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

Haccp - what is validation, HACCP - What is Validation Validation   : ...

HACCP - What is Validation Validation   :  That element of verification focused on collecting and evaluating scientific and technical information to determine  if  the HACCP

Treatment of hypertension, Elderly Is the treatment of hypertension di...

Elderly Is the treatment of hypertension different in elderly? Generally, the target for treatment should be at lower levels in the elderly. This is because, the elderly have

Nitrogen fixation, Nitrogen Fixation Nitrogen is an essential constitue...

Nitrogen Fixation Nitrogen is an essential constituent of living organisms and there is an inexhaustible supply of it in the atmosphere in the free form. Majority of living o

Give the introduction to evaluation of patient clinical, Give the introduct...

Give the introduction to evaluation of patient clinical examination ? A careful physical examinations is a very important for assessing the cardiovascular system and after prov

Genetic, 1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) a...

1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) are all found on the X-chromosome of Drosophila melanogaster. All of these are recessive traits. They map in the or

Transport through plasma membrane, TRANSPOR T THROUGH P.M. P.M. regula...

TRANSPOR T THROUGH P.M. P.M. regulates transport of materials in and outside of cell P.M. is semi- permeable as it allows rapid passage to water molecules. P.M. is selectively

Electronic chip is implanted in the body – vivo and vivo, An electronic chi...

An electronic chip is to be implanted in the body. During in vitro (in the lab) testing it is observed that the chip will dissolve over time if exposed to liquid with similar pH to

What does acute disease mean, What does acute disease mean? An sharp di...

What does acute disease mean? An sharp disease is which does not last for a longer duration n has no weakness in the body

Drinking & driving, DRINKING & DRIVING - It should not be mixed because...

DRINKING & DRIVING - It should not be mixed because alcohol - 1.       Impairs ability to judge distances. 2.       Reduces capacity to coordinate limb muscles. 3.

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