Q.No.

SECTION-A

Marks

1

The plants get benefits from mycorrhizal symbiotic association in the following ways:- (i) The fungal symbiont in mycorrhizal associations absorb phosphorus from soil and passes it to the plant.

(ii) It also provides resistance to root borne pathogens and increases plant growth and development.                                                                                                                         1+1

2

2

(a)      ‘Rosie’ was a transgenic cow. It was considered different from a normal cow as it produced human protein-enriched milk (alpha-lactalbumin 2.4 g/L).

(b)     (ά-1-antitrypsin) is used to treat emphysema.                                                                1+1

2

3

(i)             Introduction of Nile perch into Lake Victoria lead to extinction of more than 200 species of cichlid fish in that lake.

(ii)           Carrot grass (Parthenium and Lantana) introduced in our country have become invasive and cause environmental damage. They pose a threat to the native species of plants in our forests.                                                                                                                                   1+1

2

4

Edward Wilson

(a)    Species diversity

(b)   Genetic diversity

(c)    Ecological diversity                                                                                              ½+½+½+½ 

OR

(a) Cuscutahas lost its chlorophyll during evolution and developed haustoria through which it derives its nutrition from host plant. Thus, it is adapted as a parasitic plant. (b) Cattle avoid grazing on Calotropis plants because it produces poisonous cardiac glycosides.                                                        1+1

2      

5

(i)                 AIDS and hepatitis-B may occur. Because the viruses of these diseases are spread through sharing the infected needles and syringes.

(ii)               Due to regular use, tolerance of the receptors increases, so they respond only to higher doses of drugs leading to greater intake and addiction.                                                          1+1

2

6

Sample C is the most polluted one. 

Reason – BOD is a measure of the organic matter present in the water. The greater the BOD of waste water, more is its polluting potential.                                                                     1+1

OR

(a) Lactobacillus  (b) Trichoderma polysporum (c) Fungus (d) Penicillin               ½+½+½+½

2

SECTION-B

7

(a)  Preformed antibodies or antitoxin.

(b)  The injection provided the preformed antibodies that act on the pathogen immediately for quick immune response

(c)   Tetanus. Passive immunity                                                                                  1+1+½+½

OR

Mention the product and its use produced by each of the microbes listed below:-

(a)Streptococcus– Product is Streptokinase. It is used as a clot-buster for removing the clots from the blood vessels of patients suffering from myocardial infarction. 

3

(b)   Aspergillus niger– Product is Citric acid. It is used as a preservative and flavouring agent in food and beverages such as soft drinks. 

(c)   Saccharomyces cerevisiae– Product is Ethanol and also used for bread making and beverages                                                                      1+1+1

8

(a)           Bacillus thuringiensis

(b)           Cry proteins toxic to certain insects’ larvae and provide resistance against them. The gene coding Cry proteins are used in several crop plants like Bt cotton for resistance against particular insect pest like cotton bollworms.

(c)           ‘Cry’-Crystal protein; ‘cry’-Gene encoding Cry protein.                                     1+1+½+½

3

9

(a)    Polymerase Chain Reaction is used to amplify gene of interest.

(b)   These are specific base pair sequences of DNA, where restriction enzyme cuts the DNA

(c)    It is a technique, used to separate the DNA fragments according to their size through sieving effect of the gel.                                                                                             1+1+1

3

10

(i)Fungi:-They produce various kinds of thick-walled spores to survive under unfavorable conditions, which germinate on return of favorable conditions.

(ii) Zooplanktons:-They enter diapause, a stage of suspended development under unfavorable conditions.                                                                                                   1+1+1

(iii)Bears:-They hibernate during winter to escape the time of unfavourable conditions. 

3

       11   

(i)              Ori is the sequence of DNA from where replication starts (Origin of replication) and any piece of DNA, when linked to this sequence can be made to replicate within the host cells.

It is also responsible for controlling the copy number of linked DNA.

(ii)            amp^R is an antibiotic resistance gene in which ligation of alien DNA is carried out at a restriction site.

(iii)          rop codes for the proteins involved in the replication of the plasmid.                       1+1+1

3

12

(i)     A depicts conformers.

(ii)   The other line B depicts regulators.

(iii)  Regulator                                                                                                                    1+1+1

3

SECTION-C

13

(a)             Bio gas plant

(b)            A- Dung+Water,  B-Gas, C- Sludge  D- Digester  (c)Methanogens.

(d)   Mrthane,Hydrogen sulphide and Corbon di-oxide.

(e)    Gas for Coocking and lighting.                                          ½+½+½+½+½+½+½+½+½+½

OR

Rajiv was having recurrent fever with chills. He went to see the doctor and doctor diagnosed him with malaria.

(a)        Plasmodium vivax, Plasmodium malaria, Plasmodium falciparum   (Any two) 

(b)

(i)                   Female mosquito take up gametocytes with  blood  meal. 

(ii)                 Fertilization, takes place  mosquitoes  gut.

(iii)               Salivary gland, sporozoites.

(c)        Avoiding stagnation  of water, use of mosquito net  or any other valid point.

                                                             ½+½+½+½+½+½+½+½+½+½

5