1. Which One of the Following Is an Artificial Ecosystem?

Class-X- BIOLOGY

1. Which one of the following is an artificial ecosystem?

(a) Pond (b) Crop field

2. In a food chain, the third trophic level is always occupied by

(a) carnivores (b) herbivores

3. An ecosystem includes

(a) all living organisms

(b) non-living objects

(d) sometimes living organisms and sometimes non-living objects

4. In the given food chain, suppose the amount of energy at fourth trophic level is 5 kJ, what will be the energy available at the producer level?

Grass → Grasshopper → Frog → Snake → Hawk

(a) 5 k J (b) 50 k J

5. Accumulation of non-biodegradable pesticides in the food chain

in increasing amount at each higher trophic level is known as

(a) Eutrophication (b) pollution

6. Depletion of ozone is mainly due to

(a) chlorofluorocarbon compounds (b) carbon monoxide

7. Organisms which synthesise carbohydrates from inorganic compounds using radiant energy are called

(a) decomposers (b) producers

8. In an ecosystem, the 10% of energy available for transfer from one

trophic level to the next is in the form of

(a) heat energy (b) light energy

9. Organisms of a higher trophic level which feed on several types of

organisms belonging to a lower trophic level constitute the

(a) food web (b) ecological pyramid

10. Flow of energy in an ecosystem is always

(a) unidirectional (b) bidirectional

11. Excessive exposure of humans to U V-rays results in

(i) damage to immune system (ii) damage to lungs

(iii) skin cancer (iv) peptic ulcers

(a) (i) and (ii) (b) (ii) and (iv)

12. In the following groups of materials, which group (s) contains only non-biodegradable items?

(i) Wood, paper, leather (ii) Polythene, detergent, PVC

(iii) Plastic, detergent, grass (iv) Plastic, bakelite, DDT

(a) (iii) (b) (iv)

13. Which of the following limits the number of trophic levels in a food chain?

(a) Decrease in energy at higher trophic levels (b) Dufficient food supply

14. Which of the statement is incorrect?

(a) All green plants and blue green algae are producers

(b) Green plants get their food from organic compounds

(d) Plants convert solar energy into chemical energy

15. Which group of organisms are not constituents of a food chain?

(i) Grass, lion, rabbit, wolf (ii) Plankton, man, fish, grasshopper

(iii) Wolf, grass, snake, tiger (iv) Frog, snake, eagle, grass, grasshopper

(a) (i) and (iii) (b) (iii) and (iv)

16. The percentage of solar radiation absorbed by all the green plants

for the process of photosynthesis is about

(a) 1 % (b) 5 %

17. In the given Figure 15.1 the various trophic levels are shown in a

pyramid. At which trophic level is maximum energy available?

(a) T4 (b) T2

18. What will happen if deer is missing in the food chain given below?

Grass → Deer → Tiger

(a) The population of tiger increases

(b) The population of grass decreases

(d) The population of tiger decreases and the population of grass increases

19. The decomposers in an ecosystem

(a) convert inorganic material, to simpler forms

(b) convert organic material to inorganic forms

(d) do not breakdown organic compounds

20. If a grass hopper is eaten by a frog, then the energy transfer will be from

(a) producer to decomposer

(b) producer to primary consumer

(d) secondary consumer to primary consumer

21. Disposable plastic plates should not be used because

(a) they are made of materials with light weight

(b) they are made of toxic materials

(d) they are made of non-biodegradable materials

22. Why is improper disposal of waste a curse to environment?

23. Write the common food chain of a pond ecosystem.

24. What are the advantages of cloth bags over plastic bags during shopping?

25. Why are crop fields known as artificial ecosystems?

26. Differentiate between biodegradable and non-biodegradable substances.Cite examples.

27. Suggest one word for each of the following statements/ definitions

(a) The physical and biological world where we live in

(b) Each level of food chain where transfer of energy takes place

(d) Organisms which depend on the producers either directly or indirectly for food

