Genome organisation Flashcards
What is the genome?
All of the genetic material present in a cell or organism.
What are the two genomes eukaryotes have?
Nuclear genome
Mitochondrial genome
What does the nuclear genome consist of?
23 pairs of chromosomes
How many protein coding genes and RNA genes does the nuclear genome contain?
21000 protein coding
6000 RNA genes
How is the nuclear genome inherited?
Maternal and paternal
Fusion of haploid gametes
What does the mitochondrial genome consist of?
Circular chromosomes
How many genes are in the mitochondrial genome, what do they code for?
37
24 code for non-coding RNAs and only 13 code for polypeptides
How is the mitochondrial genome inherited?
Maternally
What % of the nuclear genome codes for proteins?
1-2%
What does the non-protein coding nuclear genome consist of?
Repeat sequences,
Heterochromatin
RNA genes/regulatory sequences.
What are transposons?
Moveable repeat DNA elements that can create or remove DNA mutations.
What are the two main types of transposons?
Retrotransposons
DNA transposons
What do transposable elements result in?
Duplicates
How do DNA transposons copy?
Does not involve an RNA intermediate
DNA is instead cut out and pasted elsewhere.
Transposase enzymes cuts out the DNA transposon and ligates it into the target site.
What is a tandem repeat?
Pattern of one or more nucleotides is repeated and the repetitions are directly adjacent to each other.
What is satellite DNA, how large?
Large repeats (170 nucleotides) of sequences adjacent to eachother.
Where is satellite DNA found?
Centromeres and heterochromatin
What are VNTRs?
Variable number tandem repeats. Short sequence is repeated.
What are VRTRs useful for and why?
Analysis is useful in genetics and biology research, forensics, and DNA fingerprinting.
Show variations in length (number of repeats) among individuals.
How large are mini-satellite repeats?
10-50 nucleotides
How large are microsatellite repeats?
1-4 nucleotides
What is a gene?
Defined as a determinant of a Mendelian character
Also as a functional unit of DNA.
What protein coding genes does mtDNA code for?
ATP synthase, Fo (complex V)
Cytochrome c oxidase, (complex IV)
NADH dehydrogenase, (complex I)
What 3 complexes of the ETC are coded for by mtDNA?
I, IV, V
Does mtDNA code for all the ETC complexes?
No
What RNA is coded for by mtDNA?
tRNA some rRNA
Mitochondrial DNA is found in …
Both sperm and egg
Mitochondrial genome is composed of …
a double-stranded circular DNA molecule
Inheritance of mutations in the mitochondrial genome is…
Often associated with neuromuscular disorders
