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

Maggiolo, In 1809, Maggiolo described a process of fabricating and insertin...

In 1809, Maggiolo described a process of fabricating and inserting gold roots into freshly extracted sockets. The implant was constructed from the three pieces of gold which were s

Define initiation phase - mechanism of protein synthesis, Define Initiation...

Define Initiation phase - mechanism of protein synthesis ? The assembly of a ribosome on an mRNA molecule at the correct start point, the initiation codon. Three initiation fac

Determine some beneficial effects of phytates, Determine some Beneficial ef...

Determine some Beneficial effects of phytates? Some of the health promotive aspects of phytates include: 1) Phytic acid is a known antioxidant. Colonic bacteria produce oxyg

Explain isozymes, ISOZYMES Sometimes an  enzyme present  in  the  same ...

ISOZYMES Sometimes an  enzyme present  in  the  same  organism is  found  to  have different molecular forms but  catalyzing the  same  reaction. These are called  isozymes. Th

What is cellular respiration, What is Cellular Respiration? Cellular R...

What is Cellular Respiration? Cellular Respiration : The most important of the metabolic processes, cellular respiration, provides energy for most chemical reactions in an or

What are the so-called good and bad cholesterol, What are the so-called "go...

What are the so-called "good" and "bad" cholesterol? Lipoproteins are complexes made of lipids (triglycerides and cholesterol) and proteins. The lipoproteins present dissimilar

Seismic waves, Earthquake creates seismic waves that travel through and aro...

Earthquake creates seismic waves that travel through and around the surface of the earth. Seismic waves are the waves of energy caused by sudden breaking of rocks during an earthqu

Explain about the color vision of human eye, Explain about the Color vision...

Explain about the Color vision of human eye The human eye can see about 150 different colours in the visible spectrum (400- 750 nm). Red, green and blue are said to be the prim

How many layers in retina, How many Layers in retina The retina is comp...

How many Layers in retina The retina is composed of  ten  layers: a:)  Pigmented epithelium (outermost layer), b)  Neusoepithelium, rods and cones  (photoreceptors), c

Explain the nutritional and functional role of magnesium, Minerals :- Magne...

Minerals :- Magnesium    Food Source      Whole grains, nuts, legumes, green leafy vegetables Nutritional Functional role Essential nutrient: Deficiency is rare Co

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