Difference Between Chromatin and Chromatid

Chromatin vs Chromatid
 

The most important structures in the cell during division are the chromosomes which contain DNA. This is because they are responsible for the transmission of the hereditary information from one generation to the next. There are two types of chromosomes. Those are autosomes and sex chromosomes. Sex chromosomes are important in sex determination.

Chromatid

In eukaryotes, DNA is found in chromosomes in the nucleus. Chromosomes are made of a single molecule of DNA and proteins. Chromosomes are linear, and DNA in them is double stranded. There are many chromosomes in a single nucleus. In prokaryotes, a single DNA molecule which is double stranded forms the chromosome. There are no proteins in the chromosome. In viruses, the genetic material is either DNA or RNA. They may be double stranded or single stranded. It may be circular or linear.

Each chromosome contains one long molecule of DNA and is made up of millions of nucleotides. A nucleotide differs from each other only in the sequence of nitrogenous base pairs. Nucleotides are arranged in different ways, to form polynucleotide chains. Therefore, the base sequence of these chains differ from one another and thereby sequence of base pair.

In the molecule of DNA, different parts act as different genes. A gene is a specialized genetic information determined by a particular sequence of base pair. DNA molecule is most appropriate to function as the genetic material of organisms due to the following reasons. It has a simple, universal and a stable structure. It can store information as sequences of nitrogenous base pairs. Its information can be changed slightly in rare occasions. DNA is able to self replicate in order to produce exact copies.

During prophase of nuclear division, each chromosome can be seen with 2 chromatids and these are held together by centromere. During metaphase, some microtubules get attached to the centromere. During anaphase, centromeres split and chromatids are separated. After separation, each chromatid can be called as a chromosome. Chromatids are then drawn to the opposite poles of the cell. During telophase chromatids reach the opposite poles of the cell.

Chromatin

During the interphase of the cell cycle, chromosomes are not visible because they appear as thin, long thread like structures called chromatin. 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.