Tag: genetic technology

Questions Related to genetic technology

Human insulin is being commercially produced from a transgenic species of

  1. Mycobacterium

  2. Rhizobium

  3. Saccharomyces

  4. Escherichia


Correct Option: D
Explanation:

A transgenic microorganism is a microbe, usually a bacterium, into which genetic information has been introduced from the outside and which possesses the ability to pass that information on to subsequent generations. In this process by which, scientists introduce new genetic material into a microorganism is called as molecular or gene cloning. It involves the isolation of DNA from a source other than the microorganism itself. The human insulin is produced by genetically engineered Escherichia coli.

Thus, the correct answer is option D. 

When using bacteria to clone a human gene and express its product-as in the case of insulin-the gene cannot contain introns because bacteria do not have the enzymes to process mRNA. Therefore

  1. if the sequence is known, very small human genes can be built with a DNA synthesizer in a laboratory and they will lack introns

  2. reverse transcriptase can be used to make DNA backwards from human mature mRNA and this would lack introns

  3. it is impossible to use bacteria to express human gene products because all human genes have introns

  4. both (a) and (b) are true


Correct Option: D
Explanation:

In order for a human gene to be expressed in bacteria, it must have one important modification. Specifically, it must lack introns. Introns are intervening sequences found in many human genes, and they are removed from eukaryotic RNA transcripts by splicing to make a mature mRNA. Bacteria lack enzymes for splicing. This problem is tackled by using the following approaches:- 

  1. Reverse transcriptase is used to make DNA backwards from human mature mRNA. This DNA will lack introns and DNA will contain only those genes that are going to be expressed. 
  2. Artificial gene synthesis by building polynucleotide chain based on the sequence of nucleotides in DNA fragment of the gene of interest. 

So, the correct option is 'both (a) and (b) are true'. 

Some of the steps involved in the production of humilin are given below. Arrange them in the correct sequence and select the correct option.
(i) Synthesis of gene (DNA) for human insulin artificially
(ii) Culturing recombinant E.coll in bioreactors 
(iii) Purification of humilin
(iv) Insertion of human insulin gene into plasmid
(v) Introduction of recombinant plasmid into E.coli 
(vi) Extraction of recombinant gene product from E.coli.

  1. (ii), (i), (iv), (iii), (v), (vi)

  2. (i), (iii), (v), (vi), (ii), (iv)

  3. (i), (iv), (v), (ii), (vi), (iii)

  4. (iii), (v), (ii), (i), (vi), (iv)


Correct Option: C
Explanation:

The given sentences can be arranged in a systemic order of i, iv, v, ii, vi, iii.

So, the correct option is '(i), (iv), (v), (ii), (vi), (iii)'.

Which of the following is produced by genetic engineered bacteria?

  1. thyroxine

  2. insulin

  3. glucagon

  4. ADH


Correct Option: B
Explanation:

Genetically modified or Genetically engineered bacteria were the first organisms to be modified in the laboratory, due to their simple genetics. These organisms are now used for several purposes and are particularly important in producing large amounts of pure human proteins for use in medicine. Insulin is normally produced by it.

So, the correct option is 'insulin'.

During the processing of the prohormone "proinsulin" into the mature "insulin".

  1. C-peptide is added to proinsulin

  2. C-peptide is removed from proinsulin

  3. B-peptide is added to proinsulin

  4. B-peptide is removed from proinsulin


Correct Option: B
Explanation:

Both C-Peptide and mature insulin are biologically active. Cell components and proteins in this image are not to scale. Proinsulin is the prohormone precursor to insulin made in the beta cells of the islets of Langerhans, specialized regions of the pancreas. In humans, proinsulin is encoded by the INS gene.

So, the correct option is 'C-Peptide is removed from proinsulin'.

The first human hormone produced by recombinant DNA technology is?

  1. insulin

  2. estrogen

  3. thyroxin

  4. progesterone


Correct Option: A
Explanation:

The first licensed drug generated using recombinant DNA technology was human insulin, developed by Genentech and Licensed by Elli Lilly and company.

So, the correct option is 'Insulin'.

Which of the following is required for microinjection method of gene transfer?

  1. Microparticles

  2. Micropipettes

  3. Divalent cations

  4. UV radiations


Correct Option: B
Explanation:
Micro-injection method is the direct or vectorless method of gene transfer, in which foreign DNA is directly injected into the nucleus of animal cell or plant cell by using micro-needles or micro-pipettes. It is used to transfer DNA in oocytes, eggs and embryo.
So, the correct answer is 'Micropipettes'.

The term "competent" refers to

  1. Increasing the competition between cells

  2. Making cells impermeable for DNA

  3. Increasing the efficiency with which DNA enters the bacterium through pores in its cell wall

  4. Making cells permeable for divalent cations


Correct Option: C
Explanation:
Transformation is a process by which a cell takes up naked DNA fragment from the environment, incorporates it into its own chromosomal DNA and finally expresses the trait controlled by the incoming DNA. Since DNA is a hydrophilic molecule, it can not pass through membranes, so the bacterial cells must be made competent to take up DNA. This is done by treating them with a specific concentration of a divalent cation, such as calcium ($Ca^{2+}) which increases the efficiency with which DNA enters the bacterium through pores in its cell wall.
So, the correct answer is 'Increasing the efficiency with which DNA enters the bacterium through pores in its cell wall'.

Micro-injection is a method used to

  1. Produce sticky ends of DNA

  2. Provide protection against pathogen

  3. Purify the DNA

  4. Inject recombinant DNA into the nucleus of an animal cell


Correct Option: D
Explanation:

Micro-injection is a method used to Inject a recombinant DNA into the nucleus of an animal cell. This is the only way to introduce alien DNA into host cells. 

So, the correct option is 'Option D' .

If a recombinant DNA bearing gene for resistance to antibiotic ampicillin is transferred to E.coli cells, the host cells become transformed into ampicillin-resistant cells. If such bacteria are transferred on agar plates containing ampicillin, only transformants will grow and the untransformed recipient cells will die. The product produced by transformant bacteria that digests the ampicillin antibiotic is called as - 

  1. Selectable marker

  2. Recombinant protein

  3. Cloning site

  4. Chemical scalpels


Correct Option: B