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

Role of nacl in metabolism, ROLE OF NaCl - It forms .9% of blood of ...

ROLE OF NaCl - It forms .9% of blood of mammal. It forms .7% of blood of frog. Bicarbonates of Na+ act as buffer for pH constancy. Involved in active transport of gluc

How many chromosomes and dna molecules found per cell, A cell in G1 of inte...

A cell in G1 of interphase has 12 chromosomes. How many chromosomes and DNA molecules will be found per cell when this original cell progresses to the G2?

Explain magnetic stirrer - food microbiology, Explain Magnetic Stirrer - Fo...

Explain Magnetic Stirrer - Food Microbiology It can be used for mixing ingredients at the time of media or reagents preparation. Mixing happens with spinning of a teflon coat

Fate of pyruvate, Pyruvate Pyruvate has three different  fates. Under a...

Pyruvate Pyruvate has three different  fates. Under aerobic conditions,  pyruvate enters mitochondriaand is converted to acetyl CoA. The acetyl CoA enters thecitric acid cycle.

What is pulse rate, Pulse Each time the left ventricle contracts and fo...

Pulse Each time the left ventricle contracts and forces blood into the aorta, it expands to adjust additional blood. And blood already present is pushed to other section and al

Express difference between chromosomes and chromatin, What is the differenc...

What is the difference between chromosomes and chromatin?

Define seminal plasma in human male, Seminal plasma in human males is rich ...

Seminal plasma in human males is rich in : 1. fructose and calcium 2. glucose and calcium 3. DNA and testosterone 4. ribose and potassium Fructose and Calcium

Post-mating isolating mechanisms, The second category of isolating mechanis...

The second category of isolating mechanism that may permit interspecific mating but ensures reduced viability is called post-mating isolating mechanism. This category could be subd

Agro industrial-enrichment of soil, Enrichment of soil Indirect provis...

Enrichment of soil Indirect provision of minerals to grazing livestock includes mineral fertilization of  pasture and altering soil pH, however this may not be always feasible

Explain the meaning of protein deficiency, Explain the Protein Deficiency? ...

Explain the Protein Deficiency? One of the most common nutritional disorders in the world today is the deficiency of protein. Both adults and children are affected, as the popu

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