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BIOLOGY
Class
II PU
Paper-4
Max. Marks
Duration
70
3 hrs
Instructions
1. This question paper consists of five parts A, B, C, D and E.
2. All the Parts are Compulsory.
3. Draw diagrams whenever necessary. Unlabelled diagrams or illustrations do not attract any marks.
PART - A
I.
Answer all the following
[10  1 = 10]
1. What is divergent evolution?
Solution
Evolution of new species due to migration (diversion) of individuals from a common ancestral stock into
new habitats is called divergent evolution.
2. Which hormone induces ovulation in mammals?
Solution
Lutenizing/Luteotropic hormone.
3. Define spermeogenesis.
Solution
Transformation of non-motile spermatids into motile sperms or spermatozoa is called spermeogenesis.
4. Secondary succession is faster than primary succession. Why?
Solution
Secondary succession begins in a place which already has favourable abiotic conditions such as soil
nutrients, water etc., and therefore it is faster than primary succession.
5. Give an example for “once a week non steroidal oral pill”.
Solution
“Saheli”
6. State Allen’s rule?
Solution
Mammals living in colder regions have shorter ears and limbs than those of tropics, so that they can
minimize loss of heat from their body.
7. What are somaclones?
Solution
Identical plants (plantlets) produced by micropropagation are called somaclones.
8. Streptokinase is known as clot buster. Give reason.
Solution
It is used to remove/dissolve blood clots in blood vessels and hence called clot buster.
1
9. Name the organism from which Bt genes were isolated.
Solution
Bacillus thuriengiensis.
10. Who proposed the chromosomal theory of inheritance?
Solution
Boveri and Sutton.
PART - B
II. Answer any FIVE of the following
[5  2 = 10]
11. What is primary immune response? How does it differ from secondary immune response?
Solution
Immune response developed after first encounter with a pathogen is called primary immune response. It
is usually slow and mild response.
[1]
Immune response developed after second or subsequent encounters with a pathogen is called secondary
response. It is quick and intense.
[1]
12. Define life span and mention the phases in it.
Solution
The period (duration) from birth to the natural death.
Important phases during life span are: Juvenile phase or vegetative phase, Reproductive phase and
senescent phase.
[1]
[1]
13. Genes in eukaryotes are called split genes. Why? Mention the significance of split genes.
Solution
In eukaryotes, structural genes contain coding regions (exons) and non coding regions (introns)
alternately genes. The presence of introns indicates the antiquity of species. (ancient feature of genome).
[1]
14. Mention the objectives of plant breeding.
Solution
Objectives of plant breeding : To increase quality and quantity, tolerance to environmental fluctuations,
resistance to diseases and pests and earliness.
[½ mark each]
15. What are solid wastes? How are the solid waste categeorised?
Solution
Solid waste refers to all the waste products which goes out in thrash.
Solid waste can be categorized as:
Dry-degradable and non-degradable
(1) Municipal waste
Wet-degradable and non-degradable
(2) Hospital waste
(3) e-Waste
[1]
[½ mark each]
16. Distinguish between dominant and recessive character.
Solution
Two valid differences.
2
17. What are the significances of higher diversity in an ecosystem?
Solution
Stable productivity, resistance to environmental stress, better ecosystem services and ecosystem health.
[½ mark each]
18. List any four methods followed in Assisted Reproductive Technology.
Solution
AI / GIFT / ZIFT / IVF-ET / ICSI
[Any four ½ mark each]
PART - C
III. Answer any FIVE questions
[3  5 = 15]
19. What is dairy farm management? List the measures to be taken for a successful dairy farm management.
Solution
Definition
[1 mark]
Measures
[2 marks]
20. Write a short note on cause and effects of Phenylketonurea.
Solution
Cause of PKU
[1 mark]
Effects
[2 marks]
21. (a) What are oral contraceptives?
(b) What are emergency contraceptives?
(c) How do contraceptive pills prevent conception?
Solution
(a) Definition
[1 mark]
(b) Definition
[1 mark]
(c) They prevent (inhibit) ovulation by disrupting the hormonal mechanism of follicular growth.
[1 mark]
22. What is endosperm? Explain formation of endosperm in coconut.
Solution
Definition
[1 mark]
Explanation of free nuclear, endosperm formation
[2 marks]
23. What does GEAC stand for? Write a short note on biopiracy with suitable examples.
Solution
Genetic Engineering Approval Committee
[1 mark]
Definition of biopiracy with an example
[2 mark]
24. (a) What is resource partitioning? Explain with example.
(b) India is said to have greater biodiversity than Norway. Justify.
