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

Atp, what is atp explain in detail?

what is atp explain in detail?

Explain the term tracheostomy, Explain the term Tracheostomy ? If the d...

Explain the term Tracheostomy ? If the duration of mechanical ventilation is likely to be prolonged, it is wise to do an early tracheostomy. Otherwise, a tracheostomy is usuall

Maintenance and regulation of peripheral circulation, Maintenance and Regul...

Maintenance and Regulation of Peripheral Circulation Pressure receptors (baroreceptors) located in the wall of the internal carotid arteries and in the arch of aorta, when

Bacterial diseases-actinobacillosis, Actinobacillosis Synonym   : Woo...

Actinobacillosis Synonym   : Wooden Tongue Causative organism                  : Actinobacillus lignieresii Species affected                   : Ruminants, cattle and s

Physiological adaptation of parasites for infectioness, physiological adapt...

physiological adaptation of parasites for infectiousness?

What is myoglobin, What is myoglobin? What is the function of this molecule...

What is myoglobin? What is the function of this molecule in the muscle tissue? Myoglobin is a pigment same to hemoglobin and present in muscle fibers. Myoglobin has a great af

How is a prototype drug different from other drugs, How is a prototype drug...

How is a prototype drug different from other drugs in the same class?

Explain arteries in comparison to veins, Which of the below statements does...

Which of the below statements does NOT apply to arteries when comparing them to veins: a) Have thick walls b) Carry blood away from heart c) Highly elastic walls d) Ha

What do we mean by culture media, What Do We Mean By Culture Media? Cul...

What Do We Mean By Culture Media? Culture media, you would realize, is a solid or liquid preparation containing all the nutrients required by microbes for growth. So then, what

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