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

Monitoring for infections, Monitoring for infections Many infections ar...

Monitoring for infections Many infections are common in diabetic patient. Most prominent are urinary tract infections. Others are skin problems (carbuncles), ear problems (otit

State the term - psychophysiology, State the term - Psychophysiology Th...

State the term - Psychophysiology This refers to the study of psychological theories using physiological measures. In other words, psycho-physiologists normally try to understa

Define observation or inference for barfoed test, Define observation or inf...

Define observation or inference for barfoed test? 1. Reddish brown precipitate is seen on the sides and bottom of the tube. The precipitate of the sides and bottom indicates th

What is the importance of vitamin A, What is the importance of vitamin A ...

What is the importance of vitamin A The importance of vitamin A is undisputable. You may already be aware about the functions/role of vitamin A in our body.  Vitamin A is absol

Define most probable number (mpn) method, Define Most Probable Number (MPN)...

Define Most Probable Number (MPN) Method? The MPN method is like agar shake tube method where no agar is used. The dilutions of the microbial suspension are made in liquid medi

What are colonies and societies, Q. What are colonies and societies? Th...

Q. What are colonies and societies? The Colonies are functional integrated aggregates formed by individuals of the similar species. The Colonies are often confused with a singl

Explain zalcitabine and adverse effects, Explain Zalcitabine and adverse ef...

Explain Zalcitabine and adverse effects Zalcitabine - Zalcitabine appears to be less effective, less convenient and more toxic than the other NRTIs; it is used rarely. Ad

Dna vs protein, Describe the difference between dna and protein. (structura...

Describe the difference between dna and protein. (structural unit, linkage bond, primary and spatial structure)

How to lower the risk of drug-nutrient interactions, How to Lower the Risk ...

How to Lower the Risk of Drug-Nutrient Interactions? Eat a healthy diet using the food guide pyramid. Follow directions on how to take medication (prescription and ove

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