Chromosomes

Difference Between Polytene and Lampbrush Chromosome

Difference Between Polytene and Lampbrush Chromosome

The main difference between polytene and lampbrush chromosome is that polytene chromosomes occur in the salivary glands and other tissues of insects whereas lampbrush chromosomes occur in the oocytes of vertebrates except for mammals and some invertebrates.

  1. What are Polytene and Lampbrush chromosomes?
  2. What is meant by Lampbrush chromosome?
  3. What is the function of Lampbrush chromosome?
  4. Where is Lampbrush chromosome found?
  5. What are Balbiani rings?
  6. What are the 4 types of chromosomes?
  7. Do humans have polytene chromosomes?
  8. Who discovered Lampbrush chromosome?
  9. What do you mean by giant chromosome?
  10. Can a woman have Y chromosome?
  11. Which is the largest chromosome?
  12. What are Chromonemata?

What are Polytene and Lampbrush chromosomes?

[II] Polytene chromosomes:

These are also giant chromosomes but relatively smaller than lampbrush chromosomes, found in the larvae of certain dipterans. ... Because of their large size showing numerous strands these are named as polytene chromosomes (name suggested by Kollar) or commonly salivary gland chromosomes.

What is meant by Lampbrush chromosome?

Lampbrush chromosome (immature eggs) of most animals, except mammals. ... Chromosomes transform into the lampbrush form during the diplotene stage of meiotic prophase I due to an active transcription of many genes. They are highly extended meiotic half-bivalents, each consisting of 2 sister chromatids.

What is the function of Lampbrush chromosome?

Lampbrush chromosomes are also involved in the production of “masked” mRNAs for early development. The giant granular loops could either be the sites where such mRNAs are packaged or they could be sites where specific alterations of the deoxyribonucleoprotein fiber take place.

Where is Lampbrush chromosome found?

Lampbrush chromosomes (LBCs) are transcriptionally active chromosomes found in the germinal vesicle (GV) of large oocytes of many vertebrate and invertebrate animals and also in the giant single-celled alga Acetabularia. These cells are all in prophase of the first meiotic division.

What are Balbiani rings?

Balbiani rings are exceptionally large puffs on the polytene chromosomes in the dipteran Chironomus tentans. These puffs are particularly well suited for studies of the structure of active genes and the synthesis and transport of specific RNA-protein (RNP) particles.

What are the 4 types of chromosomes?

There are four main types of chromosomes: metacentric, submetacentric, acrocentric, and telocentric. Chromosomes are found within the nucleus of most living cells and consist of DNA that is tightly wound into thread-like structures.

Do humans have polytene chromosomes?

In particular polytene chromosomes are found in a specific subset of endopolyploid cells, which have undergone a variant cell cycle known as the endocycle.
...
Table 1.

TypeAnimals
SubtypeMammals
SpeciesHuman
Cell typeTrophoblast giant cell
•4 серп. 2017 р.

Who discovered Lampbrush chromosome?

Lampbrush chromosomes were discovered in sala- mander egg cells (Ambystoma mexicanum) by Flemming in 1882. Ten years later, LBCs were identified in shark egg cells and described by Rückert in 1982. It was Rück- ert who introduced the term “lampbrush chromosome” into biological nomenclature.

What do you mean by giant chromosome?

Polytene chromosomes were first reported by E.G.Balbiani in 1881. ... They are produced when repeated rounds of DNA replication without cell division forms a giant chromosome. Thus polytene chromosomes form when multiple rounds of replication produce many sister chromatids which stay fused together.

Can a woman have Y chromosome?

Typically, biologically male individuals have one X and one Y chromosome (XY) while those who are biologically female have two X chromosomes. However, there are exceptions to this rule. The sex chromosomes determine the sex of offspring.

Which is the largest chromosome?

Chromosome 1 is the largest human chromosome, spanning about 249 million DNA building blocks (base pairs) and representing approximately 8 percent of the total DNA in cells. Identifying genes on each chromosome is an active area of genetic research.

What are Chromonemata?

Chromomeres contain genes and sometimes clusters of genes within their structure. Aggregates of chromomeres are known as chromonemata. Cohesive proteins SMC3 and hRAD21(plays a role in sister chromatid cohesion) are found within chromomeres at high concentrations, and maintain the proper structure of chromomeres.

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