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.
State the Lantern Test The patient names colours displayed in the lantern and the mistakes are analyzed. This is not the best method of testing because it depends on the natu
Polynephritis in cattle Contagious bovine polynephritis is a specific infection of urinary tract of cattle. The causative agent is Corynebacterium renale, a rod shaped gram-po
P A TTERNS OF CLEAVAGE - Patterns of cleavage depends upon amount of yolk & distribution of yolk. These are following types - 1 . RADIAL CLEAVAGE PATTERN -
Mating and Fertilisation In all animals sperms are motile and have to move and seek the eggs to fertilise them. For this an aqueous environment is necessary. This need of a li
Calcium antagonists are not recommended for the treatment of CHF because of their negative inotropic effects. However, second-generation dihydropyridine-type calcium antagonists su
Indifferences in ionic composition Answer A. across membranes can be created through the action of ATP driven pumps as long as number of negative and positive ions on remain equal
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
What is meant by encystment
Define Efficiency - terminologies used in chromatography? Efficiency in chromatography is expressed as number of theoretical plates. H = L/N Where, H is heigh
Q How different are extracellular and intracellular digestion? What is the evolutionary advantage of extracellular digestion? Intracellular digestion is that in which the break
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