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

Calorie requirements for ulcerative colitis, Q. Calorie requirements for ul...

Q. Calorie requirements for ulcerative colitis? Energy: The calorie requirements must be increased to: 1) Restore weight status and maintain ideal weight. 2) Compensate f

What is motor neuropathy, What is Motor Neuropathy It leads to muscular...

What is Motor Neuropathy It leads to muscular weakness and wasting.  Muscle wasting leads to various foot deformities and abnormal pressure points develop due to loss of even p

What are biotic factors, What are biotic factors? The Biotic factors ar...

What are biotic factors? The Biotic factors are living beings (plants, microorganisms and animals) that are part of a given environment.

Protozoa., brief account on classification and general characters of protoz...

brief account on classification and general characters of protozoa

Shapes - types of nursing units, Shapes: Nightingale Ward  In the 1...

Shapes: Nightingale Ward  In the 1940s,  this traditional nursing unit was based on  the long rectangle pavilion type ward and self-contained unit. This concept is establis

Explain structural and functional relationship, Describe the location and s...

Describe the location and structure of the pituitary gland and explain its structural and functional relationships with the hypothalamus.

Explain the impedance method to measure body fats, Explain the Impedance me...

Explain the Impedance method to Measure Body Fats? Impedance method: This method can give entire body composition like total body water (TBW), fat free mass (FFM) or lean body

Various modalities available for sterility assurance, Q. Enlist the various...

Q. Enlist the various modalities available for sterility assurance? Various modalities available for sterility assurance are a) Prevention of overloading b) Chemical indi

What is genomics , We are living in an unprecedented age of biological ...

We are living in an unprecedented age of biological discovery and the application of biological knowledge.   Programmed DNA sequencing delivered, in the year of  2001 over the 2.6

Explain the endosperm of angiosperms, How different are the endosperm of gy...

How different are the endosperm of gymnosperms and the endosperm of angiosperms? In gymnosperms the endosperm is haploid (n), it is known as primary endosperm. In angiosperm th

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