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

Cytology, who is the first person who saw the cell

who is the first person who saw the cell

Explain water as a lubricant, Explain Water as a lubricant? All fluids...

Explain Water as a lubricant? All fluids have lubricating as they can make it easier for the solid materials to slip over one another. Water-based fluids act as lubricants in

Surface run-off - causes of water pollution, Surface Run-off - Causes of Wa...

Surface Run-off - Causes of Water Pollution The surface run-off from cultivated lands where inorganic fertilisers, pesticides, insecticides and rich manure are applied and sol

Indications for emergency surgery in ar, Indications for Emergency Surgery ...

Indications for Emergency Surgery in AR 1) Post balloon valvotomy AR with haemodynamic compromise 2) Acute thrombosis of prosthetic valve, not responding to thrombolysis

State the effects of smoking for diabetics patient, State the Effects of al...

State the Effects of alcohol and smoking for diabetics patient A major concern with alcohol consumption is the potential danger of hypoglycaemia (low blood sugar), especially w

Types of transport process in sieve tubes, Types of Transport Process in Si...

Types of Transport Process in Sieve Tubes The metabolites of all the mesophyll cells around the sieve elements join in a common pool to load via the surrounding transfer cells

Digestion of fats, Digestion of fats   A.  Production of bile salts in ...

Digestion of fats   A.  Production of bile salts in the liver and the secretion of those bile salts into the small intestine.   B.  Production of lipase in the pancreas and

How does the synthetic theory of evolution explain this fact, In hospitals ...

In hospitals where many tuberculosis patients are treated the population of the tuberculosis mycobacteria may be constituted of multiresistant (to antibiotics) strains. How does th

#title., poor metabolism phenotype will have

poor metabolism phenotype will have

Experiment of stanley miller (1953) on the origin of life, What was the exp...

What was the experiment of Stanley Miller (1953) on the origin of life? In 1953 the Stanley Miller arranged an experimental apparatus that simulated the atmospheric conditions

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