CBSE Sample Question Papers for Class 12 Biotechnology 2020 PDF Download

CBSE Sample Question Papers for Class 12 Biotechnology 2020

Sample Question paper
CLASS- XII
BIO-TECHNOLOGY (045)
SESSION 2019-20

Time allowed: 3 hours                                                                           Maximum Marks: 70

General Instructions:

1. The question paper comprises four Sections – A, B, C and D. Attempt all the Sections.
2. All questions are compulsory.
3. There is no overall choice. However, an internal choice has been provided in five questions of one mark, three questions of two marks, three questions of three marks and three questions of five marks.
4. You have to attempt only one of the choices in such questions.
5. Questions paper contains four sections A, B, C and D.
6. Question numbers 1 to 7 are very short answer questions carrying 1 mark each.
7. Question numbers 8 to 12 are multiple choice questions carrying 1 mark each
8. Question numbers 13 to 19 are short answer questions, carrying 2 marks each.
9. Question numbers 20 to 26 are also short answer questions, carrying 3 marks each.
10. Question numbers 27 to 30 are long answer questions, carrying 5 marks each.
11. Use of calculators is not permitted. However, you may use log tables, if necessary.

SECTION A

Question 1.
Name any two scientists involved in designing the first recombinant DNA molecule.   [1]

Question 2.
Write any two properties which can be improved through protein engineering   [1]

Question 3.
Transgenic plants have been developed to survive in saline habitat. Which technique might have been used to develop such plants?   [1]

Question 4.
Which vector was used in the first cloning experiment involving mammalian cell?
OR
How does a modification enzyme protect its own DNA from digestion?   [1]

Question 5.
What was the strategy behind Human Genome Project?   [1]

Question 6.
An enriched medium containing salts, glucose, proteins and vitamins was made and a commercially available animal cell line was introduced. However, the cells began dying. What could be the reason behind it?   [1]
OR
What is A in the flow chart?

Question 7.
Margaret Dayhoff observed that protein sequences undergo variation according to certain patterns. Write any one such pattern.   [1]
OR
What is the underlying principle of “Molecular evolution”?

Question 8.
Crystallisation is not required due to the advent of which of the following new technique.   [1]
a) X-ray crystallography
b) NMR
c) Sanger’s method of protein sequencing
d) Edman’s method of protein sequencing

Question 9.
Optimum pH for plant tissue culture medium is –   [1]
a) 7.5
b) 5.7
c) 8
d) 8.5

Question 10.
The single letter codes for Tyrosine and Asparagine are   [1]
a) N and Y
b) A and T
c) T and A
d) Y and N

Question 11.
The disease due to the deficiency of an enzyme Adenosine Deaminase (ADA) is   [1]
a) SCID
b) Thallasemia
c) Haemophilia
d) Mad cow disease

Question 12.
Question numbers 12(i) to 12(iv) are based on the following text on characterization of Cell Lines:
In order to analyze the growth characteristics of a particular cell type or cell line, a growth curve can be established from which one can obtain a population doubling time, a lag time, and a saturation density. A growth curve generally will show the cell population’s lag phase, that is, the time it takes for the cells to recover from subculture, attach, and spread; the log phase, in which the cell number begins to increase exponentially and a plateau phase, in which the growth rate slows or stops due to depletion of growth factors and nutrients.

(i) Beyond what cell concentration , saturation density is achieved?   [1]
a) > 10⁴ cells /ml
b) 10⁴ to 10⁵ cells /ml
c) > 10⁵ cells /ml
d) > 10⁶ cells /ml

(ii) There is no increase in the cell concentration in the lag phase due to the following reasons:   [1]
a) Exhaustion of the medium.
b) Space constraint
c) Both “a” and “b”
d) Acclimatization to the new environment.

(iii) . In which phase of growth is the specific growth rate of animal cell calculated?   [1]
a) Log phase
b) Lag phase
c) Stationary phase
d) Decline phase.

(iv) A student adds antibiotic to the animal cell culture medium and still obtains the 1 same growth curve .The probable explanation for it will be:   [1]
a) Antibiotics add growth factors and hormones in the medium
b) Antibiotics provide serum for the growth of animal cells.
c) Antibiotics enhance the nutrient content of the medium.
d) Antibiotics don’t have any affect on animal cells

SECTION B

Question 13.
Differentiate between synthetic and complex medium used for microbial culture.   [2]

Question 14.
How can LEU 2 gene be used as a selectable marker?   [2]

Question 15.
On the basis of the table given below, state your observations pertaining to the organisation features of the organism.   [2]

Question 16.
Differentiate between somaclones and gametoclones. Who proposed the term somaclones?   [2]

Question 17.
a) What are the various interactions that stabilize a folded protein?   [2]
b) How can the stability of protein be changed?

Question 18.
What are various biosafety issues in microbial technology?   [2]
OR
The laboratory scale design cannot be scaled up to industrial scale directly. Write any two points that need to be considered while going for industrial scale production.

Question 19.
In a variant of chymotrypsin, Asp 102 is replaced by Glu 102. Do you expect the enzyme to retain activity Schematically indicate the role of amino acid residues participating in catalysis.   [2]
OR
Thalassemic patients produce excess alpha or beta subunits of haemoglobin leading to impaired oxygen-binding capacity by their erythrocytes. How can it be determined as to which subunit is produced in excess?

SECTION C

Question 20.
Recombinant insulin is produced at 100 mg/l by E. coli at a cell concentration of g/l. Calculate the volume of reactor (size of the fermentor) needed to produce kilogram of insulin in the following conditions:   [3]
(a) When the cell concentration is 1 g/l and insulin production is 100 mg /l.
(b) When the cell concentration is 50 g/l and insulin production is 100 mg /l.
(c) When the cell concentration is 50 g/l and insulin production is 500 mg /l

Question 21.
Schematically explain the formation of recombinant plasmid.   [3]
OR
Students of Class XII visited Microbial Type Culture Collection, Chandigarh and observed microbial cultures of Providencia stuartii, Streptomyces albus and Haemophilus aegyptus. Name the restriction enzymes obtained from them and also specify their restriction sites.

Question 22.
Complete the table by filling the mode of action / functional properties indicated as A, B, C, D, E and F   [3]

Question 23.
Selection is an important step in genetic engineering. You are given ampicillin and tetracycline antibiotics. Using these antibiotics, which selection technique could be used to differentiate between recombinant and non-recombinant cells?   [3]

Question 24.
Write any six applications of plant genetic engineering.   [3]

Question 25.
How does the metagenomics approach help to identify novel genes present in the environment? Explain the process.   [3]
OR
What is a pilot plant? Why is it necessary to validate a process in a pilot plant before commercial scale production in a bioprocess industry?

Question 26.
Given below are few transgenic crops approved by US food and drug administration along with the improved character. Name the genes A to F introduced for the improved character.   [3]

SECTION D

Question 27.
Mutation is an alteration in any of the base of a DNA sequence sometimes leading to a defective protein or prematurely terminated non-functional protein. It can be spontaneous or induced. Diagrammatically explain how mutation can be induced in a gene.   [5]
OR
A bacteriophage is known to infect E.coli with pili. How can it be modified to serve as a suitable vector?
What are the major advantages of developing vectors based on such bacteriophages?

Question 28.
Explain the non-covalent interactions involved in organizing the structure of protein molecules.   [5]

Question 29.
Which two main methodologies are used for genome sequencing? Explain.   [5]
OR
Explain the diseases caused by single gene mutations following mendelian inheritance specifying the genomic location, inheritance pattern and mutation. Name any two diseases showing gene polymorphism with complex inheritance.

Question 30.
Diagrammatically show the cultivation of adult stem cells from bone marrow and their differentiation into specialized cells. Name two scientists who established the field of stem cell research. For which medical conditions, stem cells can be used (Write any two)?   [5]