18.Make a list of any three outbreeding devices that
flowering plants have developed and explain how
they help to encourage cross-pollination.
19.Write a note on mutualism with examples.
20.If implementation of better techniques and new
strategies are required to provide more efficient
care and assistance to people, then why there is a
statutory ban on amniocentesis? Write the use of
this technique and give reason to justify its ban.
- (i)Why are grasshopper and Drosophila said to
show male heterogamety? Explain.
(ii)Explain female heterogamety with the help of
an example.
22.Read the following base sequence of a certain DNA
strand and answer the question that follow:
A A G A A T T C A A
T T C T T A A G T T(i)What is called a palindromic sequence in a
DNA?
(ii)Write the palindromic nucleotide sequence
shown in the DNA strand given and mention the
enzyme that will recognise such a sequence.
(iii)State the significance of enzymes that identify
palindromic nucleotide sequences.Section-D
23.During biology class, teacher was telling about
microbes and how they are useful for humans.
Hearing this, Harry got confused as he knew that
microbes are dangerous and can only cause
diseases. He asked his teacher about it. The
teacher appreciated him for his question and
explained the whole class.
(i)What are microbes?
(ii)How are microbes helpful to humans? Explain.
(iii)Name one microbe that is used as
(a)household products
(b)biofertiliser
(iv)Identify the values shown by teacher.
Section-E
24.How do ‘Pleiotropy’, in com plete dom i nance,
‘codom i nance’ and polygenic inheritance deviate
from the observation made by Mendel? Explain
with the help of example for each.
or
Any recombinant DNA with desired gene is
required in billion copies for commercial use. How
is the amplification done? Explain.- (i)How is ‘oogenesis’ markedly different from
‘spermatogenesis’ with respect to the growth
till puberty in the humans?
(ii)Draw a sectional view of human ovary and
label the different follicular stages, ovum and
corpus luteum.
or
What is organic evolution? Give the evidences of
organic evolution. - (i)Explain the narrow utilarian, broadly
utilarian and ethical arguments in favour of
conservation of biodiversity.
(ii)How is designation of certain areas as hot
spots, a step towards biodiversity
conservation? Name any two hot spots in
India.
or
(i)Cancer is one of the most dreaded diseases.
Explain ‘contact inhibition and metastasis’
with respect to the disease.
(ii)Name the group of genes that have been
identified in normal cells that would lead to
cancer. How do these genes cause cancer?
(iii)Name any two techniques that are useful in
detecting cancers of internal organs.
(iv)Why are cancer patients, often given
α-interferon as part of the treatment?
WBJEE will be on May 17, 2016
West Bengal Joint Entrance Examinations Board
(WBJEE Board) has released information
brochure of WBJEEM 2016 on December 24, 2016.
According to the WEBJEEM 2016 brochure,
the Application form for WBJEEM 2016 will be
available from January 5, 2016 onwards. WBJEEM
2016 will be conducted by the board on May 17,
2016 for admission to undergraduate level
professional courses in Engineering, Technology,
Architecture and Pharmacy in government
colleges and self-financed institutes in West
Bengal.The information brochure contains
important details related to the entrance exam
like Question Pattern, Ranking and tie breaking,
Eligibility criteria for candidates, Availability of
seats, Application Procedure, Important Dates,
Admit Card ̧ Counselling and Admission,
Syllabus etc.