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

Describe the various types of rna, Describe the various types of RNA? ...

Describe the various types of RNA? Types of RNA :  There are three different types of RNA, all formed by transcription from DNA: (1) Messenger RNA (mRNA) is a single unc

Study of tonana larva, Study of tonana larva Tornaria larva is typical...

Study of tonana larva Tornaria larva is typical in the life-history of hemichordates. Examine the permanent slide and note the following features: I. The tornaria larva usu

What are respiratory pigments, Q. What are respiratory pigments? What is th...

Q. What are respiratory pigments? What is the respiratory pigment present in some arthropods? Which is the analogous molecule in humans? Respiratory pigments are molecules able

Explain trifluridine, Explain Trifluridine  (Viroptic)  Trifluridine is...

Explain Trifluridine  (Viroptic)  Trifluridine is a nucleoside analog active against herpes viruses, including acyclovir-resistant strains. Marketed in an ophthalmic preparatio

What are the preservation of insulin, What are the Preservation of Insulin ...

What are the Preservation of Insulin Regular insulin is stable for 18 months at 23.8 0 C and Lente insulin are stable for 24 months at this temperature. Although refrigeration

Meaning of cellular secretion, Cell secretion is the elimination to the ext...

Cell secretion is the elimination to the exterior of substances formed by the cell (for example, hormones, mucous, sweat, etc.)

Illustrate the term - digestive caecum., Illustrate the term - Digestive ca...

Illustrate the term - Digestive caecum. A blind-ended pouch which extends from main digestive tract. Digestive ceca may be the sites for final digestion of ingested food or may

Botany., the evolution of gamatophyte in pteridophyte

the evolution of gamatophyte in pteridophyte

Biology in ancient india, BIOLOGY IN ANCIENT INDIA - L A T E STONE ...

BIOLOGY IN ANCIENT INDIA - L A T E STONE AGE [10,000 - 20, 000 B.C) Man first cultivated wheat, barley, lentils & peas. In India rice was first cultivated at Meherga

Explain eicosanoids, Explain Eicosanoids Eicosanoids are the  local h...

Explain Eicosanoids Eicosanoids are the  local hormones formed  by  body  tissues during self-healing responses  to  stimuli.  Eicosanoids are  a family  of  compounds  deriv

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