Download LSE-06

evelopmental Biology
LSE-06
ASSIGNMENT
LSE-06
Assignment
from July
2007 2008)
to May 2008)
(Valid
from (Valid
July 2007
to May
Dear Student,
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To getthefeedbackonyourassignmenresponse,ywithinfmonthofthreceiptofthiassignmentbookleth
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We wish you good luck.
Bachelor in Science Programme
(B.Sc.)
DEVELOPMENTAL BIOLOGY
SCHOOL OF SCIENCES
Indira Gandhi National Open University
Maidan Garhi
New Delhi – 110 068
2007-2008
Developmental Biology
LSE-06
Assignment (Valid from July 2007 to May 2008)
Dear Student,
You are required to do one assignment for this elective course. The instructions for doing the
assignments are given in the Programme Guide under Section 7.1 Assignments. Please read the
instructions carefully before you start to prepare your assignment response.

You are required to submit your assignment response within fourteen weeks of the receipt of this
assignment booklet to the Coordinator of your Study Centre.

You are advised to retain a copy of your assignment response for your record.
Good luck.
2
ASSIGNMENT
Assignment Code: LSE-06/2007-08
Max. Marks: 100
1. Fill in the blank spaces with appropriate words.
i)
A true fruit develops from the ……………………… .
ii)
The age of a tree can be determined by studying its ………………. …………………… .
iii)
An outgrowth near the micropyle that guides the growing pollen tube into the ovule is
called ………….. .
iv)
In Mangifera indica several embryos originate from the ………..…. cells.
v)
The female gametophyte in the angiosperms is represented by ……………… ………………. .
vi)
The flowers that accomplish fertilization without exposing their sex organs to the atmosphere
are known as ……………….. .
vii) In the seeds of many aquatic plants the spongy …………………… provides buoyancy and
helps them to stay afloat.
viii) Apple is an example of …………….. fruit.
ix)
The pollination brought about by the agency of bats is referred to as ………………. .
x)
Vivipary occurs in …………………. .
(½×10)
2. List and illustrate the different layers comprising the anther wall and describe the functions
performed by each.
(1+1+1)
3. Describe using labelled diagrams any two adaptations in bisexual flowers for preventing
self-pollination.
(2)
4. i)
Distinguish between sporophytic and gametophytic self-incompatibility.
(1)
Detail the methods to overcome incompatibility in plants.
(2)
ii)
5. What is organogenesis? Discuss the role of plant hormones in this process.
6. Elaborate the physiological effects of naturally occurring plant growth regulators in plants.
(1+2)
(2)
7. With the help of clear and labelled diagrams, write short notes on the following:
i)
ii)
iii)
iv)
Secondary growth in dicot stems
Geotropism
Somatic embryogenesis
Applications of apical dominance in horticulture and agriculture
(2½×4)
8. Make clear, bold and labelled diagrams of the following:
i)
ii)
iii)
iv)
v)
A median longitudinal section of a mature embryo of Triticum.
L.S. of a shoot apex showing the Tunica and Corpus regions.
T.S. of a modified root of sweet potato.
The fine structure of a growing pollen tube.
Structure of secondary xylem in 3-dimensional view in Pinus.
9. Describe the structure and the role of the various seed appendages. Make labelled diagrams
for each of them.
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(2×5)
(2)
10. Differentiate between the following pairs of words with the help of both labelled diagrams and
description.
i)
ii)
Endothecium and endothelium
Nuclear and helobial types of endosperm
(2×2)
11. What are the advantages of the following in context of an angiospermous plant?
i)
ii)
Apomixis
Somatic hybridization
(2×2)
12. With the use of modern tools and techniques what new insights have been added to our prior
understanding about pollen biology?
(Please refer to the information given in both the Units # 2 and #12).
(2)
13. Give the answer in one to five words what that these definitions define.
i)
ii)
ii)
iv)
v)
14. i)
i)
ii)
iii)
iv)
Sexual reproduction in protozoans (protists) whose two nuclei of the same individual, each
representing a gamete fuse to form a zygote nucleus. It is a form of nuclear reorganization and
self fertilization.
The process of intracellular differentiation of spermatid into a spermatozoa.
The embolic morphogenetic movement in gastrulation which involves the process of insinking
or infolding of the presumptive endodermal area.
In holometabolous insect larvae, the rudiments of future organs of adults such as mouth,
parts, wing, antennae, walking legs etc.
The one type of stem cell from which all types of blood cells in birds and mammals are
derived.
(2×5)
Give the result of these experiments and explain these results.
If Hydra is transversely sliced into annular segments.
The scientist McKinnel (1962) in his experiments, transplanted the blastula nuclei into
enucleated eggs.
Spemann and his coworkers in newt of genus Triturus grafted a piece of prospective neural
ectoderm from an early gastrula stage donor embryo into a region of host embryo where belly
skin should develop.
In chick embryo, a piece of thigh mesoderm is transplanted under the wing ectoderm.
(2½×4=10)
15. Answer these questions in brief.
i)
ii)
iii)
iv)
Describe the role of nerves in amphibian regeneration.
Draw a well labelled figure showing one complete reproductive / menstrual cycle, depicting
the interrelationship between hypothalamus, pituitary, ovaries and uterus.
Describe the process of oogenesis in mammals.
Define the term cleavage. Name and describe the types of eggs on the basis of presence
of yolk.
(2½×4)
16. Describe the various stages in development of cancer.
(5)
17. Describe the process of metamorphosis in urodeles.
(5)
18. Describe with the help of suitable diagrams the differentiation of retina in the development of
vertebrate eye.
(10)
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