Roll No.
________________ Code : 11201819B-A
Please check that this question
paper contains 27 questions
Class : XI and 4 printed pages.
biology
Time Allowed : 3 Hours Maximum Marks : 70
General Instructions :
1. All the questions are compulsory.
2. The question paper consists of four sections A, B, C and D.
3. Internal choice is given in all the sections. A student has to attempt only one of the
alternatives in such questions.
4. Section-A contains 5 questions of 1 mark each.
5. Section-B has 7 questions of 2 marks each.
6. Section-C is of 12 questions of 3 marks each.
7. Section-D has 3 questions of 5 marks each.
8. Wherever necessary, the diagram drawn should be neat and properly labelled.
9. Fifteen minutes reading time has been alloted to read the question paper. Students will
not write anything during this time.
section - a
1. Name an organism which is photosynthetic, but when deprived of sunlight
acts as a heterotroph. 1
or
Name the most abundant protein present in the animal world.
2. Give the taxonomical genus and order of housefly. 1
3. Name the plant tissue that provides mechanical support to the growing parts of
the plant, such as the petiole of a leaf. 1
4. Name the type of linkage by which the monomers in the following
macromolecules are held together : 1
(a) Polysaccharides
(b) Polypeptides
5. Give a diagrammatic representation of the amino acid serine. 1
or
Give a diagrammatic representation of the nucleoside adenosine.
section - b
6. Describe the characteristic features of pachytene stage of prophase of Meiosis I. 2
or
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Write a note on the stage termed diakinesis of prophase of Meiosis I
7. Given below is a table showing the process of digestion in man. Fill in the
blanks (a–d) with [correct] answers. 2
Enzyme Site of action Substrate End Product/s of action
(a) Stomach Protein Peptones / Proteoses
Lipase Small intestine Fat (b)
(c) Small intestine Nucleic acid Nucleotides and Nucleosides
The region of small Proteins, Peptones
Trypsin Dipeptides
intestive – (d) and Proteoses
8. (a) Name two hormones which are commonly called catecholamines?
(b) Give two effects caused by the release of the above hormones during
emergency situations in our body. 2
9. "Double fertilisation is an event unique to the angiosperms". Explain. 2
or
"Heterospory in some pteridophytes as Salvinia has an evolutionary
significance." Explain.
10. Study the figure given below in which the A B
Solute
two chambers A and B, containing solutions molecule
are separated by a semipermeable membrane.
Answer the given following questions. Water 2
(a) Solution of which chamber has a lower water potential? Semi-permeable
(b) In which direction will osmosis take place? membrane
(c) Solution of which chamber has a lower solute potential?
(d) At equilibrium which chamber will have lower water potential?
11. (a) Draw citric acid cycle and specify the reaction catalysed by citrate
synthase in Krebs' cycle.
(b) A farmer has added Azotobacter culture to soil before sowing maize.
Which mineral element is being replenished by adding the culture? 2
12. Differentiate between the following terms -
(a) Ligases and Lyases
(b) Deoxyribonucleic acid and Ribonucleic acid. 2
section - C
13. Name the phylum to which the following animals belong to. 3
(a) Pleurobrachia (b) Ancylostoma
(c) Pila (d) Petromyzon
(e) Physalia (f) Limulus
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14. Name and describe the type of root modifications observed in a banyan tree
and Sugarcane. 3
or
Name and describe the type of phyllotaxy observed in Calotropis and Alstonia.
15. (a) Observe the given diagram (ii) 3
of Malpighian body and label
(iii)
the parts (i–iv). (i)
(iv)
(b) Both pigeon and a cat were fed on a protein diet. In what major forms,
would they excrete their nitrogenous wastes?
16. (a) Why do myofibrils of a sketetal muscle show striated appearence? Explain.
(b) Explain the role of calcium ions and ATP hydrolysis in muscle
contraction. 3
or
Write a note on anatomical structure of a scapula bone of the pectoral girdle.
17. (a) Justify giving reasons - 3
(i) GA3 is applied to juvenile conifers.
(ii) A ripe fruit when mixed with unripe fruits hastens fruit ripening.
(b) Differentiate between arithmetic and geometrical growth rate.
18. (a) What is the significance of mitosis? Enlist any two points.
(b) State the important events taking place during S phase in an animal cell. 3
19. (a) Name the specific type of connective tissue associated with the storage
of fats. Where is it located?
(b) Draw a well-labelled diagram of cardiac muscle tissue showing
communication junctions and state their significance. 3
or
Where are the following epithelial tissues found in an animal cell? Give one
example of each and give their diagram.
(a) Squamous epithelium
(b) Cuboidal epithelium
(c) Ciliated columnar epithelium
20. (a) Give the scientific term used for the type of chromosome having -
(i) Centromere in the middle forming two equal arms of the
chromosomes.
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(ii) Centromere is situated close to the ends of the chromosome
forming one extremely shorter arm and one very long arm.
(b) What is a mesosome in a prokaryotic cell? State its any two functions.
(c) SER is mainly involved in the synthesis of which biomolecule? 3
21. (a) How are prosthetic groups different from co-enzymes?
(b) State the changes that take place during the action of an enzyme when
the temperature is low and when the pH of the medium is optimum. 3
22. (a) "Minerals are absorbed by the plants in the form of ions". In which
form are sulphur and phosphorus taken up by the plants?
(b) Justify giving two reasons how excess of manganese in soil induce
deficiencies of iron, magnesium and calcium. 3
23. (a) Define fermentation.
(b) Explain and draw the symplastic pathway of movement of water in
plants. 3
or
T.W. Engelmann performed the experiment on the basis of which the first
action spectrum of photosynthesis was described. Describe the experiment.
24. (a) Enlist the three layers of neural cells of retina from inside to outside.
(b) Write any three functions controlled by limbic system in association with
the hypothalamus. 3
section - D
25. Describe briefly the anatomy of dicotyledonous leaf with the help of a
labelled diagram. 5
or
(a) Draw a well-labelled diagram of female reproductive system of a
cockroach.
(b) How do the nymphs of cockroach differ from adult cockroach?
26. Describe the regulation of cardiac activity in man. 5
or
Explain the mechanism of inspiration under normal conditions in man.
27. Describe the process of Non-cyclic Photo-phosphorylation. What is the
specific location in the chloroplast where it takes place? 5
or
Explain the mechanism of membrane-linked ATP synthesis during respiration
in plants. In which form pyruvic acid is converted into before it enters the
Krebs' cycle?
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