Biotechnology Principles and Processes

Previous Years' CBSE Board Questions

9.1 Principles of Biotechnology

MCQ

In biotechnology experiments, 'molecular scissors' used are

1. plasmid (b) restriction enzymes
2. vectors (d) sigma factor.

(Foreign 2014)

(2020C)

V5A (1 mark)

What is the cell that receives a recombinant gene called? (AI 2019)

1. Write the two components of the first artificial recombinant DNA molecule constructed by Cohen and Boyer. (Foreign 2014)

9.2 Tools of Recombinant DNA Technology

MCQ

(2020) 🕕

(Delhi 2019)

4 Given below is the restriction site of a restriction endonuclease Pst-I and the cleavage sites on a DNA molecule. 5'C-T-G-C-A±G3' 3' G * A - C - G - T - C' 5' Choose the option that gives the correct resultant fragments by the action of the enzyme Pst-I.

1. 5'C-T-G C-A-G3' 3' G - A - C - G - T C 5'
2. 5'C-T G-C-A-G3' 3' G - A - G - C T - C 5'
3. 5'C-T-G-C A - G 3' 3' G - A - C - G T - C 5'
4. 5'C-T-G-C-A G 3' 3' G A-C-G-T-C5' (2023) Ap

1. Introduction of an alien DNA into a plant host cell is achieved by making them
2. competent with bivalent ions
3. using microinjections
4. using gene gun
5. using lysozymes and chitinase.

VSA (1 mark)

1. A host cell must be made competent, before it is able to receive an rDNA. Justify.

Suggest a technique to a researcher who needs to

separate fragments of DNA. (Delhi 2016) Ev

1. Mention the type of host cells suitable for the gene gun to introduce an alien DNA. (Delhi 2014)
2. Name the host cells in which microinjection technique is used to introduce an alien DNA.
3. Name the material used as matrix in gel-electrop- horesis and mention its role. (AI 2014C) R

SAI (2 marks)

1. 'Insertional inactivation' is a method to detect recombinant DNA. Explain the method. (2023) R
2. How does EcoRI specifically act on DNA molecule? Explain. (2020)
3. Write the basis of naming the restriction endonuclease EcoRI. (2020) []
4. All cloning vectors do have a 'selectable marker'. Describe its role in recombinant DNA technology.

β-galactosidase enzyme is considered a better

selectable marker. Justify the statement.

Explain the principle that helps in separation of DNA

fragments in Gel electrophoresis. (2019C)

17. What is EcoRI? How does EcoRI differ from an

exonuclease? (Delhi 2015C) U

State how has Agrobacterium tumefaciens been made

a useful cloning vector to transfer DNA to plant cells.

(Delhi 2014)

How are 'sticky ends' formed on a DNA strand? Why

are they so called? (Delhi 2014)

Write the role of ori and 'restriction' site in a cloning

vector pBR322. (Delhi 2014) R

How does a restriction nuclease function? Explain.

(Al 2014)

1. How is insertional inactivation of an enzyme used as a selectable marker to differentiate recombinants from non-recombinants? (Foreign 2014)
2. Explain palindromic nucleotide sequence with the help of a suitable example. (Foreign 2014) R

Why is making cells competent essential for

biotechnology experiments? List any two ways by

which this can be achieved. (AI 2014C)

(1/3 Term II, 2021-22) [1]

SAII (3 marks) Clal < / HindIII

EcoRI

PvuI BamHI

1. Given below is the stepwise schematic representation of the process of electrophoresis. Identify the 'alphabets' representing (i) Anode end (ii) smallest/lightest DNA strand in the matrix (iii) Agarose gel

Pst1 <math>amp^R</math> pBR322

R Sall 4 end 3 end PvuII

0 2 (S)

1 11 11

T (2020) U

1. What is elution? State the importance of elution in this process. (Term II, 2021-22)

Non-viral and non-vector methods are sometimes used to transfer genes or alien DNA into a plant cell. Explain one such method used in genetic engineering. (Term II, 2021-22) [EV]

(AI 2019)

Name any two natural cloning vectors. Give reasons that make them act as cloning vectors. Write the two characteristics the engineered vectors are made to possess. (2020)

1. Write the palindromic nucleotide sequence EcoRI recognises.
2. Draw the vector DNA and a foreign DNA showing the sites where EcoRI has acted to form the sticky ends.
3. (a) Explain the significance of 'palindromic nucleotide sequence' in the formation of recombinant DNA.
4. Name the enzymes that help in forming recombinant DNA. (2020)
5. Given below is the diagram representing the observations made for separating DNA fragments by gel electrophoresis technique. Observe the illustration and answer the questions that follow:

DNA bands Wells Largest Smallest (Al 2016) -

1. Why are the DNA fragments seen to be moving in the direction <math>A \rightarrow B</math>?
2. Write the medium used in which DNA fragments separate.
3. Mention how the separated DNA fragments can be visualised for further technical use.

(2020) Ap

Observe the diagram shown below of pBR322. Answer the questions that follow:

1. What is pBR322?
2. Write the role of 'rop'.
3. State the significance of amp^R and tet^R.
4. Describe the formation of recombinant DNA by the action of EcoRI. (Delhi 2019)

How does β-galactosidase coding sequence act as a

selectable marker? Why is it a preferred selectable

marker to antibiotic resistance genes? Explain.

Explain the roles of the following with the help of an

example each, in recombinant DNA technology:

(a) Restriction enzymes

1. Plasmids (2018)

Explain the roles of the following in biotechnology:

(a) Restriction endonuclease

1. (c) Selectable markers in pBR322. (Delhi 2017)

1. Write the use of restriction endonuclease in the above process. (Al 2017) An
2. Name the selectable markers in the cloning vector pBR322. Mention the role they play.
3. Why is the coding sequence of an enzyme β-galactosidase a preferred selectable marker in comparison to the ones named above?
4. (a) Why must a cell be made 'competent' in biotechnology experiments? How does calcium ion help in doing so?
5. State the role of 'biolistic gun' in biotechnology experiments. (AI 2016)
6. Name and describe the technique that helps in separating the DNA fragments formed by the use of restriction endonuclease.

(Foreign 2015, AI 2014) (U

State the functions of the following in the cloning

vector pBR322:

1. ori, (b) rop, and
2. HindIII sites (AI 2015C) R