Which property is not essential for the origin of life?
The need to store information
The need to duplicate information
The need to change information
The need to make proteins
The need to convert into favorable reactions
Why is it thought that ribozymes are likely to be a legacy from an ancestral RNA world?
They are more stable than RNAs
When they act, they require the presence of protein cofactors
They act without the participation of protein cofactors.
They can be made spontaneously without a DNA template.
They are made by proteins
What was probably the first carrier of genetic information in primitive organisms?
DNA that could self-replicate
Proteins
Polypeptides
RNA that could self-replicate
Lipids
________ can be used to purify transcription activator proteins
Gel mobility shift assays
DNA affinity chromatography
Centrifugation
DNA footprinting
ChIP assays
Sequence specific DNA binding proteins frequently have a region that binds in the major groove because:
It is smaller
It contains sequence specific information
The minor groove is not available
It is positively charged
It is negatively charged
The following secondary structures are known to specifically interact with DNA (select all that apply):
Alpha helix
Beta sheet
Unstructured loops
Double helix
What happens at the lac operon in the absence of glucose and presence of lactose?
No expression
Low expression
The lac repressor binds the promoter
High expression
The CAP protein doesn't bind to the promoter
Multiple binding sites for a repressor is advantageous because:
There are too many repressors in cells
DNA must be bent to allow transcription
Repressors are only active when bound to many sites at once
This increases the effective concentration of the repressor
Repressors need multiple binding sites to bind ligands
An operator is:
A protein
A protein binding site
The same as a promoter
A type of repressor
The start site for RNA synthesis
Mammalian x-chromosome inactivation:
Occurs only in humans
Prevents females from being mosaics
Is not necessary
Is necessary for dosage compensation
Only occurs in males
CpG islands are generally found in
Inactive genes
Introns
Exons
Promoters of constantly active genes
Promoters of rarely expressed genes
Deamination of methyl-cytosine:
Does not occur
Changes methyl-cytosine to thymine
Only occurs in the sequence CG
Results in genomic imprinting
Occurs only in expressed genes
Sex determination in drosophila is due to:
Riboswitches
Alternative splicing
Alternative 3' end cleavage
Localization of mRNA
Alternative translational initiation
Mirco RNAs (miRNAs):
Are the same as rRNAs
Are not encoded by the genome
Are found only in bacteria
Are involved in gene repression
Are part of ribosomes
Attenuation involves regulation of:
Translation
Replication
Recombination
Transcription
Proteolysis
Ion exchange chromatography separates:
Proteins, based on size
Proteins, based on surface charge
Proteins, based on source
FRET is used to study:
Protein structure
Protein molecular weight
Protein/protein interaction
Protein sequence
Protein denaturation
SDS is used in protein gels to (select all that apply)...
Make glassware clean up easier
Help denature proteins
To create a uniform mass/charge ratio
To reduce disulfide bonds
DNA libraries are used to bank (select all that apply):
Genomic DNA
RNA
cDNA
Artificial chromosomes
Dideoxy nucleotides are used in DNA sequences to:
Denature the DNA
Hybridize the DNA
Chain terminate the DNA
Elongate the DNA
Transcribe the DNA
Hybridization of nucleic acids refers to:
A renaturation technique
An electrophoretic technique
A cloning technique
A forensic technique
A purification technique