28. Explain the role of decomposers in the environment?

29. Select the mis-matched pair in the following and correct it.

(a) Biomagnification — Accumulation of chemicals at the successive trophic levels of

a food chain

(b) Ecosystem — Biotic components of environment

(d) Parasites — Organisms which obtain food

from other living organisms

30. We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why?

31. Indicate the flow of energy in an ecosystem. Why is it unidirectional? Justify.

32. What are decomposers? What will be the consequence of their absence in an ecosystem?

33. Suggest any four activities in daily life which are eco-friendly.

34. Give two differences between food chain and food web.

35. Name the wastes which are generated in your house daily. What measures would you take for their disposal?

36. Suggest suitable mechanism (s) for waste management in fertilizer industries.

37. What are the by-products of fertiliser industries? How do they affect the environment?

38. Explain some harmful effects of agricultural practices on the environment.

Class –XI BIOLOGY

1. Formation of enzyme-substrate complex (ES) is the first step in catalysed reactions. Describe the other steps till the formation of product.

2. What are different classes of enzymes? Explain any two with the type of reaction they catalyse.

3. Nucleic acids exhibit secondary structure. Describe through Wetson-Crick Model.

4. What is the difference between a nucleotide and nucleoside? Give two examples of each with their structure.

5. Describe various forms of lipid with a few examples.

6. What part of the plant would show the following:

a. Radial vascular bundle

b. Polyarch xylem

c. Well developed pith

7. What are the cells that make the leaves curl in plants during water stress?

8. What constitutes the cambial ring?

9. Give one basic functional difference between phellogen and phelloderm.

10. Arrange the following in the sequence you would find them in a plant starting from the periphery – phellem, phellogen, phelloderm.

11. If one debarks a tree, what parts of the plant is being removed?

12. The cross-section of a plant material showed the following features when viewed under the microscope.

a. The vascular bundles were radially arranged.

b. Four xylem strands with exarch condition of protoxylem.

To which organ should it be assigned?

13. What do hard wood and soft wood stand for?

14. What are the characteristic differences found in the vascular tissue of gymnosperms and angiosperms?

15. Epidermal cells are often modified to perform specialized functions in plants. Name some of them and function they perform.

16. Distinguish between the following:

a. Exarch and endarch condition of protoxylem b. Stele and vascular bundle

c. Protoxylem and metaxylem d. Interfasicular cambium and intrafasicular cambium

e. Open and closed vascular bundles

17. Write the functions of the following

a. Centromere

b. Cell wall

c. Smooth ER

d. Golgi Apparatus

e. Centrioles

f. Stem hair and root hair

Class-XII -Biology

The vitamin whose content increases following the conversion of milk into curd by lactic acid bacteria is:

a. vitamin C

b. vitamin D

c. vitamin B12

d. vitamin E.

2. Wastewater treatment generates a large quantity of sludge, which can be treated by:

a. digesters b. activated sludge

c. chemicals d. oxidation pond.

3. Methanogenic bacteria are not found in:

a. rumen of cattle b. gobar gas plant

c. bottom of water-logged paddy fields d. activated sludge.

4. Match the following list of bacteria and their commercially important products: Bacterium Product

(i) Aspergillus niger (a) Lactic acid

(ii) Acetobacter aceti (b) Butyric acid

(iii) Clostridium butylicum (c) Acetic acid

(iv) Lactobacillus (d) Citric acid

Choose the correct match:

a. i b, ii c, iii d, iv a

b. i b, ii d, iii c, iv a

c. i d, ii c, iii b, iv a

d. i d, ii a, iii c, iv b

5. Match the following list of bioactive substances and their roles: Bioactive Substance Role

(i) Statin (a) Removal of oil stains

(ii) Cyclosporin A (b) Removal of clots from blood vessels

(iii) Streptokinase (c) Lowering of blood cholesterol

(iv) Lipase (d) Immuno-suppressive agent

Choose the correct match:

a. i b, ii c, iii a, iv d

b. i d, ii b, iii a, iv c

c. i d, ii a, iii d, iv c

d. i c, ii d, iii b, iv a

6. The primary treatment of waste water involves the removal of:

a. dissolved impurities b. stable particles

c. toxic substances d. harmful bacteria.

7. BOD of waste water is estimated by measuring the amount of:

a. total organic matter b. biodegradable organic matter

c. oxygen evolution d. oxygen consumption.

8. Which one of the following alcoholic drinks is produced without distillation?

a. Wine b. Whisky

c. Rum d. Brandy

9. The technology of biogas production from cow dung was developed in India largely due to the efforts of:

a. Gas Authority of India b. Oil and Natural Gas Commission

c. IARI and Khadi & Village Industries Commission d. Indian Oil Corporation.

10. The free-living fungus Trichoderma can be used for:

a. killing insects b. biological control of plant diseases

c. controlling butterfly caterpillars d. producing antibiotics

11. What would happen if oxygen availability to activated sludge flocs is reduced?

a. It will slow down the rate of degradation of organic matter

b. The center of flocs will become anoxic, which would cause death

of bacteria and eventually breakage of flocs.

c. Flocs would increase in size as anaerobic bacteria would grow around flocs.

d. Protozoa would grow in large numbers.

12. Mycorrhiza does not help the host plant in:

a. Enhancing its phosphorus uptake capacity

b. Increasing its tolerance to drought

c. Enhancing its resistance to root pathogens

d. Increasing its resistance to insects.

13. Which one of the following is not a nitrogen-fixing organism?

a. Anabaena b. Nostoc

c. Azotobacter d. Pseudomonas

14. Big holes in Swiss cheese are made by a:

a. a machine b. a bacterium that produces methane gas

c. a bacterium producing a large amount of carbon dioxide d. a fungus that releases a lot of gases during its metabolic activities.

15. The residue left after methane production from cattle dung is:

a. burnt b. burried in land fills

c. used as manure d. used in civil construction.

16. Methanogens do not produce:

a. oxygen b. methane

c. hydrogen sulfide d. carbon dioxide.

17. Activated sludge should have the ability to settle quickly so that it can:

a. be rapidly pumped back from sedimentation tank to aeration tank

b. absorb pathogenic bacteria present in waste water while sinking to the bottom of the settling tank

c. be discarded and anaerobically digested

d. absorb colloidal organic matter.

18. Match the items in Column ‘A’ and Column ‘B’ and choose correct answer.

(i) Lady bird (a) Methano bacterium

(ii) Mycorrhiza (b) Trichoderma

(iii) Biological control (c) Aphids

(iv) Biogas (d) Glomus

The correct answer is:

a) i b, ii d, iii c, iv a b) i c, ii d, iii b, iv a

c) i d, ii a, iii b, iv c d) i c, ii b, iii a, iv d

19. Which one is the most important role of micro organism for the well-being of humans?

a. sewage treatment b. production of methane

c. biological control of plant disease d. conversion of milk to curd.

1. Why does ‘Swiss cheese’ have big holes?

2. What are fermentors?

3. Name a microbe used for statin production. How do statins lower blood cholesterol level?

4. Why do we prefer to call secondary waste water treatment as biological treatment?

5. What for Nucleopolyhydro viruses are being used now a days?

6. How has the discovery of antibiotics helped mankind in the field of medicine?

7. Why is distillation required for producing certain alcoholic drinks?

8. Write the most important characteristic that Aspergillus niger,

Clostridium butylicum, and Lactobacillus share.

9. What would happen if our intestine harbours microbial flora exactly similar to that found in the rumen of cattle?

10. Give any two microbes that are useful in biotechnology.

11. What is the source organism for ECORI, restriction endonuclease?

12. Name any genetically modified crop.

13. Why are blue green algae not popular as biofertilisers?

14. Which species of Penicillium produces Roquefort cheese?

15. Name the states involved in Ganga action plan.

16. Name any two industrially important enzymes.

17. Name an immune immunosupressive agent?

18. Give an example of a rod shaped virus.

19. What is the group of bacteria found in both the rumen of cattle and shidge of sewage treatment?

20. Name a microbe used for the production of Swiss cheese.

21. Why is aerobic degradation more important than anaerobic degradation for the treatment of large volumes of waste waters rich in organic matter. Discuss.

22. (a) Discuss about the major programs that the Ministry of Environment and Forests, Government of India, has initiated for saving major Indian rivers from pollution.

(b) Ganga has recently been declared the national river. Discuss the implication with respect to pollution of this river.