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

What anatomical direction with respect to occipital cortex, The frontal cor...

The frontal cortex is in what anatomical direction with respect to the occipital cortex? a. anterior b. posterior c. sagittal d. inferior

Explain understanding the response of farmers, Explain Understanding the re...

Explain Understanding the response of farmers? Understanding the response of the farmers by the government also influences the food production. Government policy influences the

Applications of closed heart surgery, Applications :  The first operation ...

Applications :  The first operation conducted was ligation of a patent ductus arteriosus through a left thoracotomy. Same approach is used for repair of coarctation of the aorta,

What is the general function of leukocytes, Q. What is the general function...

Q. What is the general function of leukocytes? What are leukopenia and leukocytosis? The general function of leukocytes is to participate in the made inside the body or defense

Post-operative care of teeth, Post-operative care of teeth After implan...

Post-operative care of teeth After implant surgery, patients should be warned to expect:  Some swelling and possibly bruising.  Some discomfort which can usually be contr

Explain disorders of the gastrointestinal tract, Q. Explain Disorders of th...

Q. Explain Disorders of the gastrointestinal tract? The diseases and disorders of the gastrointestinal (GI) tract. Have you ever suffered from abnormal symptoms of the gastroin

Arteries - circulation, Arteries - Circulation The arteries deliver bl...

Arteries - Circulation The arteries deliver blood from the heart. Figure shows the structure of arteries and the different layers of the vessel wall. The thick walls of these

Define methods for determining amount of microbes in food, Define Methods f...

Define Methods for Determining the Amount of Microbes in Food? Following methods can be employed for determining the amount of microbes in the food samples and analyzing their

Conservation of biodiversity, Conservation of biodiversity is very importan...

Conservation of biodiversity is very important to maintain the ecological balance of ecosystem. Various steps for conservation of biodiversity: 1.           Creation of consc

Acute aortic regurgitation-types of regurgitation, Acute Aortic Regurgitati...

Acute Aortic Regurgitation :  The most dramatic presentation occurs in dissection of the aortic root. Endocarditis of the native or prosthetic aortic valve may also lead to a

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