No. of Printed Pages: 12 ILSE-061
BACHELOR OF SCIENOE (B.Sc.)
Term-End Examination
2016

02676
LIFE SCIENCE LSE-06 DEVELOPMENTAL BIOLOGY
Time: 2 hours Maximum Marks: 50
Note: An$wer Part 1 and Part 11 ;in separate answer copies. Answer the questions as per instructions given in e,ach Draw well-labelled diagrams, wherever necessary.
PART I (PlantDevelopment)

Note: Question no. 1 is compulsory. Attempt any four questions from questiron,s no. 2 to 7.

1. Fill in the blanks 3

is the anther wall layer that helps in the dehiscence of anther.

Degenerated cell of embryo sac is the seat for pollen tube discharge.

fibres develop from the phloem tissues in the stems of plants.

Orbicules are generally absent in type of tapetum.

is a hormone associated with fruit ripening.

The technique of culture helps to raise virus-free plants.

Write the appropriate technical term for the following: 2

An outgrowth of placenta or funiculus that directs the pollen tube to micropyle

A group of pollen grains that occur in a mass

The stigmas that secrete exudates

In vitro production of plants from pollen grains

2. Write short notes on any two of the following: 5

Tapetum

Seed dormancy

Polyembryony

Suspension culture

3. Write down three important differences between any two of the following: 5

Egg cell and Synergid cell

Entomophily and Anemophily

Intine and Exine

Vascular cambium and Cork cambium

4. What is sexual incompatibility What is its biological significance Describe any two methods to overcome sexual incompatibility. 5

5. Auxins, in association with cytokinins and ethylene play a role. in controlling apical dominance. Explain. 5

6. What is clonal-or micro-propagation? Describe its applications in agriculture and horticulture. 5

7. Answer any two of the following:

What is endosperm What are its functions?

Describe anyone type of aberrant secondary growth due to abnormal cambial activity in a plant.

Briefly discuss the production of industrial compounds through plant tissue culture.


PART II

(Animal Development)

Note: Question no; 8 is compulsory. Attempt any four questions from questions no. 9 to 14.

8. Fill in the blanks. 6x

refers to formation of sperm cells in male gonads.

The early response for the entry of sperm into the egg is the prevention of .

The movements of cells in the embryo to establish diverse organs and tissues are called movements.

The stimulation of population of cells to differentiate in a specific direction by another group of cells is called .

The metamorphic changes which bring about retention of certain larval structures in the adult are called changes.

The ability of the malignant cell to detach itself from the tumour and establish a tumour on another site is called .

Differentiate between the following pairs: 2

Microlecithal and Mesolecithal eggs

Animal pole and Vegetal pole

9. What do you understand by cell determination? 1

Differentiate between mosaic and regulative embryos. 4

10. Describe the acrosomal reaction in mammals leadingto fertilisation. 5

11. What do you understand by the term cleavage? Briefly explain the difference between holoblastic and meroblastic cleavages.

12. What are the characteristic features of avian gastrulation Diagrammatically show the formation of primitive streak in the chick embryo. 5

13. Explain the sequence of events in the urodele limb regeneration. 5

14. Write short notes on any two of the following: 2x2

Role of hormones in human aging

Incomplete metamorphosis in insects

Fate of germ layers in humans

The mechanisms known to convert proto-oncogenes to oncogenes