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ASSIGNMENT BOOKLET
ASSIGNMENT BOOKLET
Bachelor Degree Programme in Science
Application
Oriented Course
(B.Sc.)
In
Human Environment
Bachelor’s Degree Programme
Elective Course
in
Developmental Biology
ASSIGNMENTS
2005
ASSIGNMENTS
2005-6
ASSIGNMENT 1 –TMA
TMA 1
ASSIGNMENT-1
ASSIGNMENT
2
–
TMA 2
ASSIGNMENT-2 TMA
ASSIGNMENT 3 – TMA 3
Dear Students,
SCHOOL
OF SCIENCES
Assignments
1, 2 and 3
Indira Gandhi National
2005Open University
Maidan Garhi
New Delhi – 110 068
1
LSE-06
LSE-06
Assignments 1 and 2
2005-6
Dear Students,
As explained in the Programme Guide, you will have to do 2 assignments for the elective course in
Developmental Biology (Course Code: LSE-06). Both the Assignments are Tutor Marked (TMA).
The instructions for doing the assignments are given in the Programme Guide under the Section 7.1
Assignment. Read the instructions carefully before you start to work on the assignments.
Please submit your assignments as follows:
Assignment No.
Date of Submission
Where to Send
Assignment – 1 (TMA)
8 weeks after receiving the printed
material with assignments.
The Coordinator of your study centre.
Assignment – 2 (TMA)
12 weeks after receiving the printed
material with assignments.
The Coordinator of your study center
Answer sheets received after the due date shall not be accepted.
We strongly suggest that you retain a copy of your assignments.
Wishing you all good luck.
2
ASSIGNMENT-1
(Tutor Marked Assignment)
Course Code: LSE-06
Assignment Code: LSE-06/TMA-1/ 2005-6
Maximum Marks: 100
1.
Present similarities between microsporogenesis and megasporogenesis.
2.
Indicate the ploidy levels in the cells of following origin: epidermis, endothecium, middle layers,
tapetum, and microspores.
(2½)
Match the items of Column A with those of Column B.
(2½)
3.
i)
ii)
iii)
iv)
v)
A
Hypodermal archesporial cell
Pollen kitt material
Integumentary tapetum
Persistent nucellus
Fibrous bands of cellulose and pectin
a)
b)
c)
d)
e)
(5)
B
Endothelium
Endothecium
Perisperm
Periplasmodium
Tenuinucellate ovule
4.
In the event of complete consumption of nucellus in the initial stages of development of embryo sac
how the nutrition for subsequent development is ensured? Discuss.
(2)
5.
Explain how a coenomegaspore is formed?
(2)
6.
What kind of pollen sterility is important for plant breeding?
(1)
7.
Differentiate between the following terms:
i)
ii)
iii)
iv)
8.
Pollinium and massulae
Gametophyte-determined and sporophyte-determined male sterility in angiosperms
Features of exine and intine
Vegetative and generative cell
(2×4)
Fill in the blank spaces with appropriate words:
i) ……………………. pollination over several generations results in weaker progeny.
ii) ……………………. flowers accomplish fertilization without exposing their sex organs to the
atmosphere.
iii) In ………………… self incompatible systems rejection reaction is faster than in ………………..
self incompatible systems.
iv) The type of reproduction wherein unfertilized egg develops into an embryo without sexual
fusion is referred to as …………………………. .
(5)
9.
Write brief answers to the following questions:
i)
ii)
iii)
iv)
v)
What are the prime requirements of pollination?
What factors cause the adhesion of pollen on stigma?
What determines the path of pollen tube beyond the stigma?
Bud pollination is used to overcome self incompatibility. Mention its logic.
What is the ecological significance of apomixis?
3
(1)
(2)
(1)
(1)
(2)
10.
Draw labelled diagrams and give one characteristic feature of each the following types of
endosperms:
i) Nuclear type
ii) Cellular type
iii) Helobial type
(2×3)
11.
Describe the functions of endosperm.
(2)
12.
On what basis is embryogeny classified into six major types? Describe their types.
(2)
13.
What is polyembryony? Describe the important types of polyembryony in flowering plants and
give their importance.
(3)
Define seed appendages, give their types and also show how these seed appendages help in seed
dispersal.
(2)
14.
15. Write short notes on the following:
i)
ii)
iii)
iv)
Biochemical changes during metamorphosis of frog.
Superficial cleavage in insects.
Capacitating of sperms in mammals.
Neoteny
(2½4)
16. Answer the following briefly.
i)
ii)
iii)
iv)
v)
What are the various cell layers produced from the inner cell mass of the mammalian embryo?
Name the three zones from the inner to the outer side of neural retina.
List the secondary egg envelopes in chick.
What happens when only the eyes of planaria are removed without affecting the brain?
What happens when a baby is born to a mother infected with Rubella virus during the first 4-5
weeks of pregnancy?
(35)
17. Fill in the blanks.
i)
ii)
iii)
iv)
v)
The regular replacement of erythrocytes in vertebrates is an example of ……………….. regeneration.
