Morphogenesis and totipotency, Biology

Assignment Help:

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.


Related Discussions:- Morphogenesis and totipotency

Define the diseses shigellosis, Define the diseses Shigellosis Shigello...

Define the diseses Shigellosis Shigellosis or bacterial dysentery is caused by facultative anaerobic, gram-negative, non-spore forming, rod-shaped  Shigella in the family enter

How does the poison cyanide act upon the aerobic respiration, Q. How does t...

Q. How does the poison cyanide act upon the aerobic respiration? Cyanide is a poison that restrains the last cytochrome of the respiratory chain, interrupting the ATP formation

Explain the complexity level of the nervous system, Q Is the tubular-dorsal...

Q Is the tubular-dorsal nervous system of chordates associated to radial or lateral symmetry? How does that explain the complexity level of the nervous system reached by the verteb

Water to flow within the xylem from the roots to the leaves, What are the f...

What are the forces that facilitate to make water to flow within the xylem from the roots to the leaves? Water enters the roots because of the root pressure and a water column

Difference between type ii and type i diabetes mellitus, Q. What is the dif...

Q. What is the difference between type II diabetes mellitus and type I diabetes mellitus? Type I diabetes also known as insulin-dependent diabetes (as this name is not adequate

Clinical features - infective endocarditis, The clinical  manifestations of...

The clinical  manifestations of IE result from the local destructive effects of intracardiac infection; the embolization of bland or septic fragments of vegetations to

Explain left ventricle enlargement, Q. Explain Left Ventricle Enlargement? ...

Q. Explain Left Ventricle Enlargement? The left ventricle (LV) is ellipsoid in shape. It lies behind, and to the left of the right ventricle. Its long axis lies at about 45 deg

A field trip to observe flowers, A field trip to observe flowers:- Plan...

A field trip to observe flowers:- Plan a field trip to view flowers in bloom. If no interesting wildflowers can be found growing near the school, the trip can be planned to a p

Define caution for the use of pipettes - food microbiology, Caution for the...

Caution for the use of Pipettes - Food Microbiology? (1) Never do pipetting with mouth. (2) For culturing, sterilized pipettes should be used. (3) Never keep pipettes on

Regents for estimation of reducing sugar by fehling soxhlet, Define Regents...

Define Regents for Estimation of Reducing Sugar by Fehling Soxhlet Method? Fehling A solution - copper sulphate solution Fehling B solution - alkaline tartarate so

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd