Class-12
Paper-Biology M.M-70.
General Instructions
1. This paper is divided into four sections A, B,C, D answer all questions...
2. Section-A consist of one question having sub-parts of one mark / two marks each.
3. Section-B consists of seven questions of two marks each.
4. Section-C consists of three questions of three marks each.
5. Section D - consist of three questions of fine marks each.
6. Internal choices have been provided in one question each in Section B, Section C and
Section A
7. The intended marks for questions or parts of questions are given in brackets [ ].
Section A (20 marks)
(i) How do interferons protect us? (1)
(ii) Why do normal red blood cells becomes elongated and sickle shaped in structure in
a person suffering from sickle cell anaemia? (1)
(iii) BOD of two samples of water A and B were 120 mg/l and 400 mg/ l respectively.
which is more polluted. (1)
(iv) Based on the table given below. Identify the name of antibody
% in blood Function
75-80% Responsible for RH factor in blood (1)
(v) Match the column I and II with reference micro-organisms and organic acid
produced by them. Choose the correct option from the choices given below.
Organic acids Micro organisms
1. Citric Acid (p) Colostridium butyricum
2. Butyric Acid (q) Aspergillus niger
3. Acetic Acid (r) Acetobacter acetii
4. Lactic Acid (s) Trichoderma polysporum
(a) 1-(p) 2-(q) 3-(r) 4-(s)
(b) 1-(r) 2-(p) 3- (q) 4-(s)
(c) 1-(p) 2-(r) 3-(q) 4-(s)
(d) 1-(q) 2-(r) 3-(s) 4-(p) (1)
(vi) Assertion - In Sickle cell anaemia, the codon GAG is replaced by GUG
Reason: The gene for the above mutation occurs on the Y- chromosome
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of the A
(c) A is true but R is false
(d) A is false, but R is true (1)
(vii) Assertion: hCG hormone is released by the Placenta
Reason: It stimulates corpus luteum to secrete progesterone
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true (1)
(viii) The diagram given below shows the structure of human male gamete or Sperm
Mention the Role played by the part labelled as 'X' (1)
(ix)The mutation theory of evolution states that the evolution occurs by the sudden
large differences in the population. Name the scientist who proposed this theory (1)
(x) A vaccination provides a category of adaptive immunity. Name It (1)
(xi) Give one significant contribution of oparin and Haldane (1)
(xii) The correct sequence of hormones secreted from beginning to the end of
menstrual cycle is
(a) FSH, progesterone, and LH
(b) Oestrogen, FSH and progesterone
(c) FSH, Oestrogen, progesterone
(d) Oestrogen, progesterone, FSH. (1)
(xiii) Human evolution is evolutionary process which was not linear, but web like.
OR
Mention any one aspect that made the Ramapithecus differ from the Dryopithecus (1)
(xiv) Give reasons for the following.
(a) Both wind and water pollinated flowers are not very colourful and do not produce
nectar.
(b) The absence of menstrual cycle during pregnancy (2)
(xv) Sertoli cells are elongated and pyramidal that provides attaching site to the
spermatogenic cells. State the function performed by Sertoli cells (1)
(xvi) Expand the abbreviation ELISA (1)
(xvii) Name the Scientist who discovered the term Vaccine (1)
(xviii) What conclusions are drawn by Urey and miller experiments (2)
Section B (14 marks)
Q2: During botany lecture, teacher explained that an embryo sac contains 8 nucleus but
It is 7-celled structure.
(i) Name the structure found at the micropylar and chalazal end of the embryo sacer
(ii) Mention the function of filliform apparatus (2)
Q3: A biological class teacher carried out a cross between two pea plants showing
contrasting ring traits of height of the plants The result of the cross showed 50%
parental characters
(i) Work out the cross on the observations discussed above with the help of Punett
Square
(ii) Name the type of cross carried out in part (i) (2)
Q4: Given below is a picture of typical biogas plant. Observe it carefully and answer the
questions.
(a) Identify and write the names of parts A & B & C
(b) What are methanogens used in biogas plant. (2)
Q5: Give one difference between the following pairs
(i) ZIFT and IUT
(ii) Benign tumour and malignant tumour. (2)
Q6: Write the Scientific me of the cousitive Name agent and mode of transmission of
each of the following diseases.
(i) Dengue fever
(ii) Common cold. (2)
Q7: Draw a neat and well labelled diagram of TS of an anther (2)
Q8: Study the figure the questions that follows below and answer
(i) Identify the part labelled as A and name the stage of human embryo in the figure
represent
(ii) Give any two differences between implantation and Contraception
OR
Draw a neat labelled diagram of menstrual cycle in females showing all phases.(2)
Section C (21 Marks)
Q9: Explain Lederberg culture plate experiment in detail. (3)
Q10: what is Natural selection? Give its types. (3)
Q11: Draw a neat and well-labelled diagram of an anatropous Ovule.
OR
Draw a neat and well labelled diagram of structure of ovum. (3)
Q12: list two infectious diseases (Bacterial/virus)
(i) Mention their Causitive organism
(ii) Give their preventive measures? (3)
Q13: (i) What do you mean by the phenomenon of adaptive radiation?
(ii) How marsupial radiation in Australia sets an example of adaptive radiation (3)
Q14: What are Mutations & Discuss its types
OR
What is crossing over? How it occurs (3)
Q15: what are Allergens? what is the relationship between Allergens & Antibodies. (3)
Section D (15 Marks)
Q16: Study a part of life cycle of malarial parasite given below. Answer the questions
that follows. (5)
(a) Mention the role of A in the life cycle of malarial parasite.
(b) Name the event C and the organ where this event occurs.
(c) How malaria can be prevented
OR
(a) What are false fruits? give an example
(b) what is meant by parthenocarpy? Name the fruit develops by this method.
Q17: Answer the questions based on the Diagram shown below
(i) Identify the plant shown in above diagram. What drugs can be obtained from this
plant.
(ii) What are the modes of Consumption of these drugs. (5)
Q18: (a) Cancer is one of the most dreadful disease. Explain 'Contact Inhibition' and
'metastases' with respect to disease.
(b) Name any two techniques that are useful in detecting cancers.
(c) what are proto oncogenes ? How are they different from oncogens.
(d) How cancer is caused. (5)
