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.
Body Musculature - Locomotion The layout of the muscle layers surrounding the coelom is necessarily the same in all the major classes of Annelida. The body wall has a layer of
Proteins of Animal Origin - Milk: Milk: A value of 3.5% protein is often considered as an average for milk. Milk protein has traditionally been divided into 2 classes - casei
How the Rhizopus reproduce? Rhizopus usually reproduce asexually, but under unfavourable conditions, sexual reproduction (isogamous) occur resulting in formation of zygospores
What are the benefits of Soil testing Soil testing is done to assess the nutrient supplying capacity of the soil. The data obtained as a result of testing is useful for recom
Strawberries are quick frozen at a rate of 6500 kg/h. The fruit enters the freezer at a temperature of 15°C and is frozen to a final temperature of -20°C. Calculate the rate of hea
Chemical Stress - Mineral composition The living systems make use of several mineral ions that they might have encountered at the very origin or during evolution, particularly
Permanent Partial Disability - Injury from an Accident Permanent partial disability restrains the worker by doing the job he has been doing. He recovers from the injury in th
is a cyclone density dependent or independent
Q. Why is maternal milk important for the immune protection of the baby? Besides being nutritionally important like maternal milk participates in the defense of the baby agains
In 1954, Public Health Service organized an experiment in that nearly 2 million children in grades 1, 2 and 3 participated. Experiment was to test a vaccine. Name the disease c
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