Tag: botany

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Questions Related to botany

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

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
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The product produced by the bacteria that digests the antibiotic (like ampicillin) is a protein (an enzyme like beta-lactamase). In the context of recombinant DNA technology, this is a recombinant protein product.

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

The correct sequence of making a cell competent is

  1. Treatment with divalent cations incubation of cells with recombinant DNA on ice heat shock ($42^0$C) placing on ice
  2. Heat shock ($42^0$C) incubation of cells with recombinant DNA on ice treatment with divalent cations placing on ice
  3. Treatment with divalent cations placing on ice incubation of cells with recombinant DNA on ice heat shock ($42^0$C)
  4. Incubation of cells with recombinant DNA on ice heat shock ($42^0$C) treatment with divalent cations placing on ice
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In order to force a bacteria to take up the plasmid , the bacterial cells must to be made competent. This is done by treating them with a specific concentration of divalent cations such as calcium which increases the efficiency with which the DNA molecule enters into the bacteria through pores in its cell wall. Recombinant DNA then forced into such cells by incubating the cells with recombinant DNA on ice followed by placing them immediately at heat shock and then again into ice. This enables the bacteria to take up the recombinant DNA. 

So, the correct option is 'Option A' .

Multiple choice botany biotechnology: principles and processes dna transfer rdna technology - dna transfer and transformation gene cloning procedure biotechnology in agriculture

Statement 1 : In insertional inactivation, blue colour produced by bacterial colonies indicates that the plasmid does not have an insert into the bacterial genome. 
Statement 2: Presence of insert results into insertional inactivation of -galactosidase enzyme and the colonies do not produce any colour.

  1. Both statements 1 and 2 are correct

  2. Statement 1 is correct but statement 2 is incorrect

  3. Statement 1 is incorrect but statement 2 is correct

  4. Both statements 1 and 2 are incorrect
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Selectable markers have been developed which differentiate recombinants from non- recombinants on the basis of their ability to produce colour in the presence of a chromogenic substrate. In this, a recombinant DNA is inserted within the coding sequence of an enzyme B-galactosidase. This results into an  insertional inactivation. The presence of chromogenic substrate gives blue coloured colonies if the plasmid in bacteria does not have an insert. Presence of insert results into insertional inactivation of a^-galactosidase enzyme and the colonies do not produce any colour, these are identified as recombinant colonies. 

So, the correct option is 'Option A' .

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

rDNA is

  1. Genomic RNA of virus

  2. Genomic RNA that produces DNA through reverse transcription

  3. DNA found in ribosome

  4. DNA segment speciaiised to form rRNA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ribosomal DNA (rDNA) is a DNA sequence that codes for ribosomal RNA. Ribosomes are assemblies of proteins and rRNA molecules that translate mRNA molecules to produce proteins. In the nucleus, the rDNA region of the chromosome is visualized as a nucleolus which forms expanded chromosomal loops with rDNA.

So, the correct answer is 'DNA segment speciaiised to form rRNA.'

Multiple choice botany biotechnology: principles and processes dna transfer rdna technology - dna transfer and transformation gene cloning procedure biotechnology in agriculture

Direct visual selection method for the selection of recombinant host cells on the basis of their inability to produce colour in the presence of chromogenic substrate can be applied if the vector used is a

  1. Modified plasmid vector of E.coli

  2. Modified bacteriophage

  3. Modified Agrobacterium tumifaciens plasmid

  4. Disarmed retroviruse
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The blue-white screening method uses a modified plasmid vector (like pUC19) in E. coli to detect recombinants based on the inactivation of the lacZ gene, which produces a color change.

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

Chimeric DNA is

  1. Gene clone

  2. Recombinant - DNA

  3. Transposon

  4. Vector shuttle
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Recombinant DNA molecules are sometimes called chimeric DNA, because they can be made of material from two different species, like the mythical chimera.
  • A chimera is essentially a single organism that is made up of cells from two or more individuals—that is, it contains two sets of DNA, with the code to make two separate organisms.
  •  R-DNA technology uses palindromic sequences and leads to the production of sticky and blunt ends.
So, the correct answer is 'Recombinant - DNA'.

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

Two bacteria found to be very useful in genetic engineering experiment are

  1. Nitrosomonas and Klebsiella

  2. Escherichia and Agrobacterium

  3. Nitrobacter and Azotobacter

  4. Rhizobium and Diplococcus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Till today, the most important in genetic engineering of plants has been the Ti plasmid of soil bacterium, Agrobacterium tumefaciens. E.Coli  has been extensively used as "work horse" for genetic engineering e.g., production of humulin, somatotropin. E. coli is one of the most thoroughly studied of all living things. It is a favorite organism for genetic engineering as cultures of it can be made to produce unlimited quantities of the product of an introduced gene. Several important drugs (insulin, for example) are now manufactured in E. coli. Thus, option B is correct. Nitrosomonas, Klebsiella, Nitrobacter, Azotobacter, Rhizobium and Diplococcus are not used in genetic engineering.

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

Which of the following most used in genetic engineering?

  1. E.coil and Agrobacterium

  2. Mycobacteria and Salmonella

  3. Aspergillus

  4. Penicillium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Genetic engineering is a branch of science that uses various biotechnological techniques to manipulate an organism's genome to  create species with desired traits. However, the process involves isolation, transfer and insertion of the new genetic material into host genomes and storage of genomes in organisms and selective markers for an indefinite period. Experiments have shown that certain bacteria has the ability to naturally take in and express foreign DNA.  It has been found that of these,  E.coli  has the ability to transfer DNA laterally to and from other species while Agrobacterium  can transfer genes to plants and fungi by causing crown gall disease.

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

Two bacteria most useful in genetic engineering are

  1. Rhizobium and Azotobacter

  2. Escherichia and Agrobacterium

  3. Rhizobium and Diplococcus

  4. Nitrosomonas and Klebsiella
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Escherichia coli and Agrobacterium tumefaciens are the most widely used bacteria in genetic engineering for cloning and plant transformation, respectively.

Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

Competent host in recombinant DNA technology is __________________.

  1. Any human cancer cell

  2. The cell ready to update align DNA

  3. A host cell without cell wall

  4. Agrobacterium cell
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Option 'D' is correct.


Competent host is recombinant DNA technology is Agrobacterium cell. Competent host cell is required for transformation with recombinant DNA. Different types of available host cells are like E.cola, yeast, animal and plant cells. Eukaryotic cells will be preferred host, yeast-cells are preferred because this are simple eukaryotic organism and like bacteria are single-celles, easy to grow manipulated. Bacteria also acts enabled to pick up the recombinant-DNA.