BIOLOGY SAMPLE PAPER (044)

CLASS : XII

General Instructions:

(i) All questions are compulsory.

(ii) The question paper has five sections and 33 questions. All questions are compulsory.

(iii) Section-A has 16 questions of 1 mark each; Section-B has 5 questions of 2 marks each; Section- C has 7questions of 3 marks each; Section- D has 2 case-based questions of 4 marks each; and Section-E has 3questions of 5 marks each

(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 labeled diagrams should be drawn.

SECTION - A

1. Which of the following is the most widely accepted method of contraception in India at present.

(a) Cervical caps

(b) Tubectomy

(d) Intra uterine devices

2. Match column I with column II and select the correct option from the codes given below.

Column I Column II

A. Fertilization 1. Morula

B. Cleavage 2. Vagina

C. Blastocyst 3. Ampulla of oviduct

D. Parturition 4. Uterine Wall

(a) A-(iv), B-(i), C-(ii), D-(iii)

(b) A-(ii), B-(i), C-(iv), D-(iii)

(d) A-(iii), B-(i), C-(iv), D-(ii)

3.Which one of the following codons codes for the same information as UGC?

(a) UGU

(b) UGA

(d) UGG

4. The Hardy-Weinberg principle cannot operate if

(a) the population is very large

(b) frequent mutations occur in the population

(d) free interbreeding occurs among all members of the population..

5. In higher vertebrates, the immune system can distinguish self-cells and non-self. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to

(a) autoimmune disease

(b) active immunity

(d) graft rejection.

6. Select the correct option regarding a disease with us causal organism where haemozoin in released by the rupture of RBCs.

(a) Amoebiasis, Plasmodium vivax

(b) Malaria, Rhinovirus

(d) Pneumonia, Haemophilus influenzae

7. Which among these are produced by distillation of fermented broth?

(i) Whisky

(ii) Wine

(iii) Beer

(iv) Rum

(v) Brandy

(a) (ii) and (ii) only (b) (1) and (it) only (c) (iii) and (v) only (d) (1). (r) and (v) only

8. Children with Severe Combined Immunodeficiency Disorder (SCID) cannot produce many types of white blood cells that fight infections. This is because they do not have the functional gene to make the enzyme Adenosine Deaminase (ADA). Some children with SCID have been treated with stem cells as shown in the given flow chart.

Why are stem cells used in this treatment?

(a) Stem cells are capable of dividing for long periods to generate replacements for cells that are unable to produce ADA

(b) The stem cells used here belong to the child and there will be no triggering of immune response.

(c) Stem cells are unspecialized and can differentiate to specialized cell types such as white blood cells to fight infection.

(d) All of these

9. When an exotic species was introduced in an area, what may be the most probable effect?

A. The population of native species may decrease to very low level due to invasive alien species.

B.Introduced species may achieve highest population density due to lack of predation.

C Species develop favourable mutations.

D. New species evolved due to different environment.

(a) A and B are correct.

(b) A, C and D are correct.

(d) B, C and D are correct.

10. Tight one to one relationship between plant and pollinator is found in

(a). fig and wasp

(b) fungus and roots of Pinus

(d) all of these.

11. Which of the following representations shows the pyramid of numbers in a forest ecosystem?

(a) D

(b) A

(d) C

12. Which one of the following fish a being illegally introduced for aquaculture purposes and is posing a three to the indigenous catfishes of Indian rivers!

(a) Clarias gariepinus

(b) Nile perch

(d) Protopterus

Question No. 13 to 16 consist of two statements selecting the appropriate option given below. Assertion (A) and Reason (R). Answer these questions

(a) Both A and Rare true and is the correct explanation of A

(b) Bath A and R are true and Ris not the correct explanation of A.

(d) A is false but is true

13. Assertion: All copulation lead to fertilisation and pregnancy.

Reason: Semaltaneous transport of sperm and ovum in ampullary region results in fertilisation

14. Assertion Mendel conducted artificial pollination experiments for his genetic studies using true breeding pes lines

Reason: A true-breeding line shows the stable trait inheritance and expression for several generations

15. Assertion: Agrobacterium tumefaciens is the causative agent of crown gall disease of dicots.

Reason: Agnibacterium tumefaciens tramforms normal cell into tumour by inserting T.DNA.

