Study Guide for Unit 4: Genetics
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Chapter 12: The Chromosomal Basis of Inheritance
o Chromosome theory of inheritance and Mendel
o Wild type
o Sex-linked genes and sex chromosomes
 X-linked genes- what kind of implications?
o X-inactivation
 Barr body
 Be able to figure out what a heterozygous female would look like using Punnett
square and x-inactivation idea.
o Linked genes
 How do they deviate from Mendel
 Genetic recombination
 Linked vs. unlinked
 Parental types
 Recombinant types (recombinants)
 Crossing over
 Why is variation important?
 Calculation of recombination frequency and what it tells us
 Recombination frequency and map units
 Linkage map
 Chi-square for linked or unlinked hypothesis
o Chromosomal alterations
 Nondisjunction
 Aneuploidy
 Monosomic (monosomy)
 Trisomic (trisomy)
 How does it happen?
 Polyploidy
 Deletions, inversions, translocations, duplications
 Be able to identify and explain these!!!
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Chapter 13: The Molecular Basis of Inheritance
o Explain the evidence for DNA being the molecule of inheritance
 Transformation
 Bacteriophages
o DNA structure
 Double helix
 Anti-parallel
 3’ vs. 5’
 Components of DNA
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Nucleotides
o Phosphate group, deoxyribose sugar, and nitrogenous bases
Nitrogenous bases
o Adenine, Thymine, Guanine, Cytosine
 Which bond with which
 Why do they bond?
 What holds them together?
 Which pair bonding is the strongest? What types of
organisms might you see a high number of these?
 Purines vs. Pyrimidines
Sugar-phosphate backbone
o Charge
o Bonding
Van der Waals bonding
Why are the nitrogenous bases on the inside and the sugar and
phosphate groups on the outside?
DNA replication
 Semi-conservative replication
 Eukaryotic vs. prokaryotic chromosomes
 Origin of replication
 Replication fork
 Enzymes!
 Helicase
 DNA polymerase
o In which direction is DNA read? Replicated?
 Ligase
 Primase
 Topoisomerase
 SSBPs
 Be able to draw replication with major players
 Leading strand
 Lagging strand
 Okazaki fragments and ligase
 Proof-reading and repairing DNA
 Mismatch repair
 How often do mutations occur (relatively)?
 Evolutionary significance of altered DNA
 Replicating the ends of DNA molecules
 Why does it matter?
 Why does it happen?
 Telomeres
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DNA winding
 Histones
 Chromatin and chromosomes
 How are histones attracted to DNA?
 Nucleosome
o Genetic engineering
 Ethical concerns
 Plasmids and cloning vectors
 Nucleoid
 Recombinant DNA
 Gene cloning- why do you have to do it?
 Restriction site
 Restriction enzyme
 Restriction fragments
 Process of recombining DNA
 Sticky end
 Polymerase chain reaction
 Gel electrophoresis
Chapter 14: Gene Expression: From Gene to Protein
o Gene expression
o How is DNA different than RNA?
o Central Dogma
o Transcription and translation
 What organisms do these processes occur in?
o Transcription
 DNA to RNA
 Which nitrogenous base is missing and which one replaces it?
 Messenger RNA
 Be able to transcribe a provided DNA template
 RNA polymerase
 Direction of synthesis
 Promoter
 Terminator
 Transcription factors
 TATA box
 Where does transcription happen in eukaryotes?
 Why?
 Template strand
 RNA strand produced is complementary not identical to DNA template strand
o Alteration of RNA produced by transcription
 5’ cap- why important?
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Poly-A tail- why important?
RNA splicing- why?
 Introns vs. exons
o Translation
 mRNA to protein (polypeptide)
 Where does translation occur?
 Explain the process- initiation, elongation, and termination
 mRNA, tRNA, rRNA- what does each do?
 tRNA and anticodons
 Codons
 How many nucleotides in a codon? Why?
 Be able to translate a provided mRNA sequence into amino acids using a codon
chart
 Ribosomes
 P, A, and E site
 Protein-folding and post-translational modifications
o Evolutionary significance of genetic code
o Mutations of nucleotides
 Point mutations
 Substitution
 Silent mutation
 Missense mutation
 Nonsense mutation
 Insertions and deletions
 Frameshift mutation
 Mutagens
Transformation lab
o Revisit terms from 13.4 (ex. Restriction enzyme, restriction fragment, plasmid, etc) and
apply them to the lab
o Understand the process- what were we trying to see?
o DO NOT NEED TO KNOW THE PRECISE METHODS (ex. Amounts, concentrations, enzyme
name).
o What is transformation?