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!
Threshold Value of Different Larval Tissues
Threshold value of dissimilar larval tissues for the thyroid hormone concentration
One of the main problems of metamorphosis is the co-ordination of developmental events. The tail should not degenerate till some another means of locomotion, namely the limbs develop, and the gills should not regress till the animal can employ its newly developed lung muscles. Kollros (1961) illustrated the possibility of this coordination that displays that different larval tissues have diverse threshold value for thyroxine. In other words the different larval tissues are sensitive to dissimilar concentrations of thyroid hormone.
This model is termed as the threshold concept. It has been observed that structures in the tadpole that change early during metamorphosis are more sensitive to and have low threshold value to thyroxine, than those which go through transformation at a later stage. As metamorphosis commences the thyroid hormone level slowly builds up and different events occur at different concentrations of the hormone. Experimental studies have revealed that tadpole pans that have a low threshold respond earlier during metamorphoses than those parts comprising a high threshold response. In other words, the threshold value reflects the order where metamorphic changes occur in normal development. In urodeles the bulging of eyes reacts to the weakest dose of thyroid hormone (minimum threshold) and thus is the first event in metamorphosis. This is followed by reduction of fin fold and the shortening and disappearance of external gills. After which takes place the closure of gill clefts and transformation of skin.
Q. What are the few examples of the energetic function of organic molecules? Ans. Since they are complex molecules, organic molecules store large amount of energy, present
Raw Material for Industry - impacts on biodiversity The industry, producing goods and services, relies and impacts on biodiversity directly. Much of the raw material that goes
Explain the Types of surgery ? Primary repair of ventricular septal defect has to be done whenever possible. III complex malformations associated with large VSD, pulmonary arte
Is a viral infection treated with the same kind of drug that treats bacterial infections? Antibacterial drugs, potent against a great variety of bacteria, are not effective aga
Assume that you have a stock solution of epinephrine at a concentration of 1mg/ml. Further assume that there are 20 drops/ml. a. Calculate the number of drops of the stock solution
mode of digestion in coelenterata
How Ignorance and Poor Socioeconomic cause PEM? Status Improper childcare, either as a result of lack of knowledge or lack of time for mother, could also contribute to the onse
Blood transfusion The blood of Raja cannot be transfused to Rama because the blood group of Raja is ‘B' and blood group of Rama is ‘A'. If Raja's blood with group ‘B' is
formulation of RDA
The potassium-sparing agents spironolactone, triamterene, and amiloride are often useful in combination with the loop diuretics and thiazides. Triamterene and amiloride act on the
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