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.
What is the Emperical evaluation Emperical evaluation based on: i) Time elapsed since stage one surgery - Considering the sigma cycle of bone formation in humans, a time pe
What is the primary structure of a protein? What is the importance of the primary structure? Ans) The primary protein structure is the linear sequence of amino acids that produc
Q. Describe the phylogenetic system of classification? 1) Hutchinson believed in Monophyletic origin of Angiosperms from a hypothetical group, which he' named, as Proangiosperm
What are the functional divisions of the nervous system? Functionally the nervous system can be separated into the somatic nervous system and visceral nervous system. The so
Define the Nutritional Assessment Tools? Malnutrition/protein energy malnutrition amongst elderly persons has been observed in various studies -be it hospitalized patients, nur
Indications for Surgery : Echocardiography or right heart catheterization can quantify tricuspid stenosis. It is categorized as Tricuspid valve repair is advised when ther
The major hazards encountered in the biological lab work are diseases like infections and allergies which are caused by handling live animals. dissections, plant and animal tissues
Cardiac Output - Circulation The cardiac output can be determined in a number of ways. The most common method is the Fick's principle. A. Fick a German physiologist in 1870 de
excretory organ of lizard
In lab rats, hair color and texture are controlled by two genes, the A gene for color and the B gene for texture. in both of these genes, the alleles show no dominance to each othe
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