CHROMATIN AND CHROMOSEMES Flashcards
Who gave the term chromatin and on what basis?
The term chromatin was given by Fleming on the basis of its ability to stained with the basic dye like Feulgen reagent , fuschin
What are chromatin and what are they made up of?
Chromatin are loosely packed and diffused.
they are made up of nucleoprotein i.e.. nucleic acid and histone proteins.
What are the types of chromatin ?
Heterochromatin
Euchromatin
LEARN THE DIFFERENCES BETWEEN THE CHROMATINS…
DONE :D
How are chromosomes formed?
During the prophase the chromatin network condenses forming the chromosomes.
Who gave the term chromosome?
WALDEYER
Who first saw the chromosome and where ?
It was first seen by HEFMEISCHEN in the pollen mother cell of tradescantia.
What is the size of the chromosome?
5 micrometer
what is the shape of the chromosome?
V , L , J and i
What is the chemical nature of the chromosome?
- DNA - 40% { it is acidic and -tively charged }
- RNA - 1-2%
- Histone proteins - 50% { it is basic and +tively charged}
- NHC (Non histone chromosomal proteins) - 8.5%
- these are proteins other than histones
- used for higher level of packaging
Why are the histone proteins basic in nature?
They are basic in the nature because
- made up of basic amino acids i.e.
* Arginine
* Lysine
Centromeres are also known as ?
Primary constrictions
What are sister and non-sister chromatin?
- Chromatin of same chromosome are sister chromatin
* Chromatin of different chromosomes are non sister chromatin.
What are the types of chromosomes on the basis of their position ?
There are five types of chromosomes on the basis of their position:-
- Metacentric \ isobranchial chromosomes
- Submetacentric \ heterobranchial chromosomes
- Acrocentric \ sub terminal chromosomes
- Telocentric \ terminal chromosomes
- Acentric chromosomes
What are the special types of chromosomes ?
Giant chromosome
- Lamp brush chromosomes
- Polytene chromosomes