The interval between two moults of an insect larva is called ……………………..
One of the causes of aging is the formation of ……………… ……………….. in the cells.
Presumptive mesodermal and endodermal cells migrate from the external surface of the embryo into its
interior by the process of …………………..
The modifications of the structure of blastula are related to the amount of ……………………..
Present.
(15)
18. Answer in not more than 500 words.
i)
ii)
Discuss the contribution of thyroid gland in the process of amphibian metamorphosis.
Outline the stages of carcinogenesis.
(25)
19. With the help of suitable diagrams describe the process of neurulation in frog. How does it differ from
neurulation in chick?
(10)
4
ASSIGNMENT-2
(Tutor Marked Assignment)
Course Code: LSE-06
Assignment Code: LSE-06/TMA-2/ 2005-6
Maximum Marks: 100
1.
Describe secondary growth of a typical dicotyledonous stem with properly labelled diagrams.
(5)
2.
Discuss the major molecular events and morphological changes that follow floral induction.
(5)
3.
Select the right answers for the following:
i)
(1×5)
Lateral roots develop from:
a)
b)
c)
d)
epidermal cells of root
root meristem
cortex of root
inner tissues of root
ii) The geotropic response of roots is mediated by:
a)
b)
c)
d)
phytochrome
abscisic acid
auxins and ethylene
light stimulus
iii) The arrangement of egg cell, synergids and antipodals in an embryo sac demonstrate:
a)
b)
c)
d)
Fibonacci sequence
polarity
totipotency
endogenous rhythms
iv) Select the right choice amongst the words given in parenthesis:
The role of (auxins/ethylene) is found in the bending of coleoptiles of dark grown seedlings of
Avena towards light.
v) Quiescent center is unique to which one of the following?
a)
b)
c)
d)
4.
i)
Root apex
Shoot apex
Leaf primordia
Floral apex
“Seed dormancy is critically important for the survival of plants”. Discuss this statement in the
light of various factors involved.
(5)
ii) What events mark the state of dormancy in plants?
5.
(2½)
Write short notes on the following:
i) Synergistic and sequential effects of hormones.
ii) Plant growth regulators involved in apical dominance.
5
(2½×2)
6.
State whether the following statements are true or false.
i)
ii)
iii)
iv)
v)
7.
The various events in fruit ripening are mediated through activation or de novo synthesis
of a number of enzymes.
The plant growth regulators do not have any role in natural senescence.
Auxins play an active role in leaf abscission.
The plant growth regulators exhibit two levels of responses: rapid responses and long term
responses.
Parthenocarpy is promoted by auxins.
Prepare a detailed account on apical dominance pertaining to the following aspects:
i) the controlling factors,
ii) its eco-physiological significance, and
iii) applications in horticulture and agriculture.
8.
(½×5)
(2½×3)
Match the items given in A with those of B and select the correct answer from the choices (a-d)
given below:
A
i) A piece of tissue to start a culture
ii) Harvesting bioorganic compounds
iii) Multiple genetically identical copies
of selected cells/tissues/plants
iv) Applied to sexually incompatible crosses
v) In-vitro gynogenesis
A
B
l) Cloning
m) Embryo culture
n) Bioreactors
o) Haploid production
p) Explants
i
ii
iii
iv
v
a
m
n
l
o
p
b
o
p
n
m
l
c
p
n
l
m
o
d
l
m
o
p
n
Choices 
(2½)
9.
i)
Describe the method of raising virus-free plants from virus-infected plants. Enhance the
clarity of your answer by making diagrams.
ii) Discuss how the tissue culture techniques can be employed in the conservation of plants?
10.
11.
Prepare a detailed account on the male gametophyte in higher plants including the recent
advancements in its knowledge. Hint: Prepare your answer based on your understanding of
the male gametophyte studied in Units 2 and 12.
(2½)
(2½)
(5)
Define the following
i)
ii)
iii)
iv)
v)
Ooplasmic determinants
Embryonic induction
Imaginal discs
Zona reaction
Graafian follicle
(25)
6
12.
What is genomic equivalence of nuclei of cells? Describe one experiment that proves the
hypothesis.
(10)
or
Describe Gurdon’s experiments on nuclear transplantation that test the potency of embryonic nuclei.
13.
Draw the structures of the mammalian eye and describe its development from the optic vesicles.
14.
Differentiate between the following:
i)
ii)
iii)
iv)
15.
Intrinsic and extrincic growth factors
Foetal and embryonic development
Oncogenes and protooncogenes
Blastula and blastocyst
(5+5)
(42½)
What happens when:
i) Half of the limb field in Ambystoma at the tail bud stage is removed and grafted at a different site.
ii) The wing mesoderm of early stage embryo of chick is isolated, rotated by 180º and transplanted in
another embryo of the same stage.
iii) Limb bud ectoderm is grafted at a non limb site in chick embryo.
iv) When limb mesoderm is removed from under the ectoderm of limb area or replaced by mesoderm from
non limb area in chick embryo.
v) Limb mesoderm is grafted under ectoderm of any region of an early chick embryo.
(52)
7