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.
Q. Mistakes may happen during each copying process. The same is true for the DNA replication. Are there correction systems in cells that try to mend those mistakes? Under which sit
Q. What is Ocean shorelines? Ocean shorelines include rocky coasts and sandy beaches that are particularly rich in diverse life forms. Rocky shorelines support a diversity of o
Define drawbacks for underwater weighing method? Since the major drawbacks with UWW method are that the subject needs to be totally submerged underwater and exhale all of the a
α - amylase activity by GA 3 - Dormancy Of the enzymes required for the digestion of starch α-amylase appears immediately after the start of germination. It was found that
Illustrate the types of Bone Remodeling Bone remodeling occurs on existing bone surfaces. However, unlike modeling, remodeling cannot cause large changes in bone structure at a
Run off Some of the rainfall is soaked into the soil and excess water flows over the land surface along the natural slope of the area. Run off is the main source of water for l
What is Implant therapy Successful implant therapy requires systematic thorough and meticulous planning to determine the ultimate prognosis and end result that will satisfy th
a) Mention the scientific term used for modified form of reproduction in which seeds are produced without fusion of gametes. b) What does ecological niche of an organism represe
How are grasslands classified? Grasslands might be classified into steppes and savannahs. In the steppes the prevailing vegetation is grass, as in the pampas of South America
Information Processing in Sensory Neuron You have previously seen that the sensory neuron transmits the information it receives, as an action potential along its axon. We desc
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