Central cell - synergids, Biology

Assignment Help:

Central Cell - Synergids

It is the largest cell of the embryo sac, and the mother cell of the endosperm. The enlargement of the embryo sac after the last nuclear division is mainly due to the inflation of the large central vacuole of the central cell. The vacuole in the central cell is presumably the reservoir of sugars, amino acids and inorganic salts. The nuclei of the central cell, also called the polar nuclei, are very large, and are characterized by a conspicuous nucleolus. They are present either in the centre of the cell, suspended by cytoplasmic strands, or in the cytoplasm close to the egg apparatus. In the latter case the chalazal portion of the embryo sac is occupied by a large vacuole. The two polar nuclei fuse before or during double fertilization to form the secondary nucleus.

The cytoplasm of the central cell is rich in plastids, mitochondria, numerous, dictyosomes, and ribosomes or small polysomes. This cell appears to be the centre of intensive synthetic activity in the embryo sac. The thickness of the central cell wall is variable. It is thickest in the regions in contact with the nucellus. Where the central cell touches the egg and synergids, it shows the common feature of partial wall. It becomes thinner towards the chalazal end of the egg apparatus, and finally, in the chalazal region there is no wall between the plasma membranes of the central cell and those of the egg and the synergids. The central cell is connected along with the.egg, synergids, and the antipodals through plasmodesmata connections.


Related Discussions:- Central cell - synergids

Define larval stage of taenia cystcercus, Define Larval Stage of Taenia Cys...

Define Larval Stage of Taenia Cystcercus? The pork tapeworn (T: solium) and beef tapeworn (T : saginata , which are endoparasites of humans who are the final hosts

Glycogen, G L YCOGEN Polymer of a-D-glucose. It has 5000-30000 uni...

G L YCOGEN Polymer of a-D-glucose. It has 5000-30000 units of a-D-glucose. Glycogen is glucosan homopolysaccharide which is the major reserve food of animals, fungi and

Conducting system of the heart, The fibrous rings of the four valves of the...

The fibrous rings of the four valves of the heart are continuous with each other. They not only form the basis for the attachment of the corresponding valve cusps but also form an

What is respiratory system explain their functionality , What is Respirator...

What is Respiratory System explain their functionality ? The respiratory system is responsible for the transport of oxygen and carbon dioxide from outside the body to and from

State the strengths of brief screening measures, Strengths of Brief Screeni...

Strengths of Brief Screening Measures 1) Inexpensive, rapid, portable 2) Needs less training in administration and interpretation 3) Differentiating between dementia and

Enumerate different implant materials, Q. Enumerate different implant mater...

Q. Enumerate different implant materials? Biomaterials fall into four categories: metal and metal alloys, ceramics (carbon included in this group) synthetic polymers, and natur

Determine the term - chlorine, Determine the term - Chlorine   The appl...

Determine the term - Chlorine   The application of chlorides results in leaves of greater spread, a lighter green colour and with a smoother surface. However, the combustibilit

Mycotic aneurysms, They result from septic embolization of vegetations to t...

They result from septic embolization of vegetations to the arterial vasa vasorum or the intraluminal space, with subsequent spread of infection through the intima and outward throu

Which of following is not true regarding the immune response, Which of the ...

Which of the following is not true regarding the immune response? Answer The immune response uses chemical and phagocytic cells to destroy foreign cells. Once initiated, the immune

Animal kingdom, i need information about speen of animals and stuff like th...

i need information about speen of animals and stuff like that for example a cheetah speed

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd