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

Avian infectious bronchitis (ib), A v i a n infectious bronchitis (IB) ...

A v i a n infectious bronchitis (IB) An acute, highly contagious respiratory disease of chicken caused by a member of the family Coronaviridae, IB was first recognized in I

Microbiology and parasitology, Describe the methods that are used for the i...

Describe the methods that are used for the isolation and identification of bacteria.(20 marks)

What is the permeability to sodium ions, An impermeable membrane separates ...

An impermeable membrane separates a one liter solution of 1M NaCl in the left compartment from a one liter solution of 2M KCl in the right compartment.  At 2 AM the membrane became

Nutrition affecting the growth of microorganism, Q. Can Nutrition affecting...

Q. Can Nutrition affecting the growth of microorganism? Ans. Food is food to humans and microbes - be it carbohydrates, proteins or fats. The nutritional requirements of b

What are the major functions of fruits, What are the major functions of fru...

What are the major functions of fruits? The major functions of fruits are the protection and spreading of seeds.

When does the greatest buffering capacity of weak acids, The greatest buffe...

The greatest buffering capacity of weak acids is when- Select one: a. They are almost completely dissociated b. They are almost completely undissociated c. They are nea

Explain tertiary butylhydroquinone, Tertiary Butylhydroquinone (TBHQ) T...

Tertiary Butylhydroquinone (TBHQ) TBHQ is moderately soluble in oil and slightly soluble in water. In many cases, TBHQ is more effective than any other antioxidant in providing

Synthesis of citratefrom acetyl coa and oxaloacetate, Synthesis of citratef...

Synthesis of citratefrom acetyl CoA and oxaloacetate: Citrate synthase catalyses this aldol condensation reaction with the release of CoA. There are certain inhibitors to  this re

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