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

Ecology, does jellyfish depend on solarenergy

does jellyfish depend on solarenergy

Colour coding rules for biomedical waste management, Q. Discuss the colour ...

Q. Discuss the colour coding rules for biomedical waste management and handling? Colour coding biomedical waste( management and handling) rules, 1998

Determine the nutritious meals to the elderly, Determine the nutritious mea...

Determine the nutritious meals to the elderly? The various considerations to be kept in mind for providing nutritious meals to the  elderly are highlighted herewith. Due

How is the cerebrum anatomically divided, Q. How is the cerebrum anatomical...

Q. How is the cerebrum anatomically divided? The cerebrum is divided into two cerebral hemispheres, the left and the right. Each hemisphere is made of four cerebral lobes: pari

Explain major role in contributing towards motivation, Major role in contri...

Major role in contributing towards motivation. Psychological factors: Depression, anxiety or phobia induced by illness,  life- style changes or medication effects, may hinder

Hemiplegic migraine and ophthalmologic migraine, Hemiplegic migraine and op...

Hemiplegic migraine and ophthalmologic migraine These are relatively rare and include loss of movement of the limbs and eyes, respectively.

Explain the role of lipoprotein, Explain the Role of Lipoprotein ? As d...

Explain the Role of Lipoprotein ? As discussed in the previous section, serum concentrations of Lp(a) are elevated in South Asians irrespective of their migrant status. Several

How many sodium dodecyl sulfate dissolve in 80 mls, How many grams of sodiu...

How many grams of sodium dodecyl sulfate (mw = 288.37) would you dissolve in 80 mLs of water to make a 20% solution of SDS?

Explain precautions for estimation of reducing sugar, Explain Precautions f...

Explain Precautions for Estimation of Reducing Sugar by Fehling Soxhlet Method? 1. Clamp the burette so that the tip of the burette is exactly above the mouth of the conical fl

Importance of nutritional needs for management of emergency, Define Importa...

Define Importance of nutritional requirements for management of emergencies? Knowledge of nutritional requirements for management of emergencies is therefore, important due to

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