(Download) CBSE Class-12 Sample Paper 2018-19 :
Time allowed: 3 Hours
Max. Marks: 70
(i) Question paper contains four sections-A, B, C and D.
(ii) All questions are compulsory
(iii) There is internal choice in all sections. You have to attempt only
one of the choices in such questions.
(iv) Question numbers 1 to 6 are very short answer questions, carrying 1
(v) Question numbers 7 to 14 are short answer questions, carrying 2 marks
(vi) Question numbers 15 to 25 are also short answer questions, carrying 3
(vi) Question numbers 26 to 28 are long answer questions, carrying 5 marks
(vii) Use of calculators is not permitted. However, you may use log
tables, if necessary.
1. 4 copies of ds DNA are subjected to polymerase chain reaction. How many
copies would be
obtained after 20 cycles?
1.How can we use LEU 2 gene as a selectable marker?
2. Specify the role of alkaline phosphatase in cloning.
3. Specific activity increases during subsequent steps of a protein
purification scheme. How can you relate it with the purity of protein?
4. Animal cells in a culture medium were placed in a regular incubator used
for growing bacterial
cells. Do you expect the animal cells to grow or not?
5. What is Gene Knock out?
6. What will be the consequence if a protein is having an altered structure?
6.Expand and define PER?