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 a health issue or disease, Describe a health issue or disease and ...

Describe a health issue or disease and recommend an intervention (you may utilize the health issue . Justify the intervention level (primary, secondary and tertiary) and setting ch

Where can rna are found within cells, In the eukaryote cell nucleus, RNA ca...

In the eukaryote cell nucleus, RNA can be found dispersed in the nuclear fluid, along with DNA, and as the major constituent of the nucleolus. In cytosol (in eukaryotes or in bacte

Explain the lamarcks theory in evolution, Explain the Lamarck's Theory in e...

Explain the Lamarck's Theory in evolution? Prior to Darwin, most people believed in and held to the creationist viewpoint that species were created in their current forms, whic

Explain the mitotic prophase, Which of the following best explains what wou...

Which of the following best explains what would happen if recombination (crossing-over) happens during mitotic prophase? A. Recombination during mitosis will lead to segregatio

Structures shared by every chordate, Q What are the three structures shared...

Q What are the three structures shared by every chordate that characterize the group? All beings of the phylum Chordata have branchial clefts in the pharynx in some species pre

Characteristics of the digestive system of earthworm, Q Which are the organ...

Q Which are the organs and characteristics of the digestive system of earthworms related to the kind of diet of these animals? Small organisms ingested together with soil parti

Stable atoms have no vacancies in their outer shell, Select all that are tr...

Select all that are true/correct: Stable atoms have no vacancies in their outer shell. Hydrogen is more stable than carbon Helium is more stable than carbon Helium is more stable t

Foot-rot, Foot-rot Foot-rot is a term applied to the condition of feet ...

Foot-rot Foot-rot is a term applied to the condition of feet of cattle, sheep, goats and sometimes pigs. It is characterized by inflammation, necrosis and ulceration of underly

Define about the resistant starch, Define about the Resistant Starch? U...

Define about the Resistant Starch? Until 1980's starch was thought to be completely hydrolyzed and absorbed from the small intestine of man, independent of its source, type and

Chemical and heat burn, Chemical and Heat Burn Chemical born and Heat ...

Chemical and Heat Burn Chemical born and Heat burn injuries have currently started receiving greater attention. The reason for this is perhaps the degree of discomfort and per

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