Chromosomes 2 Flashcards
Name 5 Cis-acting non coding and not transcribed parts of the chromome
Enhancers Silencers Telomeres Centromeres Insulators
Name the trans-acting, non coding, transcribed
RNA
tRNA
What is the main role?
What are the other roles?
Main role= protein translation
Other role= adaptive protein synthesis
regulatory networks
rRNA
What is its main role?
Used during ribosomes biogenesis and translation
Used as riboenzymes
How long are long non-coding RNA?
What do they mostly contain?
What is their suggested function?
longer than 200 nt
mostly contain poly-A tails
epigenetic gene regulation -lnc DNA
What is the suggested function of cRNA?
binds to chromatin to modulate expression
How small are small Non-coding RNAs?
What is its role?
Smaller than 200 nt
mostly contain poly A tials
mainly regulatory and binds to target mRNAs leading to degradation or translation inhibition
What common feature to Transospons, LINES and SINES hvae ?
Mutagenic and important for genome evolution
What is a mutation?
What 2 ways can they occur?
ANY change in DNA base sequences
They can be heritable - occurring in the germ-line cell
OR transient -occurring in the somatic cell
Name 3 examples of point mutations
Insertions
Deletions
Substitutions
Name 4 larger mutations
Insertions
Duplications
Translocations
Deletions
How does mutation happen in terms of the mechanism of point mutation?
Mutagen can cause DNA damage or DNA base sequence error which is multiplied by DNA replication. It can be fixed by DNA replication
How does insertions and deletions occur ?
Due to errors in replication
What errors can occur during the mechanism of Chromosomal rearrangements?
DNA breakage/Illegitimate crossing over
What are the 3 type of mutagens and what mutations can they create?
Physical- large double-stranded breaks
Chemical- smaller mutations
Biological- large mutations
Define Transposable elements
Mutagenetic engines.
Mobile DNA elements that move from one place to another in the genome.
What are the two classes of Transposable elements?
Class I- Retrotransposons
Class II- DNA transponsons
Define mutagens
Any physical, chemical or biological agent that raises the frequency of mutations above the spontaneous rate
What enzymes do Transposable elements use?
Transposase enzymes
How does Class I transposable elements use the copy + paste mechanism?
First transcription with a RNA intermediary then reverse transcription with a DNA intermediary and then integration.
How does Class II transposable elements use the copy + paste mechanism?
Excision with DNA intermediary then integration
Transposons are common in the genome- why?
They are destructive but also crucial for evolution for the traits in mammals and humans
Name 3 examples of diseases caused by transposons
Vision
Starch digestion
Memory evolution
What is the human mutation rate?
How does this compare to other organisms ?
1 mutations per 1 BILLION bps in humans
LOWEST mutation rate in any organism
