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!
Morphogenesis and Totipotency
A chlamydomonas mother cell gives rise to two daughter cells by a simple division. But a leaf cell cannot give rise to a new plant except in cases like Bryophyllum or Kalanchoe. What makes a daughter cell of a zygote to loose the 'potential' to develop into a whole plant? Or if all the daughter cells possess this potential- i.e. if they are totipotent-why it does not express? These questions troubled Haberlandt-hundred years ago. He postulated that any living plant cell should be able to grow into a full plant. He experimented with mesophyll cells at a time when tissue culture had not been unheard for. His experiments failed because we now know that isolated mesophyll cells are not really easy to grow to unleash their morphogenetic potential.
F.C. Steward-who took up this work sixty years later-successfully cultured whole carrot plants from carrot phloem parenchyma cell. He published the papers in the American Journal of Botany in the late 1950's. Steward and his coworkers took 2 mg. tissues of secondary phloem of carrot roots and grew them in special flasks with nipples or tubes called tumble tubes. The medium was whites' medium with coconut water. These tubes/flasks were mounted on a wheel that was rotated on a shaft at the rate of 1 r.p.m. So that the pieces were alternately aerated and bathed in the liquid medium. There was an enormous increase in size of the explants. A callus ensued. A few peripheral cells slaughtered off into the medium and started dividing and gave rise to clumps,-occasionally with roots these could be transferred to semi-solid medium in (still) tubes. Shoots arose opposite the roots to yield full plants. Subsequently other parts were also used to, demonstrate cellular totipotency.
Define Plasma or serum ascorbic acid levels? The serum or plasma ascorbic acid levels are used as an index of ascorbic acid nutrition of humans. The normal serum values vary ov
How different are pteridophytes from bryophytes regarding substance transport? Pteridophytes are tracheophyte (vascular) plants, i.e., they have tissues specialized in conduct
What are food hydrocolloids? Food hydrocolloids are hydrophilic polymers of vegetable, animal, microbial or synthetic origin that generally contain many hydroxyl groups and ma
Equine infectious anaemia Equine infectious anemia (EIA), an acute or chronic viral disease of the equines, shows intermittent fever, loss of weight, depression, progressive w
Echocardiography is a very important tool in diagnosis of cardiovascular diseases and is used virtually in all categories of cardiovascular diseases. There are certain areas where
Structure of the Conduction System of the Heart Sinoatrial (SA) Node is the pacemaker node located in the right atrium near the opening of superior venacava. It is called
Q. Spoilage of Fish and other Sea Foods Fish and other marine foods are second only to meat and poultry as a staple animal food around the world. India is one of the important f
Duck plague Duck plague, caused by a member of Herpesviridae, has world wide distribution and occurs among domestic and wild ducks, geese, swans and waterfowls. Epidemiolo
Zoochory - Dispersal of Seeds Some fruits are eaten by animals and the seeds are passed out with the excreta (endozoochory). Plums, Lantana, grapes, figs and guava are example
Radiolarians - Protozoan Radiolarians are entirely marine planktonic species with spherical bodies and radiating pseudopodia known as axopods. The spherical body is divided in
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