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

Define historical example for dynamical network, Define Historical example ...

Define Historical example for Dynamical Network? John Tyson constructed a nonlinear differential equation model representing the majority of the network of biochemical pathways

Cnidarians: obelia, why is obelia considered to be of special interest in Z...

why is obelia considered to be of special interest in Zoology as an animal showing an intermediate grade of organisation

What is anatomic concavities, What is Anatomic concavities Anatomic co...

What is Anatomic concavities Anatomic concavities present in the lingual surface of the mandible, the sublingual fossa anteriorly and the submandibular fossa posteriorly. Norm

Secretion of parathormone and calcium blood level, Q. What is the relation ...

Q. What is the relation between secretion of parathormone and the calcium blood level? The parathormone increases the calcium blood level since it stimulates the resorption (re

Cells, Suppose you were planning to use liposomes in an attempt to deliver ...

Suppose you were planning to use liposomes in an attempt to deliver drugs to a particular type of cell in the body, for example, a fat or muscle cell. Is there any way you might be

Explain in brief about the ciliary muscle, Explain in brief about the cilia...

Explain in brief about the ciliary muscle During accommodation the ciliary muscle contracts and in turn the size of the ciliary ring is reduced. This results in the suspensory

Define briefly about the conjugated proteins, Define briefly about the Conj...

Define briefly about the Conjugated Proteins? Conjugated proteins are made up of simple proteins combined with a non- proteinous substance. The non-proteinous substance is know

Digestive system, steps of digestive system in amoeba,with a clear picture ...

steps of digestive system in amoeba,with a clear picture description

Respiration, difference between anaerobic respiration and fermentation

difference between anaerobic respiration and fermentation

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