The following points highlight the six main parts of a chromosome. The parts are: 1. Pellicle and Matrix 2. Chromatids, Chromonema and Chromomeres 3. Centromeres 4. Secondary Constriction 5. Satellite 6. Telomere. Part # 1. Pellicle and Matrix: A membrane which surrounds each chromosome is said as pellicle. A jelly substance present inside the membrane is called as matrix. Presumably [...]
In this article we will discuss about:- 1. Meaning of Chromosomes 2. Number of Chromosomes 3. Size 4. Chemical Composition 5. Functions 6. Special Types. Meaning of Chromosomes: Chromosomes are the most important constituents of the nucleus and were first observed by Holfmeister (1848) in pollen mother cell of Tradescantia and called it nuclear filaments. Chromosomes are filamentous bodies which [...]
The following points highlight the four main types of structural changes in chromosomes. The types are: 1. Deletion 2. Duplication 3. Translocations 4. Inversions. Structural Change: Type # 1. Deletion: Deletion refers to loss of a portion of segment from a chromosome. It is also known as deficiency. Deletions have been observed in Drosophila, maize, tomato, wheat and several other [...]