What are polytene and Lampbrush chromosomes?
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.
Is chromatin uncoiled?
Explanation: Chromatin is unpaired, they are uncoiled, long and thin sturctures inside the nucleus, it can be found throughout the whole cell cycle. When it undergoes further condensation it forms the chromosome. Chromosomes are condensed Chromatin Fibers.
How many chromosomes are in a polytene chromosome?
Polytene homologues are held together by somatic pairing. The centromeres of all four chromosomes aggregate to form a chromocentre that is seen amorphous and consists largely of heterochromatin. It is the process of making multiple copies of chromosomes without the segregation and cell division.
What is the difference between heterochromatin and euchromatin which is transcribed?
Heterochromatin maintains the structural integrity of the genome and allows the regulation of gene expression. Euchromatin allows the genes to be transcribed and variation to occur within the genes.
What is the significance of lampbrush chromosome?
Giant chromosomes in the lampbrush form are useful model for studying chromosome organization, genome function and gene expression during meiotic prophase, since they allow the individual transcription units to be visualized.
What is the difference between chromatin and chromatid?
Chromatin is long, thread like structures. These are made up of DNA and histone proteins. During cell division, chromatin becomes shorter and thickened structures called chromosomes. What is the difference between Chromatin and Chromatid? • Chromatin is long-thread like structures. These are made up of DNA and histone proteins.
What is the difference between euchromatin and heterochromatin?
Heterochromatin is a tightly packed form of chromatin that can silence gene transcription whereas Euchromatin is less condensed and contains most actively transcribed genes. Chromatin is comprised of histones and DNA: 147 base pairs of DNA wraps around the 8 core histones to form the basic chromatin unit, the nucleosome.
What happens to chromatin during prophase of cell division?
During cell division, chromatin becomes shorter and thickened structures called chromosomes. • During prophase of nuclear division, each chromosome can be seen with 2 chromatids and these are held together by centromere.
What is a sister chromatid?
A sister chromatid is either one of the two chromatids of the same chromosome joined together by a common centromere. During cell division, they are separated from each other, and each daughter cell receives one copy of the chromosome. Chromatin is divided into heterochromatin (condensed) and euchromatin (extended) forms.