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!
Female Gametophyte
The development of a female gametophyte is initiated with the enlargement of one of the megaspores (usually the one close to the chalaza in a linear tetrad) followed by three mitotic divisions. Thus, the female gametophyte, also called the embryo sac is almost always a 7-celled or 8-nucleate structure. The eight nuclei thus formed organize into the egg apparatus, central cell with two polar nuclei and three antipodal cells. This mode of embryo sac development occurs in the majority of flowering plants.
There are variations from this mode of female gametophyte development. In order to visualize these deviations let us recall the formation of megaspore tetrad. Out of the four megaspores, three degenerate and only one participates in the formation of embryo sac. This mode of development of female gametophyte is known as the monosporic type. In some plants, two megaspores out of four participate. For example, if after meiosis, the lower or the upper dyad produces the embryo sac and the other degenerates, the development is termed bisporic. Sometimes, cell plate formation does not occur after any of the meiotic divisions and all the four megaspore nuclei contribute to embryo sac formation. 'This is called tetrasporic type of development. Depending upon the orientation and subsequent behavior of the megaspore nuclei and their derivatives, the tetrasporic gametophyte may be of several types.
What are the Technique of Operation Cardiovascular Surgery? Technique of Operation Cardiovascular Surgery : The operation is done on cardiopulmonary bypass with profound h
Explain the Determination of Hydrolysis Hydrolysis of calcium pantothenate in acidic medium produces α,γ-dihydroxy-β,β-dimethylbutyrolactone, which reacts with hydroxylamine i
Categorisation of Neuropsychological Assessment One can divide neuropsychological assessment into two areas: i) Comprehensive and ii) Specialised assessment. Comprehen
Determine the working of Law of diminishing return According to the 'Law of diminishing return' the increase in the yield by a unit increase of the defi cient factor is proport
Which of the following is true in a skeletal muscle? A. Movement of the cross-bridge occurs only when the myosin head is detached from the actin molecule. B. The binding of
locomotary organ in mollusca
How many grams of sodium dodecyl sulfate (mw = 288.37) would you dissolve in 80mLs of water to make a 20% solution of SDS?
Taxonomic Hierarchy The sheer complexity of organisms seems so bewildering that some people believe, life to be unfathomable by the rational mind. Biologists constantly chip aw
what are the general characters of chordates? At least 10 characters.
Demonstrate the structure of mitochondria The structure of mitochondria has been examined in great detail with the aid of the electron microscope, and it is now possible to des
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