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!
Egg - Synergids
The three cells of the egg apparatus are arranged in triangular fashion with the egg sharing a common wall with the two synergids and the central cell. In the egg the wall is thicker at the micropylar end and is absent at the chalazal end. At this end the lateral walls of the egg cell appear to join the central cell wall. The egg cell wall is traversed by plasmodesmata on the sides of the two synergids and the central cell but not at its outer face. The egg cell becomes highly polarized early in its development. Polarity is expressed by the aggregation of cytoplasmic elements at the chalazal end of the cell. The micropylar end of the cell is occupied by a large vacuole. Thus, the distribution of the vacuole and cytoplasm in the egg cell is just the opposite of that in the synergids.
The ultra structure of the egg cytoplasm indicates that it is inactive. The mitochondria show only a few cristae. But for Zea mays, dictyosomes are either absent (Epidendrum) or are only a few in numbers. Where present, the dictyosomes exhibit an inactive state. Plastids are present in the egg; they often contain a striking difference from the male gametes. The egg cytoplasm is rich in ribosomes. In Plumbago capensis where the embryo sac lacks synergids. However many finger- like wall projections arise at the micropylar end of the egg cell. They resemble the filiform apparatus of the synergids. In this plant the egg cell seems to have taken over the role of synergids in addition to its own gametic function.
Write down any other possible explanations you think of.could the cooler have had any effect? Could something in the water be reasonable? Could there be an object in the water that
Phosphorus Phosphorus has been known as “master mineral” because it is involved in most metabolic processes. Phosphorus, which is stored in bones and teeth, is often discussed
What are the intermediate and the definitive hosts of the plasmodium? In the life cycle of the plasmodium humans are the middle hosts (where asexual reproduction takes place) a
Define Function of thiamin as Regulator of enzyme activity? Thiamin regulates the enzymes involved in carbohydrate metabolism. These are: a) Pyruvate dehydrogenase, which pr
characteristics of protozoans
Nitrogen Fixation As we have said before, atmospheric nitrogen cannot be used by plants or animals. It has to be first fixed. The term nitrogen fixation refers to the oxidatio
Bovine viral diarrhoea Bovine viral diarrhoea (BVD) and mucosal disease (MD) are clinically dissimilar disease syndrome yet have a common viral etiology. The acute disease is
What is parasitism? Parasitism is the ecological interaction in which a being lives at the expense of another. The parasite often does not cause immediate death of the host sin
human digestive system
Define Advantage & disadvantage of using Algae as source of protein? Advantage Produces proteins which have almost all the Essential Amino acids. Rich in tyrosine
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