Biotechnology: Principles and Processes · Question 52

Choose the correct pair from the following

1. Exonucleases – Make cuts at specific positions within DNA
2. Ligases – Join the two DNA molecules
3. Polymerases – Break the DNA into fragments
4. Nucleases – Separate the two strands of DNA

DNA precipitation out of a mixture of biomolecules can be achieved by treatment with :

1. Methanol at room temperature
2. Chilled chloroform
3. Isopropanol
4. Chilled ethanol

Following statements describe the characteristics of the enzyme Restriction Endonuclease. Identify the incorrect statement.

1. The enzyme cuts the sugar-phosphate backbone at specific sites on each strand
2. The enzyme recognizes a specific palindromic nucleotide sequence in the DNA
3. The enzyme cuts DNA molecule at identified position within the DNA
4. The enzyme binds DNA at specific sites and cuts only one of the two strands

Which one of the following equipments is essentially required for growing microbes on a large scale, for industrial production of enzymes?

1. Industrial oven
2. Bioreactor
3. BOD incubator
4. Sludge digester

The correct order of steps in Polymerase Chain Reaction (PCR) is

1. extension, denaturation, annealing
2. annealing, extension, denaturation
3. denaturation, extension, annealing
4. denaturation, annealing, extension

The DNA fragments separated on an agarose gel can be visualised after staining with

1. Bromophenol blue
2. Aniline blue
3. Ethidium bromide
4. Acetocarmine

DNA fragments are

1. Positively charged
2. Either positively or negatively charged depending on their size
3. Neutral
4. Negatively charged

A gene whose expression helps to identify transformed cell is known as

1. Selectable marker
2. Plasmid
3. Vector
4. Structural gene

What is the criterion for DNA fragments movement on agarose gel during gel electrophoresis ?

1. Positively charged fragments move to farther end
2. Negatively charged fragments do not move
3. The smaller the fragment size, the farther it moves
4. The larger the fragment size, the farther it moves

The process of separation and purification of expressed protein before marketing is called :

1. Upstream processing
2. Bioprocessing
3. Downstream processing
4. Postproduction processing