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 common complications with spinal trauma patients, Define Common comp...

Define Common complications with spinal trauma patients? Common complications with spinal trauma patients include pressure sores or decubitus ulcers, hypercalciuria and renal s

Lethal gene, LETHAL GENE (2:1 Instead of 1 : 2 : 1 or 3 : 1) (i)       ...

LETHAL GENE (2:1 Instead of 1 : 2 : 1 or 3 : 1) (i)         All the genes present in an organism are not useful, but some of them show harmful effects and sometimes may cause d

Determine the reliability of the battery, Determine the reliability of the ...

Determine the reliability of the battery The issue of reliability of the battery has been addressed, with reasonably successful results. Clinical interpretation of the battery

Association of fibrinogen with cardiovascular risk factors, Q. Association ...

Q. Association of Fibrinogen With Cardiovascular Risk Factors? Ans. Fibrinogen, a large glycoprotein made mostly in the liver, is a clotting factor that activates thrombin

State the term - functional neuroanatomy, State the term - Functional neuro...

State the term - Functional neuroanatomy Functional neuroanatomy focuses on the study of anatomy using psychological measures. One application of this kind of research is to he

State the types of blood vessels, Blood Vessels There are three types o...

Blood Vessels There are three types of blood vessels. They are: 1) Arteries: Arteries carry blood from heart to different organs. They have thick wall. 2) Veins: Vein

World conservation strategy proposes various steps , WORL D CONSERVATION S...

WORL D CONSERVATION STRATEGY PROPOSES THE FOLLOWING STEPS - 1.       Preservation of critical habitats. 2.       Protection of wild life in situ (in natural habitats) as we

Draw decanol, Draw decanol, plamitic acid (C16:0 fatty acid) and the result...

Draw decanol, plamitic acid (C16:0 fatty acid) and the resulting wax ester generated by a dehydration reaction between both molecules.

Identical karyotypes and identical genomes, Q. Can two normal individuals o...

Q. Can two normal individuals of the same species with sexual reproduction have identical karyotypes and identical genomes? And how is the human karyotype usually represented?

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