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

What do you understand by hypelglycemia, Q. What do you understand by Hypel...

Q. What do you understand by Hypelglycemia? Hypelglycemia (abnormally high blood sugar): Maintenance of blood glucose levels within or close to the normal range has been stress

Define the purposes of counselling, Q. Define the Purposes of Counselling? ...

Q. Define the Purposes of Counselling? 1. Supporting individuals to take charge of their own life by: Providing information; Facilitating emotional adjustments; and

Protozoa, Characteristics Protozoa and examples

Characteristics Protozoa and examples

Pollutions, what is detergent pollution and it''s effects and causes

what is detergent pollution and it''s effects and causes

Explain rectangular full mucoperiosteal flaps, Explain Rectangular Full Muc...

Explain Rectangular Full Mucoperiosteal Flaps - Endodontic Surgery      a. Releasing and relaxing "vertical" incisions, with the Horizontal incision, b. Causes re

What were genotypes of the f2 plants crosses, A snapdragon plant that bred ...

A snapdragon plant that bred true for white petals was crossed to a plant that bred for purple petals, and all the F1 had white petals. The F1 was selfed. Among the F2, three other

Characteristics of river systems, Characteristics of River Systems Th...

Characteristics of River Systems The basic function of the rivers is to convey surplus rain water from land to sea. Annually the rivers carry fresh water, equivalent to 25 cm

Classification based on digestive fate of carbohydrates, Explain Classifica...

Explain Classification Based on Digestive Fate of Carbohydrates? The digestive fate of carbohydrates depends on their inherent chemical nature (monosaccharide composition and t

What phenotypic ratio you expect from such a cross, Assume that a dihybrid ...

Assume that a dihybrid cross (AaBb X AaBb) is made in which the gene loci are autosomal, independently assorting, and incompletely dominant. What phenotypic ratio would you expect

Plant, what is the scientific explanation of "touch me not" plant that can ...

what is the scientific explanation of "touch me not" plant that can react due to any touch

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