Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
Mixed Mitral Stenosis and Regurgitation The most common cause for a combined lesion is rheumatic, Very rarely; it could be of congenital origin. Regurgitation in a stenotic val
Fibro-osseous Retention V/S Osseointegration Fibro-osseous retention is the tissue to implant contact interposition of the healthy, dense collagenous tissue between the implant
a) What is meant by 'vaso-dilation'? b) What are the effects of vaso-dilation in the skin? (a) Vaso-dilation is an enhance in diameter of small arterioles and
Blunt or Non-penetrating Injury When body is struck by a blunt object such as steering wheel or blows to chest with blunt object. External injury may appear minor but the
What is the difference between the concepts of food chain and food web? The chain theory is a theoretical model to study the energy flux in ecosystems. In fact, in an ecosystem
Q. What do you know Zoological Parks? Zoological park has two faced aspects, the relationship between man and beast. There is awe and there is slaughter. There is worship and t
What compound composes most of the cell membrane? How is this compound suited to the function of the membrane? Phospholipid composes most of the cell membrane. The hydrophob
How to Calculate the Requirements for the Calcium in Body? Requirements for calcium depend upon the rate at which calcium is incorporated into bone; they are therefore highest
Define Dietary Management of Sepsis with or without MODS? Before we begin with the dietary management of patients suffering from sepsis with or without MODS let us read a case
Pre-surgical Prosthodontics Radiographic investigation: The radiologic investigations are critical to evaluate the bone quality and bone quantity. 1. Panoramic Radiograph
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd