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

How are radioactive probes useful in dna fingerprinting, How are radioactiv...

How are radioactive probes useful in DNA fingerprinting? Radioactive probes bind to specific fragments in a DNA sample like a donor gene. A probe can identify which bacteria ha

Explain the sticky films - food microbiology, Explain the Sticky Films - Fo...

Explain the Sticky Films - Food Microbiology? Sticky films or tape are pressed against the surface to be assessed. Exposed film/tape is then pressed on the agar plate and analy

State the definition of bio-medical waste, State the definition of Bio-medi...

State the definition of Bio-medical waste 'Bio-medical waste' means any solid and/or liquid waste including its container and any intermediate product, which is generated durin

Promoters - transgenic animals, Promoters The promoter region contains ...

Promoters The promoter region contains the DNA sequences that allow the formation of the transcription initiation complex that give the specificity of expression. Promoters are

Give the biological effects of aflatoxin, Q. Give the biological effects of...

Q. Give the biological effects of aflatoxin and List the various natural toxins present in food? Biological effects of aflatoxin include hepatotoxicosis, carcinogenesis and liv

Name the foods to avoid in soft diet, Name the Foods to avoid  in soft die...

Name the Foods to avoid  in soft diet include: Fried foods and nuts, rich pastries and desserts, Raw  vegetables, Heavily spiced foods, Gas-forming vegetables, S

What are trophic levels, What are trophic levels? How many trophic levels c...

What are trophic levels? How many trophic levels can a food chain have? The Trophic levels correspond to positions on a food chain. thus producers always belong to the first tr

Explain tuberculosis, Tuberculosis Tuberculosis is a chronic infectious...

Tuberculosis Tuberculosis is a chronic infectious disease which is caused by a bacterium - Mycobacterium tuberculosis.  It affects the lungs most commonly but call gel localize

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