MMCB EXAM LATEST UPDATE
DNA mutation def - ANSWER A permanent change in the DNA sequence that may be
transmitted to subsequent generations. It consists of an alteration of single base units in
DNA, or by the deletion, insertion, or rearrangement of larger sections of genes or
chromosomes
Somatic mutations def - ANSWER occur in a single body cell and cannot be inherited
(only tissues derived from mutated cell are affected
Germline mutation def - ANSWER occur in gametes, can be passed onto offspring
De novo mutations def - ANSWER GERMLINE mutations that are present in most cells of
an individual but not present in the majority of its parents' cells. Thereby, de novo
mutations are the mutations that were introduced in the germline during the course of
one generation
Genomic reshuffling - ANSWER Rearrangement of large DNA chunks, causing changes
gene positions on a chromosome
Regions of SYNTENY - ANSWER Regions in which the order of genes is conserved. They
can shrink and rearrange but the order remains the same. Derive from a common
ancestor.
C-value paradox - ANSWER There is a lack of correlation between genome(DNA) size
and the biological complexity of an organism
Pervasive DNA duplication - ANSWER Majority of bases is associated with at least one
primary transcript
Gene family - ANSWER A group of genes with related functions
Have structure and sequence similarities
Derive from the successive DUPLICATIONS of a COMMON ANCESTOR through
generations
Orthologs - ANSWER Homologous genes that are in different species. Descend from a
common ancestor
ORTO- SEPARATI
Paralogs - ANSWER Closely related genes within a same species.
Accumulation of mutation causes them to differentiate a bit.
PARA- non sono SEPARATI
, Pseudogenes - ANSWER Defective copies of genes, deriving from duplications (and
mutations right after) or from retrotransposition
Non processed pseudogenes - ANSWER Arise as a result of gene duplication and
subsequent inactivation by mutation
Contain introns
Processed pseudogenes - ANSWER Arise from retrotransposition (reverse transcription
of RNA to DNA).
Don-r contain introns.
REVERSE PSEUDOGENES - ANSWER Type of processed pseudogenes.
Derive from the activity of reverse-transcriptase (from LINE1 elements).
Tandem duplication - ANSWER Duplication of a chromosome segment that is adjacent to
the original segment.
- Happens due to crossing over between mis-aligned chromatids(homologous or sister)
- One chromosome with gene duplication, another one with no gene.
Transposable elements - ANSWER stretches of DNA that can move from one location to
another within the genome. Within/between chromosomes.
Retrotransposons (Class I) - ANSWER Transposons that make RNA copies of
themselves, which are copied into DNA and inserted in the genome.
LINE
SINE
LTR
DNA Transposons (Class II) - ANSWER Mobile genetic elements that move without
making an RNA intermediate.
terminal inverted repeats (TIR) - ANSWER sequence of nucleotides followed
downstream by its reverse complement. *eg> TTACGnnnnnnnnnnCGTAA
transposase - ANSWER enzyme which recognizes host DNA and cuts and glues
transposons in and out of genome
autonomous retrotransposons - ANSWER Contain CDS (enzymes) for reverse
transcriptase
Non-autonomous transposons - ANSWER Transposons lacking some or all of the
enzymes or components required for their transposition but can still transpose in the
presence of an autonomous element in the same family
DNA mutation def - ANSWER A permanent change in the DNA sequence that may be
transmitted to subsequent generations. It consists of an alteration of single base units in
DNA, or by the deletion, insertion, or rearrangement of larger sections of genes or
chromosomes
Somatic mutations def - ANSWER occur in a single body cell and cannot be inherited
(only tissues derived from mutated cell are affected
Germline mutation def - ANSWER occur in gametes, can be passed onto offspring
De novo mutations def - ANSWER GERMLINE mutations that are present in most cells of
an individual but not present in the majority of its parents' cells. Thereby, de novo
mutations are the mutations that were introduced in the germline during the course of
one generation
Genomic reshuffling - ANSWER Rearrangement of large DNA chunks, causing changes
gene positions on a chromosome
Regions of SYNTENY - ANSWER Regions in which the order of genes is conserved. They
can shrink and rearrange but the order remains the same. Derive from a common
ancestor.
C-value paradox - ANSWER There is a lack of correlation between genome(DNA) size
and the biological complexity of an organism
Pervasive DNA duplication - ANSWER Majority of bases is associated with at least one
primary transcript
Gene family - ANSWER A group of genes with related functions
Have structure and sequence similarities
Derive from the successive DUPLICATIONS of a COMMON ANCESTOR through
generations
Orthologs - ANSWER Homologous genes that are in different species. Descend from a
common ancestor
ORTO- SEPARATI
Paralogs - ANSWER Closely related genes within a same species.
Accumulation of mutation causes them to differentiate a bit.
PARA- non sono SEPARATI
, Pseudogenes - ANSWER Defective copies of genes, deriving from duplications (and
mutations right after) or from retrotransposition
Non processed pseudogenes - ANSWER Arise as a result of gene duplication and
subsequent inactivation by mutation
Contain introns
Processed pseudogenes - ANSWER Arise from retrotransposition (reverse transcription
of RNA to DNA).
Don-r contain introns.
REVERSE PSEUDOGENES - ANSWER Type of processed pseudogenes.
Derive from the activity of reverse-transcriptase (from LINE1 elements).
Tandem duplication - ANSWER Duplication of a chromosome segment that is adjacent to
the original segment.
- Happens due to crossing over between mis-aligned chromatids(homologous or sister)
- One chromosome with gene duplication, another one with no gene.
Transposable elements - ANSWER stretches of DNA that can move from one location to
another within the genome. Within/between chromosomes.
Retrotransposons (Class I) - ANSWER Transposons that make RNA copies of
themselves, which are copied into DNA and inserted in the genome.
LINE
SINE
LTR
DNA Transposons (Class II) - ANSWER Mobile genetic elements that move without
making an RNA intermediate.
terminal inverted repeats (TIR) - ANSWER sequence of nucleotides followed
downstream by its reverse complement. *eg> TTACGnnnnnnnnnnCGTAA
transposase - ANSWER enzyme which recognizes host DNA and cuts and glues
transposons in and out of genome
autonomous retrotransposons - ANSWER Contain CDS (enzymes) for reverse
transcriptase
Non-autonomous transposons - ANSWER Transposons lacking some or all of the
enzymes or components required for their transposition but can still transpose in the
presence of an autonomous element in the same family
