Biology Sample Question Paper for Class 12

Sample Question Paper - 1

PRE-BOARD EXAMINATION TERM-II (2021-22) 

CLASS-XII

BIOLOGY (044)

Max.Marks:-35                                                                                                                         Time Allowed:-2 Hours

General Instructions:-

(i)              All questions are compulsory.

(ii)            The question paper has three Sections and 13questions. All questions are compulsory.

(iii)          Section-A has 6 questions of 2 marks each; Section-B has 6 questions of 3 marks  each; and Section-C has a case-based question of 5 marks.

(iv)          There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.

(v)            Wherever necessary, neat and properly labelled diagrams should be drawn.

Q.No.

SECTION-A

Marks

1

How do plant benefit from having mycorrhizal symbiotic association?

2

2

(a)How ‘Rosie’ is considered different from a normal cow? (b)Name the protein used for treatment of emphysema.

2

3

Sometimes alien species affect the indigenous organisms leading to their extinction. Substantiate this statement with the help of any two examples.

2

4

Name the Sociobiologist who popularized the term Biodiversity. Identify the levels of biodiversity in India represented by:-

(a)    Diversity among Amphibian in Eastern and Western Ghats.

(b)   50,000 strains of Rice in India.

(c)    Presence of Deserts, Mangroves and Coral reefs of India.     

OR

(a)   How is Cuscuta adapted to be a parasitic plant?

(b)  Why do cattle avoid grazing on Calotropis plants?

2

5

Due to undue peer pressure, a group of adolescents started using opioids intra-venously. What are the serious problems they might face in future?

        2

6

The BOD values of the three samples A, B and C collected from different areas were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? State the reason of your answer.

OR

Name the blank spaces a, b, c and d in the following table:-

2

 

Type of microbe

Name

Commercial product

  

Bacterium

a

Lactic acid

 

Fungus

b

Cyclosporin A

 

c

Monascuspurpureus

Statins

 

Fungus

Penicillium notatum

d

 

SECTION-B

 

7

A heavily bleeding and bruised road accident victim was brought to a nursing home. The doctor immediately gave him an injection to protect him against a deadly disease.

(a)           Write what the doctor injected into the patient’s body.

(b)           How do you think this injection would protect the patient against the disease?

(c)            Name the disease against which this injection was given and the kind of immunity it provides.

3

 

OR

Mention the product and its use produced by each of the microbes listed below:-(a)Streptococcus

(b)   Aspergillus niger

(c)    Saccharomyces cerevisiae

8

(a) Give the name of the soil bacterium which produces crystal (Cry) proteins. (b) How are these proteins useful in agriculture?

(c) What do the differently written terms ’Cry’ and ‘cry’ represent respectively.

9

How are the following used in Biotechnology?

(a)    PCR

(b)   Recognition Sequence

(c)    Gel electrophoresis

10

How do organisms like fungi, zooplanktons and bears overcome the temporary short-lived climatic stressful conditions? Explain.

 

3

3

3

11

Explain the importance of (i) ori, (ii) ampR and (iii) rop in the E. coli vector shown below:-

3

 

12

The following graph represents the organismic response to certain environmental condition

(e.g. Temperature)

(i)                 Which one of these A or B depicts conformers?

(ii)               What does the other line of graph depict?

(iii)             Mention the category to which humans belong.

3

 

SECTION-C

 

13

 A farmer has made following  structure in front of his house.

Observe the  given below structure and answer the following questions:-

(a) Write the name of the structure given in above picture.

(b) Label the parts A,B,C and D.

(c) Name the bacteria responsible fir the production of biogas.

(d) What is the composition of biogas?

(e) What benefit farmer will get from the structure?

OR

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

(a) Name any two species of Plasmodium that cause malaria.

(b) Study a part of the life cycle of Malarial parasite given below and answer the questions that follow:

(i) Mention the roles of ‘A’ in the life cycle of the malarial parasite.

(ii) Name the event ‘C’ and the organ where this event occurs.

(iii) Identify the organ ‘B’ and name the cells being protected from it.

(c) State any two ways by which a person can be protected from getting malaria.

5

  

Marking Scheme

PRE-BOARD EXAMINATION TERM-II (2021-22)

CLASS-XII

BIOLOGY (044)

MARKING SCHEME OF QUESTION PAPER  

Max. Marks:-35                                                                `                                                         Time Allowed:-2Hours

General Instructions:-

(i)              Answers given in this marking scheme are indicative.

(ii)            Full marks to be given if student has conveyed the value points.

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)            ampR 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

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I just like the helpful information you provide in your articles

I just like the helpful information you provide in your articles

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