CHAPTER 10 Molecular Structure of Chromosomes and
Transposable Elements
10.1 Organization of Functional Sites Along Bacterial Chromosomes
10.2 Structure of Bacterial Chromosomes
10.3 Organization of Functional Sites Along Eukaryotic Genomes and Repetitive Sequences
10.4 Sizes of Eukaryotic Genomes and Repetitive Sequences
10.5 Transposition
10.6 Structure of Eukaryotic Chromosomes During Cell Division
Chromosomes: structures within living cells that contain genetic material.
Genome: the entire complement of genetic material in an organism/species.
Bacteria: single circular chromosome.
Eukaryotes: genome is found in different cellular compartments (nucleus,
mitochondria, chloroplast genome (only for plants).
Primary function of genetic material: to store the information needed to produce the
characteristics of an organism.
Chromosomal sequences facilitate four important processes:
1. The synthesis of RNA and cellular proteins;
2. The replication of chromosomes;
3. The proper segregation of chromosomes;
4. The compaction of chromosomes so that they fit within living cells.
, 10.1 Organization of Functional Sites Along Bacterial Chromosomes
The chromosomal DNA is a circular molecule, though some bacterial species have linear
chromosomes. More than one (1 – 4) copy of this single type of chromosome can be found
within one bacterial cell (depending on growth conditions and cell cycle phase). The
chromosome typically consists of a few million base pairs and a few thousand genes. Protein-
encoding genes (structural genes) account for the majority of the bacterial DNA.
Intergenic regions: non-transcribed regions of DNA located between adjacent genes.
Bacterial chromosomes have one origin of replication: a nucleotide sequence that functions as
an initiation site for the assembly of several proteins required for DNA replication. Repetitive
sequences (interspersed within the intergenic regions): these sequences may play a role in a
variety of genetic processes (DNA folding, DNA replication, gene regulation, genetic
recombination).
Transposable Elements
10.1 Organization of Functional Sites Along Bacterial Chromosomes
10.2 Structure of Bacterial Chromosomes
10.3 Organization of Functional Sites Along Eukaryotic Genomes and Repetitive Sequences
10.4 Sizes of Eukaryotic Genomes and Repetitive Sequences
10.5 Transposition
10.6 Structure of Eukaryotic Chromosomes During Cell Division
Chromosomes: structures within living cells that contain genetic material.
Genome: the entire complement of genetic material in an organism/species.
Bacteria: single circular chromosome.
Eukaryotes: genome is found in different cellular compartments (nucleus,
mitochondria, chloroplast genome (only for plants).
Primary function of genetic material: to store the information needed to produce the
characteristics of an organism.
Chromosomal sequences facilitate four important processes:
1. The synthesis of RNA and cellular proteins;
2. The replication of chromosomes;
3. The proper segregation of chromosomes;
4. The compaction of chromosomes so that they fit within living cells.
, 10.1 Organization of Functional Sites Along Bacterial Chromosomes
The chromosomal DNA is a circular molecule, though some bacterial species have linear
chromosomes. More than one (1 – 4) copy of this single type of chromosome can be found
within one bacterial cell (depending on growth conditions and cell cycle phase). The
chromosome typically consists of a few million base pairs and a few thousand genes. Protein-
encoding genes (structural genes) account for the majority of the bacterial DNA.
Intergenic regions: non-transcribed regions of DNA located between adjacent genes.
Bacterial chromosomes have one origin of replication: a nucleotide sequence that functions as
an initiation site for the assembly of several proteins required for DNA replication. Repetitive
sequences (interspersed within the intergenic regions): these sequences may play a role in a
variety of genetic processes (DNA folding, DNA replication, gene regulation, genetic
recombination).
