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

Physical signs of aortic regurgitation, Q. Physical Signs of aortic regurgi...

Q. Physical Signs of aortic regurgitation? Chronic severe aortic regurgitation is characterized by wide pulse pressure and multiple peripheral signs it produces. Sharp rapid up

Soil – plant – animal relationship, Soil – plant – animal relationship ...

Soil – plant – animal relationship The plants derive the minerals from soil, and the animals from the plants / feed they consume and there is a dependent interrelationship bet

What is myocardial infarction, Q. What is myocardial infarction? The My...

Q. What is myocardial infarction? The Myocardial infarction is the condition in which an area of this tissue or the entire heart muscle dies by hypoxia due to lack of blood irr

What are the general symptoms of brain tumors, What are the general symptom...

What are the general symptoms of brain tumors The general symptoms of brain tumors, which result from increased intracranial pressure, include headache, vomiting, swelling of t

What are the pancreas, Pancreas Insulin (β cells) Promotes glucose en...

Pancreas Insulin (β cells) Promotes glucose entry in many cells, and in this way controls carbohydrate metabolism. Glucagon (α cells) Increases synthesis and release of

What effects on the inheritance of alleles, Independent assortment has whic...

Independent assortment has which of the following effects on the inheritance of alleles? a.Alleles on the same chromosome are not always inherited together. b.Alleles on diff

Post disease as a result -endodontists, If the condition or the post diseas...

If the condition or the post disease as a result of intraradicular infection----> treated conventionally via apex " non-surgical ", ---->Here we have 2 options either coronal

Explain short term complications, Q. Explain Short term complications? ...

Q. Explain Short term complications? Short term complications may arise due to GERD which may in turn increase the frequency or severity of this disease. One of the complicatio

Alcohol related emergencies, Alcohol Related Emergencies: Alcohol is o...

Alcohol Related Emergencies: Alcohol is one of  the most serious health problems. Alcoholism is defined as a primary or chronic disease with genetic, psychological and environ

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