SECTION - A- How is the entry of only one sperm, and not
many, ensured into an ovum, during fertilization in
humans? - Name one autosomal dominant and one autosomal
recessive Mendelian disorder in humans. - Why is hnRNA required to undergo splicing?
- What is tissue-typing in organ transplantation in
humans? - Why is it desirable to use unleaded petrol in vehicles,
fitted with catalytic converters?
SECTION - B - Fertilization is essential for production of seed,
but in some angiosperms, seeds develop without
fertilization.
(i) Give an example of an angiosperm that produces seeds
without fertilization. Name the process.
(ii) Describe two ways by which seeds develop without
fertilization.
- (i) Both tape worm and earthworm are hermaphrodite.
How do they differ from each other with reference to
fertilization?
(ii) Mention the site where syngamy occurs in amphibians
and reptiles respectively.
OR
Mention two strategies evolved in flowering plants to
prevent self-pollination.- A non-haemophilic couple gave birth to a haemophilic
child (boy). The couple was informed by their doctor
that there is possibility of another haemophilic child
being born to them. Explain the basis on which the
doctor conveyed this information. Give the genotypes
and the phenotypes of all the possible children who
could be born to them. - Name the resistant varieties developed and the insects
to which these are resistant in case of the following
plants:
(i) Flat bean (ii) Okra - (i) How is ‘Rosie’ considered different from a normal cow?
(ii) Biotechnologists refer to Agrobacterium tumefaciens
as a natural genetic engineer of plants. Give reasons to
support the statement.
SECTION - C - Trace the development of megaspore mother cell up to
the formation of a mature embryo-sac in a flowering
plant.
GENERAL INSTRUCTIONS
(i) All questions are compulsory.
(ii) This question paper consists of five Sections A, B, C, D and E. Section A contains 5 questions 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 1 question of VBQ type
with four marks and Section E contains of 3 questions of five marks 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 the three questions of 5 marks weightage. A student has to attempt only one of the alternatives in such questions.
(iv) Wherever necessary, the diagrams drawn should be neat and properly labelled.