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

Asexual reproduction that occurs in hydras, Q. What is the kinds of asexual...

Q. What is the kinds of asexual reproduction that occurs in hydras? Hydras reproduce asexually by budding.

Acute versus chronic heart failure, When the syndrome sets in at a rapid ra...

When the syndrome sets in at a rapid rate before the compensatory mechanisms become operative, acute heart failure develops. The examples are acute heart failure due to acute myoca

Conduction of impulse, CONDUCTIO N OF IMPULSE - IN NON-MYELINATED AXO...

CONDUCTIO N OF IMPULSE - IN NON-MYELINATED AXONS - The impulse moves along the axon as local effect by altering the permeability of neighbouring Na +  channels and af

What is the importance of water for enzymatic activity, What is the importa...

What is the importance of water for enzymatic activity? Enzymes, biological catalysts, rely on water to reach their substrates and bind to them. There is no enzymatic activity

Explain about gelation, Gelation Agar gels can be formed in very dilute...

Gelation Agar gels can be formed in very dilute solutions containing a fraction of 1% agar. In fact gelation is perceptible at concentrations as low as 0.04%. These gels are ri

What is the ranges of tolerance and performance optima, What is the ranges ...

What is the ranges of tolerance and performance optima? Ranges of Tolerance and Performance Optima :   When it comes to physical factors or resources, most species are able to

Can you explain the anoxia, Q. What is the anoxia? Anoxia is a situatio...

Q. What is the anoxia? Anoxia is a situation in which there is no available oxygen in the cell without oxygen the respiratory chain stops there is no ATP production the cell do

Explain the mechanisms of endosseous integration, Mechanisms Of Endosseous ...

Mechanisms Of Endosseous Integration Three terms may be used to describe individual aspects of bone formation process that can occur around implants. They are Osteoconduction,

Explain the food applications of guar, Explain the Food Applications of gua...

Explain the Food Applications of guar Guar imparts smoothness to ice cream by promoting small ice crystals during the freezing process. Guar gum in the dressing of cot

Functions of kidney, FUNCTION S OF KIDNEY - 1.      Excretion of nitro...

FUNCTION S OF KIDNEY - 1.      Excretion of nitrogenous wastes. 2.      Maintenance of water balance or osmoregulation. 3.      Acid base balance or regulation of pH.

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