultures free of infection
4. To select healthy vectors

Which one of the following represents a palindromic sequence in DNA ?

1. 5′-GAATTC-3′ 3′-CTTAAG-5′
2. 5′-GATACC-3′ 3′-CCTAAG-5′
3. 5′-CCAATG-3′ 3′-GAATCC-5′
4. 5′-CATTAG-3′ 3′-GATAAC-5′

The figure below shows three steps (A, B, C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents ? [figure]

1. C - Extension in the presence of heat stable DNA polymerase
2. B - Denaturation at a temperature of about 98 separating the two DNA strands
3. A - Denaturation at a temperature of about 50
4. A - Annealing with two sets of primers