UNE Genetics Final Exam Questions
and All Correct Answers.
Central Dogma - Answer DNA -> RNA -> Protein, aka dna transcription (DNA to RNA) and
translation (RNA to proteins)
Structure of DNA - Answer Nitrogenous base, pentose sugar (deoxyribose, one less -OH
group than ribose), and a phosphate group
Purine base - Answer Adenine and Guanine
Pyrimidine base - Answer thymine, cytosine, and uracil
Structure of RNA - Answer Ribose sugar, nitogenous bases (uracil instead of thymine), and
phosphate group
Types of RNA - Answer rRNA, mRNA, tRNA
Evidence favoring DNA as genetic material - Answer Grifith's transformation experiment;
Avery, MacLeod, and McCarty; Hershey and Chase
Hershey and Chase - Answer concluded that the genetic material of the bacteriophage was
DNA, not protein. Used bacteriophages to infect E Coli with marker isotopes to confirm DNA
transfer
4 features of DNA replication - Answer semiconservative, bidirectional, continuous, and
discontinuous
Classes of mutations - Answer point mutations (change in one nucleotide)- missense; new
amino acid is coded, nonsense; codes for stop codon, or silent; codes for the same amino acid.
Alternately, transition (purine replaces purine and vice versa) or trasversion (purine replaces
pyrimidine and vice versa). Frameshift (addition or deletion altering future codons). Null (loss of
function), supressor (inter (other genes) or intragenic (same gene, complementation))
Parental age and mutations - Answer Paternal age is associated with an increase in
mutations (2+ every year)
Luria-Delbruck fluctuation test - Answer Demonstrated mutations are not adaptive but occur
spontaneously and randomly
, tautomeric shift - Answer a spontaneous mutation that involves a temporary change in a
base structure to occur at the moment DNA polymerase is passing through this specific base.
pyrimidines are usually in the keto form (and switch to enol), while purines are usually in amino
form (and switch to imino). this creates AG and CT base pairings.
depurination and deamination - Answer most common cause of spontaneous mutation- loss
of a nitrogenous base (often a purine) and amino group converting to a keto group respectively
Proofreading and Repairing DNA - Answer DNA polymerases proofread newly made DNA,
replacing any incorrect nucleotides
In mismatch repair of DNA, repair enzymes correct errors in base pairing
DNA can be damaged by exposure to harmful chemical or physical agents such as cigarette
smoke and X-rays; it can also undergo spontaneous changes
In nucleotide excision repair, a nuclease cuts out and replaces damaged stretches of DNA
Postreplication repair - Answer responds after damaged DNA has escaped repair and has
failed to be completely replicated
Ames Test - Answer A procedure using bacteria to identify potential carcinogens- preliminary
way to assess mutagenicity
Transposons - Answer (jumping genes) short strands of DNA capable of moving from one
location to another within a cell's genetic material
retrotransposons need rna intermediate, DNA transposons do not
Nonionizing v ionizing radiation - Answer UV is nonionizing, forms pyrimidine dimers (distort
DNA and inhibit normal replication). X rays, gamma rays, and cosmic rays aew ionizing (more
energetic, highly penetrating). Forms free radicals that alter base structure, break
phosphodiester bonds, and form chromosomal aberrations.
Epigenetics - Answer the study of environmental influences on gene expression that occur
without a DNA change. 1. reversible methylation, 2. chromatin remodeling, and 3. noncoding
RNA
DNA methylation - Answer Adding methyl group to nitrogenous base. Occurs after
replication and transcriptionally silences gene by blocking binding site
and All Correct Answers.
Central Dogma - Answer DNA -> RNA -> Protein, aka dna transcription (DNA to RNA) and
translation (RNA to proteins)
Structure of DNA - Answer Nitrogenous base, pentose sugar (deoxyribose, one less -OH
group than ribose), and a phosphate group
Purine base - Answer Adenine and Guanine
Pyrimidine base - Answer thymine, cytosine, and uracil
Structure of RNA - Answer Ribose sugar, nitogenous bases (uracil instead of thymine), and
phosphate group
Types of RNA - Answer rRNA, mRNA, tRNA
Evidence favoring DNA as genetic material - Answer Grifith's transformation experiment;
Avery, MacLeod, and McCarty; Hershey and Chase
Hershey and Chase - Answer concluded that the genetic material of the bacteriophage was
DNA, not protein. Used bacteriophages to infect E Coli with marker isotopes to confirm DNA
transfer
4 features of DNA replication - Answer semiconservative, bidirectional, continuous, and
discontinuous
Classes of mutations - Answer point mutations (change in one nucleotide)- missense; new
amino acid is coded, nonsense; codes for stop codon, or silent; codes for the same amino acid.
Alternately, transition (purine replaces purine and vice versa) or trasversion (purine replaces
pyrimidine and vice versa). Frameshift (addition or deletion altering future codons). Null (loss of
function), supressor (inter (other genes) or intragenic (same gene, complementation))
Parental age and mutations - Answer Paternal age is associated with an increase in
mutations (2+ every year)
Luria-Delbruck fluctuation test - Answer Demonstrated mutations are not adaptive but occur
spontaneously and randomly
, tautomeric shift - Answer a spontaneous mutation that involves a temporary change in a
base structure to occur at the moment DNA polymerase is passing through this specific base.
pyrimidines are usually in the keto form (and switch to enol), while purines are usually in amino
form (and switch to imino). this creates AG and CT base pairings.
depurination and deamination - Answer most common cause of spontaneous mutation- loss
of a nitrogenous base (often a purine) and amino group converting to a keto group respectively
Proofreading and Repairing DNA - Answer DNA polymerases proofread newly made DNA,
replacing any incorrect nucleotides
In mismatch repair of DNA, repair enzymes correct errors in base pairing
DNA can be damaged by exposure to harmful chemical or physical agents such as cigarette
smoke and X-rays; it can also undergo spontaneous changes
In nucleotide excision repair, a nuclease cuts out and replaces damaged stretches of DNA
Postreplication repair - Answer responds after damaged DNA has escaped repair and has
failed to be completely replicated
Ames Test - Answer A procedure using bacteria to identify potential carcinogens- preliminary
way to assess mutagenicity
Transposons - Answer (jumping genes) short strands of DNA capable of moving from one
location to another within a cell's genetic material
retrotransposons need rna intermediate, DNA transposons do not
Nonionizing v ionizing radiation - Answer UV is nonionizing, forms pyrimidine dimers (distort
DNA and inhibit normal replication). X rays, gamma rays, and cosmic rays aew ionizing (more
energetic, highly penetrating). Forms free radicals that alter base structure, break
phosphodiester bonds, and form chromosomal aberrations.
Epigenetics - Answer the study of environmental influences on gene expression that occur
without a DNA change. 1. reversible methylation, 2. chromatin remodeling, and 3. noncoding
RNA
DNA methylation - Answer Adding methyl group to nitrogenous base. Occurs after
replication and transcriptionally silences gene by blocking binding site
