Exam 4: How do Genes work? Flashcards
How does UV light damage DNA?
It causes thymine dimers to form, which makes kinks in the DNA strand
What are the three ways cancer occurs?
- Random mutations
- Inherited mutations
- Viral infections
What is cancer in 3 words?
Accumulation of mutations
What is the sequence of events in RNA processing?
DNA –> pre-mRNA –> mRNA –> Protein
What process converts DNA to RNA?
Transcription
What process converts RNA to Protein?
Translation
Differences in _______ may cause differences in phenotype
Genotype
How many bases are in a codon?
A group of three bases
Genetic code is redundant - what does that mean?
All but two amino acids encoded by >1 codon
Genetic code is non-overlapping - what does that mean?
Nucleotides belong to only one codon
Genetic code is comma-free - what does that mean?
The codons are read consecutively
Genetic code is conservative - what does that mean?
Codons for the same amino acids are similar
What is the start codon?
AUG
What are the stop codons?
UAG, UAA, UGA
Genetic code is nearly universal - what does that mean?
Codons have the same meaning in all organisms
What is another name for the nontemplate strand?
The coding strand
What is another name for the template strand?
The non-coding strand
What is the ultimate source of all genetic variation?
Mutations
How are mutations good? Bad?
Good: source of genetic variation for evolution
Bad: can cause diseases
Mutation in the hemoglobin-beta gene results in what disease?
Sickle cell disease
In sickle cell disease, glutamic acid is replaced by which amino acid?
Valine
What four things do the effects of mutation on phenotype depend on?
Cell type, when in the life cycle, dominance, type of mutation
What are the three types of mutations?
- Point mutations
- Frameshift mutations
- Chromosome-level mutations
Which mutation results from a single-base change?
Point mutation
