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

People who are at risk from drug-nutrient interactions, Determine People wh...

Determine People who are at risk from drug-nutrient interactions? People who are at risk from drug-nutrient interactions are the: 1. Persons who have a poor diet or in other

Define about aliphatic alcohols - non glyceride fractions, Define about Ali...

Define about Aliphatic alcohols - Non Glyceride Fractions? These are water-insoluble, with their content varying from 0.5-7% of the unsaponifiable matter. Rice bran oil contain

Statistical measures - population, Statistical Measures - Population A...

Statistical Measures - Population A population has a number of group characteristics that are statistical measures unique to the population group and are not the characteristi

Predict the outcome of future testing, A hypothesis can be used to predict ...

A hypothesis can be used to predict the outcome of future testing. Which type of hypothesis is easier to test? A. It is easier to specify and test for a difference between two outc

Embryology, Explain the gradient theoryof experimental embryology

Explain the gradient theoryof experimental embryology

Population, Population You must be familiar with the term 'population'. I...

Population You must be familiar with the term 'population'. It is one of the most talked about issues of this century. It is feared that the rapid growth of the world population

Discuss important factor of obesity, Discuss important factor of obesity ...

Discuss important factor of obesity Weight is a most important factor for identifying obesity. Weight is measured in kilograms (kg). It is measured during the first visit and n

What is pulmonary veins in normal pulmonary vasculature, Q. What is Pulmona...

Q. What is Pulmonary Veins in Normal Pulmonary Vasculature? The right and left upper lobe or superior pulmonary veins descend lateral to the arteries, cross in front of the hil

What is the functional unity of the kidneys, Q. What is the functional unit...

Q. What is the functional unity of the kidneys? The functional (filtering) unity of the kidneys is the nephron a nephron is made of efferent arteriole, afferent arteriole, glom

Signs and symptoms of emphysema, Pathophysiology Distension and damage...

Pathophysiology Distension and damage of the respiratory bronchioles selectively occur. Opening develops in the walls of the bronchioles. and they become enlarged and conf

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