Where is the polytene chromosome located? Polyploid chromosomes are usually found in the interphase nuclei of some tissues of fly larvae. Polychromosomes are very useful for analyzing many aspects of the organization of the eukaryotic interphase chromosome and the genome as a whole.
What organ is generally used to find the multilinear chromosome in Drosophila? Polyploid chromosomes are formed in the giant salivary gland of Drosophila during development by multiple rounds of genome replication without cell division to generate multilinear chromosomes containing up to 1,000 copies of DNA per chromosome.
What are polygenic chromosomes and how are they formed? Polyploid chromosomes develop from the chromosomes of the diploid nuclei by successive duplication of each chromosomal element (chromatid) without separating them. The newly formed chromatids remain longitudinally attached and together form a cable-like structure, referred to as multilinear chromosomes.
Is there a polychromosome fig in humans? While polygenic chromosomes are frequently found in insects, they are essential in diverse organisms from giants to plants to humans, and play important roles in disease development.
Where is the polytene chromosome located? Related Questions
What is the explanation of the polytene chromosome in detail?
Polychromosome. (science: cell biology) Giant chromosomes resulting from the successive reproduction of homologous pairs of chromosomes, linked together (intertwined) without chromosome segregation or nuclear division.
How do you know if a chromosome is polyploid?
Polyploid chromosomes, in interphase, are seen to have distinct thick and thin band patterns. These patterns were originally used to help map chromosomes, identify small chromosomal mutations, and determine taxonomy. They are now used to study the function of genes in transcription.
What are Balbiani rings?
Balbiani rings are exceptionally large puffs on polyploid chromosomes in dipteran Chironomus tentans. Such jetting is particularly suitable for studies of active gene structure and the synthesis and transport of specific RNA protein (RNP) molecules.
Where is the bulb chromosome located?
Lamp chromosomes (LBCs) are relatively active chromosomes found in the germinal vesicle (GV) of the large oocytes of many vertebrate and invertebrate animals and also in the unicellular giant alga Acetabularia. These cells are all in the prophase of the first meiotic division.
What is the difference between bulb chromosome and polygonal chromosome?
The main difference between bulb chromosome and chromosome is that polyploid chromosomes are found in salivary glands and other tissues of insects while bulb chromosomes occur in the eggs of vertebrates except for mammals and some invertebrates.
Who discovered the lamp chromosome?
Brush chromosomes in shark egg cells (Ambystoma mexicanum) were discovered 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 “bulb chromosome” into the nomenclature. biological.
What genetic process occurs in a puff of a polygonal chromosome?
These jets and Balbiani loops are sites of active RNA synthesis. Therefore, multiple chromosomes, more specifically the phimosis and Balbiani loops are excellent tools for studying induction and the process of transcription.
How are brush chromosomes formed?
Chromosomes transform into a bulb brush shape during diplotene phase of meiotic prophase I due to active transcription of many genes. Each side loop contains one or several transcription units with a DNA axis polarized RNP matrix coating of the loop.
Who proposed the chromosomal theory of heredity?
(a) Walter Sutton and (b) Theodore Boveri are credited with developing the chromosomal theory of heredity, which states that chromosomes carry the unit of heredity (genes).
What is a chromosome drawing?
Noun. Graphical representation of the locations of genes on chromosomes, obtained by observing chromosome bands or by determining the degree of association between genes See also genetic map.
Why is acetic acid used in many fig chromosomes?
Acetic acid is another known non-coagulant stabilizing agent known for its swelling effect on tissues [15] that in the case of polylinear chromosome formations it helps to accommodate chromatin extension in interband regions [20].
Which part of the chromosome is referred to as the Balbiani loop?
Chromosome infusion. Electron micrographs of specific brush strokes, called Balbiani rings, of the multiple chironomus chromosomes of the salivary gland show the chromatin arranged in rings (Figs. 4-42 and 4-43), just like that observed in amphibian brush chromosomes discussed previously.
What are Balbiani rings and where can they be found?
Balbiani loops are sites of particularly active RNA synthesis on the polyploid chromosomes of Chironomids. Three such loci are located on the fourth chromosome in the salivary glands of Chironomus tentans.
Who discovered the b chromosome?
B chromosomes have been of interest since they were first discovered in the plant bug Metapodius, by Wilson in 1906, 1907 [214, 215].
What is the function of the Lampbrush chromosome?
Lamp chromosomes are also involved in the production of ‘disguised’ mRNAs for early development. Giant granular loops can either be the sites where such mRNA is packaged or they can be sites where specific changes occur in the deoxyribonucleoprotein fibrils.
Can a woman have a Y chromosome?
Each person usually has one pair of sex chromosomes in each cell. There is a Y chromosome in males, who have one X chromosome and one Y, while females have two X chromosomes.
What are the four types of chromosomes?
On the basis of the position of the centromere, chromosomes are classified into four types: metric, subcentric, acrocentric, and telocentric.
What 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. Identification of genes on each chromosome is an active area of genetic research.
What are the puffs in polychromosomes?
Bloating is the term that describes the structural changes in multilinear chromosomes. If one observes the polysynaptic chromosomes during the late prematurity stage, different bands will appear bulging. For 40 years, this has been understood as the result of gene activity.
Do humans have lamprey chromosomes?
Human chromosomes and the other chromosomes of mammals do not form identifiable chromosomes in eggs or in any somatic cells.
What is the function of chromosomes?
The most important function of chromosomes is to carry the basic genetic material – DNA. DNA provides genetic information for various cellular functions. These functions are essential for the growth, survival and reproduction of organisms. Histones and other proteins cover the chromosomes.
