GN 301 EXAM 1 STUDY GUIDE |
2025/2026 LATEST UPDATTE |WITH
CORRECT QUESTION AND ANSWERS
Mutation - answers a change in the genetic material (DNA)
-most are recessive
Good mutation example - answers sickle cell anemia (malaria)
Bad mutation example - answers somatic mutation can cause cancer
Point mutation - answers substitution of one base pair for another
Transition - answers type of point mutation of a purine to purine or pyrimidine to a
pyrimidine
Purine - answers A and G
Pyrimidines - answers Cytosine and Thymine
Point mutation example (2) - answers Hemoglobin (half on beta and half on alpha)
Sickle Cell anemia
- best to be a carrier to fight malaria and live; no SC trait means you can easily get
malaria; both recessive means you have all sickle cells which cant carry oxygen well
frameshift mutation - answers insertion or deletion of a base pair; alters reading frame
from the altered codon to end of protein
Cystic Fibrosis (mutation/disorder description) - answers - mutation in CFTR Gene on
chromosome 7
- 2/3 of world and 90% due to deletion of 3 pairs (1 codon)
- In Jewish population nonsense mutation
Tay-Sachs disease - answers -lysosome break down materials
-fatty substance build up in the brain
- 4 base pairs insertion in exon 11
Disorders involving Trinucleotide Repeats - answers Huntington's
Fragile X syndrome (CGG on X chrom)
- Long chin bone disease
Anticipation - answers disorders present earlier and/or are more severe in later
generations
, Nonsense - answers protein stops early
Missense/nonsynonymous - answers different codon and different amino acid so it is a
different protein (Point Mutations)
Silent/Synonymous - answers different codon; same amino acid in protein (point
mutation)
Rate of spontaneous mutation - answers 1/100,000 per gene per cell
- 1/5 of gamete will have a mutation somewhere
Mutagen - answers agent that raises rate of mutation above spontaneous rate
- example: radiation, UV light, xray
Ames test - answers A procedure using bacteria to identify potential carcinogens;
determines which chemical causes most mutations
Effects of UV - answers mutation caused is pyrimidine dimer (mainly thymine, changes
DNA Shape with covalent bond)
Xeroderma pigmentosum
- defected repair mechanism to UV
- Causes sensitivity to light and high risk of skin cancer
Radiation - answers Average person exposed to 6.2 mSV/yr (From all sources)
- 3mSV because of earth
LD50/60 - answers dose which 50% of people die within 60 days (4.5 SV is lethal dose)
Safety Standards - answers Max dose of radiation workers is 20mSV/yr
- over 5 years with max 50mSV/year
-Pregnancy 5mSV/year
Hereditary - answers Transmissible from cell to cell (or parent to cell)
Congenital - answers present at birth
Phenocopy - answers condition resulting from environmental factors that mimics genetic
conditions (vitamin D efficiency)
Carcinogen - answers physical or chemical agent that causes cancer (ex: radiation and
tobacco)
Teratogen - answers physical or chemical agent that causes birth defects
- change in DNA expression
Fetal Alcohol Syndrome
- Congenital malformation
2025/2026 LATEST UPDATTE |WITH
CORRECT QUESTION AND ANSWERS
Mutation - answers a change in the genetic material (DNA)
-most are recessive
Good mutation example - answers sickle cell anemia (malaria)
Bad mutation example - answers somatic mutation can cause cancer
Point mutation - answers substitution of one base pair for another
Transition - answers type of point mutation of a purine to purine or pyrimidine to a
pyrimidine
Purine - answers A and G
Pyrimidines - answers Cytosine and Thymine
Point mutation example (2) - answers Hemoglobin (half on beta and half on alpha)
Sickle Cell anemia
- best to be a carrier to fight malaria and live; no SC trait means you can easily get
malaria; both recessive means you have all sickle cells which cant carry oxygen well
frameshift mutation - answers insertion or deletion of a base pair; alters reading frame
from the altered codon to end of protein
Cystic Fibrosis (mutation/disorder description) - answers - mutation in CFTR Gene on
chromosome 7
- 2/3 of world and 90% due to deletion of 3 pairs (1 codon)
- In Jewish population nonsense mutation
Tay-Sachs disease - answers -lysosome break down materials
-fatty substance build up in the brain
- 4 base pairs insertion in exon 11
Disorders involving Trinucleotide Repeats - answers Huntington's
Fragile X syndrome (CGG on X chrom)
- Long chin bone disease
Anticipation - answers disorders present earlier and/or are more severe in later
generations
, Nonsense - answers protein stops early
Missense/nonsynonymous - answers different codon and different amino acid so it is a
different protein (Point Mutations)
Silent/Synonymous - answers different codon; same amino acid in protein (point
mutation)
Rate of spontaneous mutation - answers 1/100,000 per gene per cell
- 1/5 of gamete will have a mutation somewhere
Mutagen - answers agent that raises rate of mutation above spontaneous rate
- example: radiation, UV light, xray
Ames test - answers A procedure using bacteria to identify potential carcinogens;
determines which chemical causes most mutations
Effects of UV - answers mutation caused is pyrimidine dimer (mainly thymine, changes
DNA Shape with covalent bond)
Xeroderma pigmentosum
- defected repair mechanism to UV
- Causes sensitivity to light and high risk of skin cancer
Radiation - answers Average person exposed to 6.2 mSV/yr (From all sources)
- 3mSV because of earth
LD50/60 - answers dose which 50% of people die within 60 days (4.5 SV is lethal dose)
Safety Standards - answers Max dose of radiation workers is 20mSV/yr
- over 5 years with max 50mSV/year
-Pregnancy 5mSV/year
Hereditary - answers Transmissible from cell to cell (or parent to cell)
Congenital - answers present at birth
Phenocopy - answers condition resulting from environmental factors that mimics genetic
conditions (vitamin D efficiency)
Carcinogen - answers physical or chemical agent that causes cancer (ex: radiation and
tobacco)
Teratogen - answers physical or chemical agent that causes birth defects
- change in DNA expression
Fetal Alcohol Syndrome
- Congenital malformation
