Biology, asked by arnomls5246, 9 months ago

What is mean by chromosome what it's types how they belong to???

Answers

Answered by nallavariradhika
0

Explanation:

chromosome:

A chromosome is a DNA (deoxyribonucleic acid) molecule with part or all of the genetic material (genome) of an organism. Most eukaryotic chromosomes include packaging proteins which, aided by chaperone proteins, bind to and condense the DNA molecule to prevent it from becoming an unmanageable tangle.[1][2] This three-dimensional genome structure plays a significant role in transcriptional regulation.[3]

A chromosome is a DNA (deoxyribonucleic acid) molecule with part or all of the genetic material (genome) of an organism. Most eukaryotic chromosomes include packaging proteins which, aided by chaperone proteins, bind to and condense the DNA molecule to prevent it from becoming an unmanageable tangle.[1][2] This three-dimensional genome structure plays a significant role in transcriptional regulation.[3]Chromosomes are normally visible under a light microscope only when the cell is undergoing the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form).[4] Before this happens, every chromosome is copied once (S phase), and the copy is joined to the original by a centromere, resulting either in an X-shaped structure (pictured here) if the centromere is located in the middle of the chromosome or a two-arm structure if the centromere is located near one of the ends. The original chromosome and the copy are now called sister chromatids. During metaphase the X-shape structure is called a metaphase chromosome. In this highly condensed form chromosomes are easiest to distinguish and study.[5] In animal cells, chromosomes reach their highest compaction level in anaphase during chromosome segregation.[6]

Types of chromosome:

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. Additional protein structures called histones support the DNA molecule within the chromosome.

Metacentric Chromosomes:

Metacentric chromosomes have the centromere in the center, such that both sections are of equal length. Human chromosome 1 and 3 are metacentric.

Submetacentric Chromosomes:

Submetacentric chromosomes have the centromere slightly offset from the center leading to a slight asymmetry in the length of the two sections. Human chromosomes 4 through 12 are submetacentric.

Acrocentric Chromosomes:

Acrocentric chromosomes have a centromere which is severely offset from the center leading to one very long and one very short section. Human chromosomes 13,15, 21, and 22 are acrocentric.

Telocentric chromosomes:

Telocentric chromosomes have the centromere at the very end of the chromosome. Humans do not possess telocentric chromosomes but they are found in other species such as mice.

Similar questions