16. Assertion: A population growing in a habitat with limited resources shows initially a lag phase, followed by phases of acceleration and deceleration and finally an asymptote, when the population density reaches the carrying capacity

Reason: In Verhulst-Pearl Logistic growth, plot of N (population density) at time (t) results in a sigmoid curve.

SECTION-B

17. The following figure shows a foetus within the uterus. On the basis of the given figure, answer the questions that follow.

(i) In the green figure identify the correct part among A. B. C and D that acts as a temporary endocrine gland and substantiate your answer. Why is it also called the functional junction?

(ii) Mention the role of B in the development of the embryo.

18. In Pisum sativum, the pod color may be green (G) or yellow (g) What percentage of offsprings with green pod color trait would be obtained in a cross of Gg* Gg.

19. (a) What precautions would you recommend to a patient requiring repeated blood transfusion?

(b) If the advise is not followed by the patient, there is an apprehension that the patient might contract a disease that would destroy the immune system of his\ her body Explain with the help of schematic diagram only how the immune system would get affected and destroyed.

20. What are recombinant proteins How do bioreactors help in their production!

21. Construct a pyramid of biomass starting with phytoplanktons. Label 3 trophic levels. Is the pyramid upright or inverted? Give reason.

Construct an ideal pyramid of energy when 100.000 joules of sunlight is available. Label all its trophic levels.

SECTION-C

22. When does the corpus luteum degenerate? Explain the immediate consequences of its degeneration in human female.

23. Describe the development of endosperm in coconut.

24. Refer to the given figure of lac operon and answer the following questions.

(a) Name the molecule 'X' synthesized by 'i' gene. How does this molecule get inactivated?

(b) Which one of the structural genes codes for B-galactosidase?

25. Explain convergent evolution taking one example for plants.

26. (a) The barriers in the innate immunity are given in the following table. Identify A. B. C. and D.

(b) Why sharing of injection needles between two individuals is not recommended?

Write the scientific names of the causal organisms of amoebiasis, elephantiasis and ringworm in humans. Mention the body parts affected by them.

27. (a) Identity A. B. C and D in the flow chart given below that represents the process of recombinant DNA technology

(b) State the role of C in biotechnology

28. Explain, giving one example, how co extinction is one of the causes of loss of biodiversity. List the three other causes also (without description).

SECTION-D

Q.No. 29 and 30 are case based questions. Each question has 3 subparts with internal choice in one subpart

29. Mendelism has certain limitations Each trait controlled by atleast two alleles is not universally applicable. There are few exceptions to law of dominance which was discovered after Mendel. Incomplete dominance and codominance are such examples.

(a) Identify X. Y and Z in the given table.

Give one example where Y pattern of inheritance is seen.

(b) Discuss inheritance pattern of ABO blood groups shown by humans.

(c) Name the pattern of inheritance shown by flower colour of snapdragon. Explain with the help of cross upto F2 generation.

30. Villagers in a place near Chambur started planning to make power supply for agricultural purposes from cow dung. They have started a biogas plant for the purpose. Study the given flow chart for biogas production and answer the following questions.

(a) Name the group of bacteria (A) responsible for biogas production.

(b) What is the composition of biogas?

Why biogas production is more common in rural areas?

SECTION E

31. Mention the role of gonadotropins in menstrual cycle. On what day of the menstrual cycle do the gonadotropins reach a peak

Angiosperm flowers may be monoecious, cleistogamous or show self incompatibility. Describe the characteristic features of each one of them and state which one of these flowers promotes inbreeding and outbreeding.

32. (a) What is a genetic code?

(b) Explain the following:

(i) Degenerate codon (ii) Unambiguous codon (iii) Initiator codon

Name and describe the technique that will help in solving a case of paternity dispute over the custody of a child by two different families.

33. (a) A recombinant vector with a gene of interest inserted within the gene of B-galactosidase enzyme, is introduced into a bacterium. Explain the method that would help in selection of recombinant colonies from non recombinant ones.

(b) Why is this method of selection referred to as "insertional inactivation"?

Rahul war having a debate with Rohan regarding the advantages and disadvantages of transgenic animals. Rahul viewed that the production of transgenic animals violates the integrity of species and animals suffer from cruelty so, it is unethical. On the other hand, Rohan emphasised the benefits that transgenic animals provide to the human race in various fields especially medicine

(a) How do transgenic animals benefit humans?

(b) List the ethical issues related with the production of transgenic animals.

BIOLOGY SAMPLE PAPER (044)