Q. 145.0( 1 Vote )

The embryo sac in

Answer :

A matured embryo sac contains an egg apparatus, antipodal cells and central cell.

Egg apparatus


located in the micropylar end


Constitute three cells which are grouped together.


They are two synergids and one egg cell.


Synergids guide the entry of pollen tube. It has a special cellular thickening at the micropylar tip called filiform apparatus.


An egg cell has the female gamete.


Antipodal cells


Three cells in the chalazal end are the antipodal cells.


Central cell


It is a large cell


Central cell constitutes two polar nuclei.



Hence a total of 7 celled (3 antipodal cells, one central cell, 2 synergids, 1 egg cell) and 8 nucleate (3 antipodal nuclei, 2 polar nuclei, 2 synergids nuclei, 1 female gamete nuclei) makes the nature of female gametophyte.


OR


In angiosperms, the seed is the final product of sexual reproduction. It is often described as a fertilized ovule.


seed.jpg


Steps involved in the maturation of an ovule into a seed:


• Integuments of the ovule harden as tough to produce protective seed coats.


• Micropyle remains as a small pore in the seed coat. It facilitates the entry of oxygen and water into seed during germination.


• As seed matures, the water content is reduced and become relatively dry.


• The metabolic activities of the embryo slow down.


• Embry enters into a state of inactivity called dormancy.


• Germination on availability of favourable conditions (adequate moisture, oxygen and suitable temperature).


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :

In the given diagBiology - Exemplar

Vivipary automatiBiology - Exemplar

(a) Trace tBiology - Board Papers

List the changes Biology - Exemplar