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.
What are cilia and flagella? Cilia and flagella are structures found in prokaryotes as well in eukaryotic cells. They play defense, nutrition and movement roles for the cell. I
Define Objective of national programmes targeting infants? These programmes have the objective of hinging down under-5 mortality. Under Integrated Child Development Services (I
Nutritional and functional role of minerals in foods Essential elements including the main elements and a number of trace elements fulfill various functions: as electrolytes, a
Self- vs. Cross-Pollination A major advantage of self-pollination is its certainty. Continued self-pollination over many generations, however, results in weaker progeny. This
Individual Psychotherapy: It is conducted on one to one basis. It is effective when a therapeutic rapport develops between patient and therapist. The common types of indiv
What are analogies for mitochondria? Well, as you know, the mitochondria are the producers of most of a cell's energy and the nucleolus makes ribosomes. The cell wall is only i
What are the major divisions and representing species of the gymnosperms? This group of plants can be separated into conifers (pine, sequoia, cypress), that have flowers called
Photoreceptors Photoreceptors are concerned in absorption of light by photosensitive pigments. The chemical change involved produces the impulse concerned in the nerve cells.
What is Osmosis ? Osmosis : Osmosis refers to the diffusion of water across a semi-permeable membrane from an area of higher concentration of water to an area of lower con
Can enhancers work in trans? That is, can an enhancer on one piece of DNA activate a promoter on another piece of DNA. Propose an experiment to test this. Be sure to discuss any ap
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