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!
Problem of Polarity
The control of polarity in regenerating coelentrates like hydra has received much attention for many years. You are already aware that while a hydra is cut in half, the half with the basal disc will form a hew hypostome and the half consisting of the hypostome will generate a new basal disc. Furthermore, if a hydra is cut into various segments perpendicular to the body axis, then each middle segment will regenerate both of the a basal disc and a hypostome. So every region of the hydra can give rise to a new organism.
Yet hypostomes, as well foot does not make anywhere or at all levels along the longitudinal axis of the animal; they form just only at the distal end. This indicates that a series of gradients arise from the two poles in Hydra that is rigidly polarized along the distal proximal axis. Grafting experiments have given further evidence for the existence of gradients in the hydra. When the hypostome tissue was added to the middle region of other hydra it formed a new bud with hypostome extending outward. When the basal disc cells were likewise grafted the new bud extended to form a new pedal disc and foot. In addition if grafts of both basal disc and hypostome cells were grafted together to the gastric region no supernumerary parts made. This observation suggests which signals from opposite ends of the hydra tend to counteract each other, causing the hydra to lose its polarity. Other experiments have as well shown which normal regeneration of the hypostome can be inhibited when an intact hypostome is grafted into the body of the hydra.
Lengthening of long bones in humans takes place in a specific area of the bone. This area is known as the: a) Cancellous bone b) Medullary canal c) Periosteum (pron: per-
a) Explain what is meant by ovulation. b) How often does it happen in humans? (a) Ovulation is the release of an ovum from a mature follicle in the ovary.
Minerals :- Iodine Food Source Iodised salt, sea food, plants and animals grown in areas where soil iodine is not depleted. Nutritional Functional role Esse
What is mechanical digestion? In molluscs, arthropods, earthworms, birds and vertebrates, in general, which organs respectively participate in this type of digestion? Mechanica
mitotic division
Explain the Psychological Management of eating disorders? All anorexia nervosa or bulimia nervosa patients are resistant to any kind of therapy and hospitalization may be a lif
Define Malnutrition - Effects on Milk and Effects on Mothers? Milk is the sole source of nourishment for many infants for upto 6 months or a year or even more. Therefore, the r
What action is EPA taking on plant-incorporated protectants? EPA has issued three final rules clarifying and formalizing EPA's framework for federal oversight of plant-incorpor
Functional Problems of implant failures The masticatory efficiency of the implant supported prosthesis depends on the anchorage related factors and the prosthesis related fact
DNA fingerprinting produces a unique banding pattern of DNA fragments for comparison with other DNA samples.
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