Central cell - synergids, Biology

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.

Posted Date: 1/23/2013 2:01:22 AM | Location : United States







Related Discussions:- Central cell - synergids, Assignment Help, Ask Question on Central cell - synergids, Get Answer, Expert's Help, Central cell - synergids Discussions

Write discussion on Central cell - synergids
Your posts are moderated
Related Questions
Define Mobilization of bone calcium and phosphorous? It is now firmly established that vitamin D 3 is metabloized first in the liver to 25-hydroxyvitamin D (25 OH- D) (calcicl

Q. Explain about Gastric ulcers? Gastric ulcers occur in the lesser curvature of the antrum of stomach. A gastric ulcer appears to be caused by reflux of bile and factors that

List the four phases of mitosis, and briefly explain what occurs during each phase. Prophase: the chromatin coils and produces chromosomes, the nucleolus and nuclear envelope d

The lower course - Classification of the river The lower course of the river occurs in the plains, across which it meanders or zigzags slowly. The river here loses much of its

The complications that occur in the heart due to hypertension are left ventricular hypertrophy, diastolic dysfunction and cardiac failure. There is also associated coronary artery

While waiting at an airport , nail Campbell once overheard this claim, its paranoid and ignorant to worry about industry or agriculture contaminating the environment with chemical

Question 1 A patient is admitted to the hospital with suspected pneumococcal pneumonia. How would you confirm this initial diagnosis? Answer the following questions a) Which is

How are ecological interactions classified? Ecological interactions are divided as intraspecific or interspecific interactions and as harmonious or inharmonious interactions.

Q. How to investigate aortic stenosis by Roentgenogram? Cardiac enlargement does not occur in pure compensated aortic stenosis. Post stenotic dilatation of aorta may be seen. F

Palpate the radial or brachial artery pulsation while inflating the cuff to a level of 30 mm Hg above the point at which the brachial or radial artery pulsation disappears. Reinfla