CBSE(NCERT) GRADE 12 BIOTECHNOLOGY 2023 COMPARTMENT SET1

To obtain a virus-free plant, what can be used as an explant in micropropagation ?

Large-scale characterization of entire protein complement of cell is :

The genetically modified brinjal has been developed for :

Which of the following proteins will you expect to run the fastest through SDS-PAGE gel ?

The Nucleotide sequence in both the DNA strands reads the same in 5' to 3' directions:

Whey protein forms and stabilizes fat emulsions because of which one of the following functional properties?

The most common type of restriction enzyme used in recombinant DNA technology are:

The lack of a particular subunit or of the oxygen carrying protein haemoglobin results in:

Which primer can be used to amplify the following strand of DNA? $5'\,ATTCGTGTACTGCAT\,3'$

When 2 copies of dsDNA molecules are added to PCR, how many copies of dsDNA will be formed after completion of 3 cycles?

Assertion (A): Diet of athletes should have more eggs and meat as compared to other sources of protein like whey and soya milk. Reason (R): Eggs and meat are richer sources of BCAA.

Assertion (A): Baffle flask is used in laboratories for microbial cell culture. Reason (R): Baffle flask improves the efficiency of oxygen transfer due to increased turbulence of the agitated culture medium.

Assertion (A): In mass spectrometric analysis, protein molecules can be separated on the basis of $m/z$ ratio. Reason (R): Gas-phase charged molecular ions are generated by MALDI.

Assertion (A): Analysis of mRNA does not provide a direct reflection of the protein content in the cell. Reason (R): mRNA and protein expression level do not always correlate.

Why is inverted microscope used in place of compound microscope while observing animal cells in culture?

What are the constraints associated with public acceptance of transgenic crops?

Annotation of human genome sequence reveals that our genome contains 30,000 33,000 genes. Proteomic analysis indicates that human cells are capable of synthesizing more than 30,000 different proteins. How can this discrepancy be reconciled?

(a) What are the various interactions that stabilize a folded protein? (b) How can the stability of a protein be changed?

(a) What are stem cells? (b) For which medical conditions can stem cells be used? Mention any two.

(a) (i) Curd and whey are categorised as nutraceutical proteins. Why? (ii) Give an example of novel recombinant vaccine developed by India.

Suggest a recombinant strategy for the following traits in transgenic crops: (a) Delayed fruit ripening (b) Increased resistance to nematodes (c) Rejection of alien pollen.

Suggest a genetic engineering strategy for each of the following traits in transgenic crops: (a) Delayed ripening (b) Pest resistance (c) Abiotic stress tolerance

Make a schematic diagram and show how ES cells can be used for making Chimeric mouse.

What is ES Cell culture? Mention its four advantages.

sequences using this tool.

Name three enzymes used in cloning and write one function of each.

The microarray technique can be used to compare gene products between normal and cancer cells. Explain the technique.

The technique of DNA fingerprinting is very much in the news these days. Why? Highlight its principle.

Enzyme chymotrypsin is synthesised in the pancreas and through the pancreatic duct released into the duodenum. The enzyme is made up of a linear chain of 245 amino acids interrupted into three peptides A, B, C. The protein folds into a globular structure. Chymotrypsin is synthesised as inactive harmless precursors known as Zymogens which are then activated when required, only in the duodenum. (a) Name the two protein molecules that have a reactive serine residue which is central to the catalytic mechanism. 1 (b) Chymotrypsin allows bulky aromatic hydrophobic amino acid to bind. Justify. 1 (c) What is In-situ activation of Chymotrypsinogen? 2 OR (c) Explain the mode of action of Chymotrypsin. 2

Continuous culture is a continuous process where nutrients are continually added to the bioreactor and the culture broth is removed at the same time. The volume of the culture is constant due to a constant feed-in and feed-out rate. In continuous culture, parameters such as pH, oxygen, the concentration of excretion products and population densities can easily be monitored and controlled. (a) What do you mean by steady state? 1 (b) What is continuous culture used for? 1 (c) In continuous culture, cells can be grown at a particular __________ for an __________ period of time. 2 OR

Continuous culture is a continuous process where nutrients are continually added to the bioreactor and the culture broth is removed at the same time. The volume of the culture is constant due to a constant feed-in and feed-out rate. In continuous culture, parameters such as pH, oxygen, the concentration of excretion products and population densities can easily be monitored and controlled. (c) For a continuous culture, draw a graph to illustrate the variation of cell density $[X]$, concentration of substrate $[S]$ and the cell specific substrate turnover rate $[Q_S]$ with time.

(a) (i) An enriched medium containing glucose, peptone, salts and vitamins was made and a commercially available animal cell line was introduced. However, the cells began dying. What could be the reason for this? (ii) Why is r-HuEPO preferred over blood transfusion in a person with blood loss due to an accident? (iii) While growing animal cells in a laboratory, osmolality of a medium is always maintained around 300 m OSM. Why?

(a) How is the blue-white selection method used to screen the transformed host cells? Describe any two methods of introducing recombinant DNA into host cells.

(a) (i) Illustrate any two methods of measuring microbial growth. (ii) In which phase of growth is the specific growth rate of microbial cells calculated? (iii) Calculate the doubling time of a bacterial population in which the number of bacteria increases from $10^4$/mL to $10^7$/mL during three hours of exponential growth.

(b) (i) With the help of a suitable example, explain the nomenclature of restriction enzyme. (ii) e in phage ? (iii) How can LEU2 gene be used as a selectable marker?