Tag: option b: biotechnology and bioinformatics

Questions Related to option b: biotechnology and bioinformatics

Identify the correct sequence of steps in the construction of recombinant DNA.
$(1)$ use restriction enzymes
$(2)$ use DNA ligase
$(3)$ remove plasmid from parent bacterium
$(4)$ introduce plasmid into new host bacterium.

  1. $1-2-3-4$

  2. $4-3-2-1$

  3. $3-1-2-4$

  4. $2-3-1-4$


Correct Option: D
Explanation:
Generation  of rDNA steps:
1) The DNA for insulin is first disengaged. 
2) A plasmid made of DNA is expelled from a bacterial cell. 
3) A limitation protein cuts the plasmid DNA open, leaving sticky finishes. 
4) The insulin quality, with integral sticky closures, is included. 
5) DNA ligase catalyst grafts (joins) together with the plasmid DNA and the Insulin DNA. 
6) The plasmid (now hereditarily changed) is embedded again into the bacterium. 
7) The bacterium has cell, partitions and delivers duplicates of the plasmid. 
8) The Bacterium makes human insulin utilizing the quality in the plasmid. 
9) The insulin is removed from the bacterial culture.
So, the correct option '2−3−1−4'.

The first plasmid used for recombinant DNA technology is obtained from

  1. Bacillus thurinegenesis

  2. Thermus aquaticus

  3. Salmonella typhimurium

  4. E. Coli


Correct Option: B

The process by which restriction endonuclease cut the DNA molecule?

  1. Reduction

  2. Oxidation

  3. Hydrolysis

  4. Carboxylation


Correct Option: A

In E.coli, a finished polypeptide has $162$ amino acids of which the first amino acid is not methionine compound. How many nucleotides of DNA are required to code this polypeptide?

  1. $486$

  2. $54$

  3. $489$

  4. $492$


Correct Option: A

The technique in which a foreign DNA is precipitated on the surface of the tungsten or gold particle and shot into target cells is known as? 

  1. Microinjection

  2. Chemical - mediated genetic transformation

  3. Electroporation

  4. Biolistic method


Correct Option: A

Which one of the following is commonly used in transfer of foreign DNA into crop plants?

  1. Penicillium expansum

  2. Trichoderma harzianum

  3. Meloidogyne incognita

  4. Agrobacterium tumefaciens


Correct Option: D
Explanation:

Trichoderma harzianum is a biofungicide and is used for suppression of various disease causing fungal pathogens. Penicillium expansum, blue mold, causes postharvest decay of stored apples and produces the carcinogenic mycotoxin patulin. Meloidogyne incognita, southern root-knot nematode" or the "cotton root-knot nematode", is a nematode with multiple hosts. Agrobacterium tumefaciens is a soil plant pathogenic bacterium that carries Ti plasmid. It can transfer a particular segment of the tumor-inducing (Ti) plasmid into the nucleus of infected cells. The transferred T-DNA is then integrated into the host genome and transcribed with it. This ability of Agrobacterium tumefaciens to transfer the T-DNA in host genome is explored in genetic engineering to transfer the desired DNA segment, carrying the gene of the interest, into genome of selected organisms. Option D is the correct answer. 

Which one of the following is called polynucleotide joining enzyme?

  1. Polymerase I

  2. Polymerase II

  3. Ligase

  4. Ribonuclease


Correct Option: C
Explanation:

Ligase is nick named as 'molecular sutures'. In Biochemistry, ligase is defined as an enzyme that can catalyze the joining of two large molecules by forming a new chemical bond.

In retroviruses, RNA dependent DNA polymerase synthesizes

  1. DNA

  2. RNA

  3. RNA-DNA

  4. None of the above


Correct Option: C

Blood stain component to be used for DNA profiling technique is

  1. Serum

  2. Leucocytes

  3. Platelets

  4. Erythrocytes


Correct Option: B

Read the following four statements (A-D) about certain mistakes in two of them:

(A) The first transgenic buffalo, Rosie produced milk which was human alpha-lactalbumin enriched.
(B) Restriction enzymes are used in isolation of DNA from other macro-molecules.
(C) Downstream processing is one of the steps of r-DNA technology.
(D) Disarmed pathogen vectors are also used in transfer of r-DNA into the host.

Which are the two statements having mistakes?

  1. Statements (A) and (B)

  2. Statements (B) and (C)

  3. Statements (C) and (D)

  4. Statements (A) and (C)


Correct Option: A
Explanation:

(A) Rosie was the first transgenic cow and its milk was rich in human alpha-lactalbumin protein.

(B) Restriction enzymes are used in the isolation of the specific segment of DNA from the DNA of the organism because these enzymes are capable of cutting the DNA at the specific location.
(C) Downstream processing is one of the steps in the r-DNA technology. It involves the extraction and purification of the desired product.
(D) Disarmed pathogens like Agrobacterium tumifaciens, phage viruses are also used in the transfer of r-DNA into the host.
Hence, the correct answer is '(A) and (B)'