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

The salt concentration is higher than that of acid, Which of the following ...

Which of the following statements about buffers is true? Select one: a. A buffer composed of a weak acid of pKa = 5 is stronger at pH 4 than at pH 6. b. At pH values lower

Nutritional demands of sports and dietary recommendations, Define Nutrition...

Define Nutritional Demands of Sports and Dietary Recommendations? There is a strong relationship between nutritional status and physical training. Whether it is to maintain hea

Define pacinian corpuscules, Q. Define Pacinian corpuscules? Pacinian ...

Q. Define Pacinian corpuscules? Pacinian corpuscules are an example of sensory receptors scattered deep in the subcutaneous tissue underlying skin or in viscera.  These mech

Explain protoderm in primary growth in shoot, Explain Protoderm in primary ...

Explain Protoderm in primary growth in shoot? The protoderm is one of the so-called "primary tissues" because it is formed first during germination and subsequent bud growth an

What type of athlete, What type of athlete would have a above average react...

What type of athlete would have a above average reaction time please explain.

Pathophysiology of tricuspid regurgitation, Q. Pathophysiology of Tricuspid...

Q. Pathophysiology of Tricuspid regurgitation? Tricuspid regurgitation is associated with prominent venous filling waves and elevated right atrial venous pressures. Hepatic and

Muscles, what process provides the energy for muscle contraction?

what process provides the energy for muscle contraction?

Ice age, Ice age is an interval of geologic time between 2 million and 10,...

Ice age is an interval of geologic time between 2 million and 10,000 years ago during that period the northern hemisphere experienced several episodes of continental glacial advan

Noise pollution, Sound is a main mean of communication and entertainment an...

Sound is a main mean of communication and entertainment and is also very effective alarm system for some animal. A loud and unwanted or unpleasant sound causes discomfort and is ca

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