Download INDIAN SCHOOL AL WADI AL KABIR SECOND REHEARSAL

INDIAN SCHOOL AL WADI AL KABIR
SECOND REHEARSAL EXAMINATION
CLASS XII
DATE: 27.1.2015
BIOLOGY - 044
SET I
Maximum Marks: 70
Time: 3HRS
General Instructions
(i) All questions are compulsory.
(ii) This question paper consists of five sections SectionA contains 5 question's of one mark each
Section B contains 5 questions of two marks each, Section C contains 12 questions of three
marks each, Section D contains one question of fourmarks and, section E contain's 3 question's
of five mark's each.
(iii) There is no overall choice However an internal choice has been provided in one question of
2 marks, one question of 3 marks and, all three questions of 5 marks weightage.
iv) A student has to attempt only one of the alternatives in such questions.
v) Wherever necessary the diagrams drawn should be neat and well labeled.
vi)Please check that this question paper contains 26 questions.
Section A
1)Name the type of pollination in which genetically different types of
pollen grains of the same species land on the stigma.
2)In what way are the monocytes a cellular barrier in providing immunity?
3)What causes the swelling of the lower limbs in patients suffering from filariasis?
4) Why should hybrid seeds be produced every year?
5)Name the following:
(a) An interspecific hybrid of mammal.
(b) The semidwarf wheat variety that is high yielding and disease-resistant.
SECTION.B
6) What are the two core technologies that enabled the birth of modern
biotechnology?
Or
What is meant by continuous culture system? What is its advantage?
7)Plants in general occupy the first trophic level in a food chain; but in a certain
other type of food chain, they occupy the second trophic level. Justify this
statement and represent that type of a food chain.
8) Give reason.
(a) Which of the two, an annual or a perennial, has a shorter juvenile phase? Give
reason.
(b) Why do internodal segments of sugarcane fail to propagate vegetatively even
when they are in contact with damp soil?
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9) (a) State the principle on which ELISA works.
(b) What is a recombinant protein?
10)How is PCR used to detect gene mutation in case of patients who are suspected
to have cancer?
SECTION C
11) a) Thermoregulation is more efficient in larger animals than in smaller
animals, Explain
(b) Mention any two significant roles that predation plays in an ecosystem.
12)Explain amino acylation of tRNA. Mention its role in translation.
13(a) Explain divergent evolution taking examples from plants.
(b) What does Hardy-Weinberg equation convey?
14(a) The meiotic division that occurs during oogenesis is different from that
occurs during spermatogenesis. Explain
b) Where does each of the following hormones act, during spermatogenesis in a
human male?
i) GnRH
ii)FSH.
15a) A male honey bee (drone) has no father but has a grandfather'. Justify the
statement'
(b) An anther with a malfunctioning tapetum often fails to produce viable male
gametophytes, justify this statement.
16. (a) Why is MOET considered to be a successful programme in cattle breeding?
(b) What is meant by'superior' male and 'superior' female cattle selected for this
programme.
(c) Why is the cow administered with FSH-like hormones?
17) A segment of DNA, GCC AGG GGG ATG was translated into an
oligopeptide- Arginine-Serine-Proline-Tyrosine
i) Write the codons for these four amino acids'
(ii)If the first adeninein the DNA segment is substituted by guanine, What will be
the mRNA transcribed by it?
(iii)What will be the sequence of amino acids in the new oligopeptide?
(iv) Write the anticodons for these amino acids'
18)Name the type and give the effects of the following drugs on humansA ) LSD
B) Morphine
C) Barbiturate
19)Explain the three basic steps involved in a single PCR amplification cycle.
20)Who showed experimentally that it is DNA and not protein, the
genetic material ,Describe the experiment.
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21)Avector is engineered with three features, which facilitate its cloning into the
host cells. List and explain the three features.
22)Answer the following questions with reference to the given pedigree
i) Is the trait autosomal dominant, autosomal recessive or sex-linked?
ii) What is the genotypes of the parents.
iii) Give the genotype of the daughter in the first generation and the son and the
daughters in the second generation
Section D
23)A farmer has been growing paddy of in his small field season after season. He
is sad that the yield of paddy from his field has decreased considerably. Raju, a
final year student of B.Sc. (Agriculture) of the same village advises the farmer to
grow a pulse crop after a paddy and add Nostoc to the paddy crop
(a) What could be the reason according to you, for the decreasing yield of paddy
crop? what is such a practice called?
ft) How can the practice of growing a pulse crop between two paddy crops help to
increase the yield of paddy crops? what is this practice known as?
(c) How can Nostoc help to increase the yield of paddy crops?
(d) Mention the values shown by Raju towards the farmer.
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Section E
24)iYour friend would like to cross-pollinate the bisexual flower. How can you
guide him to be successful in his experiment?
ii)T.S. of anther shows four layers in the wall-epidermis, endothelium, tapetum and
middle layer. Arrange them from outermost to innermost
(iii) How many male gametes and female gametes are produced by –
a) 5 Microspore mother cells
b) 5 megaspore mother cells
iv) ) Draw a neat and labeled diagram showing a mature embryo of grass.
Or
Give reasons:- i). zona pellucida layer block the entry of additional sperms?
ii) sperm cannot reach ovum without seminal plasma?
iii) all copulations do not lead to fertilization and pregnancy?
iv) Draw a neat and labeled diagram showing a section of seminiferous tubule.
25)i What is the significance of the process of RNA interference in eukaryotic
organisms.
ii) Explain how this process is used in pest control programmes.
iii)Differentiate between plasmid DNA and chromosomal DNA.
Or
i)Differentiate between point mutation and frame shift mutation , give one example
of each.
ii)Define aneuploidy, how is it different from polyploidy.
iii)Identify the chromosomal abnormalities of : a)Trisomy of 21st chromosome.
b)XO individual.
26)i Draw an age pyramid for a zero population growth rate.
ii) Write the unit of measuring the population density of the following;
a)Bacteria
b)Banyan
c)Dear
d)Fish
iii)State any two ill effect of UV-B radiations.
Or
i)Explain the causes, inheritance patterns and symptoms of the following genetic
disorders : a)Sickle cell anaemia
b)Haemophilia
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