Subject

Biology

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
Advertisement

 Multiple Choice QuestionsShort Answer Type

11.

(a) Can a plant flowering in Mumbai be pollinated by pollen grains of the same species growing in New Delhi ? Provide explanations to your answer.

2130 Views

12.

Both Haemophilia and Thalassemia are blood related disorders in humans. Write their causes and the difference between the two. Name the category of genetic disorder they both come under.

1123 Views

13.

(a) List the two methodologies which were involved in human genome project. Mention how they were used.
(b) Expand ‘YAC’ and mention what was it used for.

1515 Views

14.

Write the characteristics of Ramapithecus, Dryopithecus and Neanderthal man.

1421 Views

Advertisement
15.

Name a human disease, its causal organism, symptoms (any three) and vector, spread by intake of water and food contaminated by human faecal matter.

692 Views

16.

(a) Write the desirable characters a farmer looks for in his sugarcane crop. (b) How did plant breeding techniques help north Indian farmers to develop cane with desired characters ?

849 Views

17.

Secondary treatment of the sewage is also called Biological treatment. Justify this statement and explain the process

717 Views

18.

(a) Explain the significance of palindromic nucleotide sequence in the formation of recombinant DNA.
(b) Write the use of restriction endonuclease in the above process.

1317 Views

Advertisement
Advertisement

19.

Describe the roles of heat, primers and the bacterium Thermus aquaticus in the process of PCR.


Role of Heat : - It helps in denaturation process in PCR. The ds DNA is heated in this process at very high temperature (95ºC) so that both the strands separates. Role of primers : - Primers are chemically synthesised small oligonucleotides of about 10-18 nucleotides that are complementary to a region of template DNA and helps in the extension of new chain. Role of Bacterium Thermus aquaticus : - From this bacterium, a thermostable Taq DNA polymerase is isolated which can tolerate high temperatures and forms new strand.

875 Views

Advertisement
20.

Explain the various steps involved in the production of artificial insulin.

903 Views

Advertisement