Polytene chromosomes, Biology

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

Posted Date: 10/8/2012 3:12:54 AM | Location : United States







Related Discussions:- Polytene chromosomes, Assignment Help, Ask Question on Polytene chromosomes, Get Answer, Expert's Help, Polytene chromosomes Discussions

Write discussion on Polytene chromosomes
Your posts are moderated
Related Questions
Explain about the Microbiological Study of Water? Water is the basic need of life. River, streams and underground water is the prime source for water. However, disposal of indu

What raw materials require for the manufacture of margarine Soybean and peanut (or groundnut) oils are of great economic importance. Refined soybean oil contains branched fura

What do you determine by Atriopore? The external opening to atrium. In cephalochordates water passes across pharyngeal slits into atrium and from there leaves through atriopore

Define about the Ascorbic acid (vitamin C)? Ascorbic acid was discovered as the anti-scurvy vitamin. Vitamin C (chemical names ascorbic acid and ascorbate) is the six-carbon la

Q. DEFINITION OF DIABETES MELLITUS? The word "diabetes" is derived from the Greek word meaning "a siphon". The patients of diabetes had polyuria (passing excessive urine) and "

Microfilaments - Role of Cytoskeleton Structures Microfilaments are as well present in all animal cells. They are found singly throughout the cytoplasm organized like a meshwo

Cleavage and Gastrulation Eventually, one spermatozoon fuses with the ovum to r restore the diploid genomic condition and activates all the potentials in the fertilized egg ce

Flagellates - Parasitic Protozoan Several flagellate protozoa parasitise man and live in the blood stream or tissues of the reticulo-endothelial system. Most significant of th

I will send any further instructions to you. The ist part of the assessment (1-7) that evaluates the chart i have done but it needs to be looked at to see if content okay & gram

Full - thickness flap with a c-shaped excisional incision In case where there is adequate soft tissue, both in terms of papillary height and labial bulk, the excision of the ep