Chromosomes are the nuclear components that play a vital role in heredity, mutation, variation, and evolutionary development. They were first observed by Karl Nagli in plant cells and later work established their relation to cell division. The number and morphology of chromosomes varies between species. Most bacteria have a single circular chromosome that is around 2 million base pairs in size, though some bacteria have multiple or linear chromosomes. The material that makes up chromosomes is called chromatin, which exists in two forms - euchromatin and heterochromatin. Chromosomes can be isolated from cells for further study.

1. chromosomes
Siva Prakash . k
Mcs . microbiology
Anjac .

2. chromosomes
• Introduction
• Historical
• Chromosome number
• Morphology characters

3. INTRODUCTION
chromosomes are the nuclear components of special organisation,
individuality and function.they are capable of self-reproduction and
play a vital role in heredity, mutation,variation and evolutionary
development of the species.

4. HISTORICAL
• Karl nagli observed rod-like chromosome in the nuclei of plant cell.
• A.Schneider published a most significants paper dealing with the
relation between chromosomes and stages of cell division.
• Strasburger discovered thread-like structures which appeared during
cell division.
• Benden and Bovery reported that number of chromosomes.
• Chromosomes was coined by W.Waldeyer .
• Thomas morgan and Hermann muller working with Drosophila
chromosomes.

5. CHROMOSOMES NUMBER
• The set of chromosmes of the gametic cell such as sperm and ova is
known as the gametic ,reduced haploid sets of chromosomes.the
haploid set of the chromosomes is also known as the genome

6. MORPHOLOGICAL CHARACTERS
SIZE:
Free-living bacteria need genetic information to synthesize proteins for
executing vital functions. Most bacteria have a single chromosome with DNA that is
about 2Mbp (mega base pairs) long (1Mbp51 000 000 base pairs), but the DNA
content of different species varies from 0.58 to greater than 9Mbp ofDNA, and
some bacteria have multiple chromosomes.
SHAPE:
• On a macroscopic scale, bacterial chromosomes are either circular or linear.
Circular chromosomes are most common, at least among the best-studied
bacteria. However, the causative agent ofLyme disease, Borrelia burgdorphei, has
a 2-Mb linear chromosome plus 12 different linear plasmids. Eukaryotic
chromosomes are invariably linear, and they have two ends, each carrying a
special structure called a telomere, and a organized region called the centromere
which allows the chromosome to attach to cellular machinery that moves it to
the proper place during cell division.

8. The four morphological type of chromosomes

9. structure

10. MATERIAL OF THE CHROMOSOMES
CHROMATIN:
the material of the chromosomes is the chromatin,the
structure of which has already been described in depending on their
staining properties,the following two types of chromatin may be
distinguished in the interphase nucleus:
I. EUCHROMATIN.
II.HETEROCHROMATIN
1.constitutive
2.facultative

12. chromosomes isolation method

13. Chromosomes present in our body

15. Thank you