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.
The luria-nebraska neuropsychological battery This procedure was first reported in 1978 in the form of two initial validity studies. Historically, Chirstensen, a student of the
What are the cells that produce the myelin sheath? Of which substance is the myelin sheath formed? In the central nervous system (CNS) the myelin sheath is made by apposition o
Scrapie This is a chronic fatal disease of sheep and occasionally of goats caused by a Prion agent similar to BSE. The disease is reported from Europe, North America and in a f
Can you use a regular syringe instead of a gas syringe in a lab
Define Types of Root Canal Perforations According to size According to size: Small perforation: ( smaller than #20 endodontic instrument ) mechanical damage to tissue is
Q. What do you mean by ST-Segment in Exercise Induced PVC? Ans. Over the years it has been believed that repolarization in ventricular ectopic beats had no diagnostic si
WHAT ARE STAKEHOLDERS?
It is elimination of an antigen or antibody from a sample by the process of adsorption, to which the complimentary antigen or antibody is bound.
What are main limitations on size that can be synthesized and how will that be change over next few years? A: Today, a 10kb gene or longer is built as part of the regular produ
Explain the Characteristics of Cancer? The important characteristics of cancer are excessive cellular multiplication, invasiveness and autonomy. The active process of invasion
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