Solution
(a) Variations or differences in preferences and activities to avoid competition among the members of
closely related species is called resource partitioning.
(b) In India there is greater variety of habitat compared to Norway.
3
[1 mark]
[1 mark]
25. Define and explain insertional inactivation with respect to rDNA technology.
Solution
Tracing the recombined (transformed) competant hosts from the non-recombined, due to inactivation of
a “marker gene” in transformed hosts is called insertional inactivation.
[1 mark]
Explanation with a suitable example.
[2 marks]
26. Define the following;
(a) Population density.
(b) Sex ratio.
(c) Natality.
Solution
Correct definition
[1 mark each]
PART - D
Section - I
IV. Answer any FOUR of the following
[4  5 = 20]
27. What is HGP? Mention the goals and features of HGP.
Solution
Definition
[1 mark]
Goals of HGP
[4 marks]
28. Draw a neat labeled diagram T.S. testis and mention the location and functions Leydig cells.
Solution
Neat labelled diagram of T.S of testis
[4 marks]
Proper location and function of leydig cell
[1 mark]
29. (a) What are out-breeding devices? Explain any two such devices in angiosperms with examples.
(b) Distinguish between seasonal and non seasonal breeders with suitable examples.
Solution
(a) Devices or methods of avoid self pollination and ensure cross pollination are called outbreeding
devices.
[1 mark]
Dichogamy/self-incmpatibitly/Heterostyly/Herkogamy and two methods with suitable examples.
[1+ 1 mark]
(b) Any two valid differences.
[2 marks]
30. (a) With a neat labeled diagram describe structure of a t-RNA (adapter) molecule.
(b) Mention the different levels of gene regulation in eukaryotes.
Solution
(a) Diagram with proper labellings
[2 marks]
(b) Transcription level, post transcription level, transportation of mRNA to cytosol or transulation level.
[½ mark each]
31. (a) Mention three differences between external and internal fertilization.
(b) Offspring of asexual reproducing organisms are referred as clones. Why?
(c) Vegetative propagation is a type of asexual reproduction in higher plants. Justify.
4
Solution
(a) Any three valid differences
[2 marks]
(b) Because offspring are identical to their parent both morphologically genetically
[1 mark]
(c) Propugules grow into new plants by mitosis
[1 mark]
32. What are controlled animal breeding techniques? Describe Artificial insemination and MOET techniques
along with the significances.
Solution
Artificial breeding experiments carried out for the improvement of productivity of live-stock are called
controlled breeding techniques.
[1 mark]
Method and advantages of Artificial insemination
[2 marks]
Method and advantages of MOET
[2 marks]
PART - E
Section - II
V. Answer any THREE of the following
[3  5 = 15]
33. (a) Define allergy.
(b) What are allergens? Mention two examples.
(c) How does allergy differ from autoimmunity?
Solution
(a) Definition
[1 mark]
(b) Substance which induce allergic response are allergens
[1 mark]
Examples
[½ + ½]
(c) Allergy is due to a non-pathogenic foreign substance but auto immunity is due inability of acquired
immune system to recognize self cells.
[1 mark]
Allergies develop during life time auto immunity is by birth
[1 mark]
34. What is Joint forest management programme? Give a brief account of two incidents which narrate
participation of people in conservation of forest.
Solution
A concept introduced by the Government of India for the protection and management of forest by
involving local (tribal) communities.
[1 mark]
Bishnois incident
[2 marks]
Chipko movement
[2 marks]
35. (a) Define sere.
(b) What is hydrarch succession? Mention seral stages of plants which occur during hydrosere.
Solution
(a) Definition
[1 mark]
(b) Progressive change in the communities which occupy a aquatic habitat is called hydrarch succession
[1 mark]
Phytoplankton, stage, submerged plant stage, submerged free floating plant stage, red swamp stage,
March-meadow stage, scrub stage, forest.
[3 marks]
36. (a) What is air pollution? Mention its effects and control measures.
5
(b) Write a note on a case of integrated waste water (sewage) management.
Solution
(a) Definition
[½ mark]
Effects of air pollution on plants, animals, humans and monuments
[2 marks]
Control measures – cyclone separator, electrostatic precipitator, scrubber and use of catalytic
converter
[1 ½ mark]
(b) Explanation on Areata marshy sanctuary waste management
37. Write a brief account of evolution of different vertebrates.
Solution
Evolution of fishes
[1 mark]
Amphibians
[1 mark]
Reptiles
[1 mark]
Birds
[1 mark]
Mammals
[1 mark]
***
6
[1 mark]