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

Taxonomy, classification tree for pisces

classification tree for pisces

What is an illustration of gene control, Q. What is an illustration of gene...

Q. What is an illustration of gene control? An elegant instance of gene control in bacteria is operon system. A cluster of genes which is responsible for synthesizing a particu

Explain about the term- therapeutic, Explain about the term- Therapeutic ...

Explain about the term- Therapeutic Therapeutic approaches that scientists are pursuing include transplanting cells to replace those which are damaged or using growth factors

Principle for presence of vanaspati and rancidity in ghee, Principle for Pr...

Principle for Presence of Vanaspati and Rancidity in Ghee Cheap edible and nonedible oils like argemone oil, white oil, tea seed oil etc. are used as adulterants in more expens

Define carcinogenic - dietary factors, Define Carcinogenic - Dietary Factor...

Define Carcinogenic - Dietary Factors? Dietary constituents can also be carcinogenic. But to what extent diet is one of the contributing factors to cancer development is not kn

Explain about the chytridiomycota - fungi, Explain about the Chytridiomycot...

Explain about the Chytridiomycota - Fungi Chytridiomycota - Look at the Figure, which illustrates chytridiomycota. These are the simplest among true fungi and are commonly call

Why is the fish circulation classified as simple circulation, Why is the fi...

Why is the fish circulation classified as a simple and complete circulation? Complete circulation is that in which there is no mixture of venous blood and arterial blood. As ci

What is the energy efficiency of photosynthesis, What is the energy efficie...

What is the energy efficiency of photosynthesis? a) What area is occupied by each molecule? b) Calculate the molecular absorption cross section in units of A 2   A cr

Determine the evaluation of the bone, Evaluation of the bone Evaluation...

Evaluation of the bone Evaluation of the bone -implant interface needs to be done by the following: Failures in Implant Dentistry 1) Implant mobility and discomfort 2)

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