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 haemagglutinins, Q. What do you understand by Hae...

Q. What do you understand by Haemagglutinins? Haemagglutinins are the globulin type of proteins which are present in the seeds of plants like double bean, field bean, white be

Types of neurons, TYPE S OF NEURONS - The neurons are classified on th...

TYPE S OF NEURONS - The neurons are classified on the basis of their structure and function. (A) On the basis of the structure, the neurons are of four types.

What best describes the amoebas division, What best describes the amoebas d...

What best describes the amoebas division?  (1) It is a Mode of asexual account in which a one parent is involved. The amoeba cell, which is unicellular, separates into two daug

Psychosocial therapy, PSYCHOSOCIAL THERAPY: Psychosocial therapy is on...

PSYCHOSOCIAL THERAPY: Psychosocial therapy is one of  the important treatment modaIities used for the patients with mental disorders. It is given along with other therapies or

Precautions to prevent from hiv , Precautions to prevent from HIV  To a...

Precautions to prevent from HIV  To avoid HIV infection one should practice safe sex (use of condoms). Besides a few simple precautions are given for protection against HIV inf

Origin of endoplasmic reticulum, ORIGIN OF E.R. (1 )      Originates...

ORIGIN OF E.R. (1 )      Originates from plasma membrane. (2 )      According to Haguenau, E.R.originates from Nebenkern (Germ center). Nebenkern is a group of conce

Poultry and duck diseases-duck plague, Duck plague Duck plague, caused ...

Duck plague Duck plague, caused by a member of Herpesviridae, has world wide distribution and occurs among domestic and wild ducks, geese, swans and waterfowls. Epidemiolo

Counselling of pace programme, Q. Counselling of PACE programme? Counse...

Q. Counselling of PACE programme? Counselling is a key component of a PACE programme. Counselling is a process that enables a person to identify problems and find a solution or

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