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

Explain requirement for simple staining of bacterial culture, Explain Requi...

Explain Requirements for Simple Staining of Bacterial Cultures Culture: 24 hours bacterial culture of E. coli and Bacillus on nutrient agar or in broth. Reagents: Methylene

Types of hypertension, Types of hypertension are as follows: Essential ...

Types of hypertension are as follows: Essential Hypertension is called essential when no apparent cause is suspected or detected. This accounts for almost 90 per cent of pati

Signify the term metacoel, Signify the term Metacoel. The last of three...

Signify the term Metacoel. The last of three coelomic spaces found in tripartate body plan characteristic of deuterostome lineage of animals. Other coelomic compartments are th

Digestion, explain digestion in protozoans

explain digestion in protozoans

Porifera, what are the general characteristicss of porifera

what are the general characteristicss of porifera

Explain butylated hydroxyanisole, Butylated hydroxyanisole (BHA) It is ...

Butylated hydroxyanisole (BHA) It is commercially available as a mixture of two isomers and has found wide commercial use in the food industry. It is highly soluble in oil and

Explain cigrates smoking from lifestyle risk factors, Explain cigrates smok...

Explain cigrates smoking from lifestyle risk factors ? Smoking is the single most important preventable risk factor for CAD. There is strong evidence that smoking can significa

Epistasis, EPISTASIS Epistasis is the phenomenon of masking or suppress...

EPISTASIS Epistasis is the phenomenon of masking or suppressing the expression of a gene by another non allelic gene. The gene which suppresses the expression of a non allelic

Global alteration of brain functioning - sleep, Q. Global alteration of bra...

Q. Global alteration of brain functioning - Sleep? Sleep involves a global alteration of brain functioning, and occupies one third of our lives, The transition from waking to

What roles do membrane proteins play in transporting, What roles do membran...

What roles do membrane proteins play in transporting only certain substances into a cell? Some proteins form channels or pores by which certain substances can pass. Other pr

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