Lecture 1 Flashcards
What is heterochromatin?
Repetitive DNA that is tightly packaged and condensed, and that cellular proteins can’t reach.
It is inert
and often found at telomeres (and often at centromeres too).
Describe the genome of bacteria
Most bacteria have a single circular chromosome.
It is not as complex or carefully packaged - and is therefore more readily available.
Less coiled and packaged.
Typical bacterial genome is a few million base pairs long
Why do some organelles have their own DNA
Because they are evolutionary descendants of previous independent prokaryotic organisms that made home inside a eukaryote.
From where is mitochondria inherited from?
Mitochondria with DNA is inherited from the mother ( - the egg cell)
How many genes does an organelle have?
typically around 10-20 genes.
What is metagenomics?
Its a study of all the genes in an environment.
You purify DNA from an environmental sample
The sequence DNA may be from thousands of different species
Often done with ecologies or communities that are not well understood
the study of a collection of genetic material (genomes) from a mixed community of organisms
What is a genome?
The complete set of genetic information of an organism
What is the smallest genome?
Viroid genome of the cadang-cadang
An RNA genome of 246 base pairs
Describe eukaryotic genome
Nuclear genome is carried on chromosomes, it consists of many proteins where DNA is wound up, packaged and condensed
The centromere is seen as the ‘handle’
Telemores are specialised sequences at the ends of chromosomes, theyre repetitive.
