Polytene chromosomes, Biology

Assignment Help:

POLYTENE CHROMOSOMES

  1. First seen by Balbiani in salivary glands of larva of Chironomus insect (belongs to order Diptera). Later on such chromosomes observed in several other insects (Drosophila).
  2. Polytene name proposed by Koller.
  3. Polytene Chromosomes composed of many Chromonema (512 to several thousands).
  4. In stained preparation, polytene Chromosomes appear striped with alternate dark and light bands. Dark band have high amount of histone.
  5. Several puffy and swollen areas are seen on polytene Chromosomes. These called Balbiani rings or puffs.
  6. Balbiani rings are site of rapid. m-RNA synthesis.
  7. Ecdyson hormone (moulting hormone) of insects stimulates formation of balbiani rings.
  8. Polytene chromosomes concerned with metamorphosis in insects.

2054_polytene chromosomes.png


Related Discussions:- Polytene chromosomes

Effect on knee extensor muscle during the step cycle, Healthy Person X is w...

Healthy Person X is walking on level ground.  Which of the following is true for the knee extensor muscle of X's right leg during the step cycle? A. The right knee extensor mus

What is conventional breeding, What is Conventional breeding Conventio...

What is Conventional breeding Conventional breeding is a process in which genes for pesticidal traits are introduced into a plant by natural methods, such as cross-pollination

Define hypoglycaemia, Let us now understand the definition, causes, signs a...

Let us now understand the definition, causes, signs and symptoms, diagnosis and treatment of hypoglycaemia. It is very important for you to learn about it because patient will be h

Spoilage of poultry and poultry products, Q. Explain Spoilage of Poultry an...

Q. Explain Spoilage of Poultry and Poultry Products? Poultry meat is the muscle tissue of chicken, ducks, turkey etc. The reference to poultry meat generally is the 'dressed ch

Radial artery-long term patency, Radial Artery (RA) :  Patency of...

Radial Artery (RA) :  Patency of RA is less than that of Ih4.A but much superior to a venous graft. One of the studies showed 90 per cent patency at 13 months and 83

Australopithecines, The first ever australopithecine fossil was found in 19...

The first ever australopithecine fossil was found in 1924 at Taung, South Africa. It was the skull of a 6 year old child showing a mixture of human and ape like features. This a

Swine influenza, Swine influenza Swine influenza, a highly contagious ...

Swine influenza Swine influenza, a highly contagious disease affecting the respiratory tract of pigs, is c a use d  b y a  vir us b e lo nging t o the ge nus I nflu e nz a vir

Main phases and clinical manifestations of schistosomiasis, Q. What are the...

Q. What are the main phases and clinical manifestations of schistosomiasis? The Schistosomiasis has acute and chronic phases and Days after the infection the cercarial dermatit

What is the clitellum of earthtworms, Q. What is the clitellum of earthtwor...

Q. What is the clitellum of earthtworms and where it is located? The clitellum is a special region of the annelid constituted by rings (metameres) with reproductive function. I

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