GENETICS FINAL EXAM STUDY GUIDE PCB 3063 20

GENETICS FINAL EXAM STUDY GUIDE PCB 3063 -20 FALL 0001 WITH DR. BAYER

***DISCLAIMER*** • THIS STUDY GUIDE WAS CREATED BY ME (EMILY) AND SHOULD NOT BE THE ONLY RESOURCE YOU USE TO STUDY FOR YOUR FINAL EXAM. PLEASE MAKE SURE YOU ARE ALWAYS DOUBLE CHECKING MY WORK WITH RESOURCES THE PROFESSOR PROVIDES – POWERPOINTS, LECTURE NOTES, TEXTBOOK, ETC. • THIS STUDY GUIDE ONLY COVERS THE VERY BASICS OF EACH CHAPTER. IT HIGHLIGHTS/FOCUSES ON THE OVERALL CONCEPTS. IT WOULD BE A GOOD IDEA TO HAVE THE POWERPOINTS OPEN/YOUR NOTES TO ADD IN DETAIL WHERE YOU FEEL NECESSARY! • THIS STUDY GUIDE DOES NOT COVER CHAPTERS 17 AND 19 (THEY ARE HEAVILY DEFINITION BASED)

CHAPTER 1: WHAT IS GENETICS? • THE STUDY OF HEREDITY AND VARIATION

WHAT IS DNA? • Deoxyribonucleic acid • What are some facts of DNA? • Double-stranded • Helical • Composed of nucleotides • Held together by hydrogen bonds

WHAT IS THE CENTRAL DOGMA? • DNA RNA PROTEIN • WHAT PROCESS GOES FROM DNA TO RNA? • TRANSCRIPTION • WHAT PROCESS GOES FROM RNA TO PROTEINS? • TRANSLATION

TERMINOLOGY • WHAT IS A CHROMOSOME? • DNA + PROTEINS • HOW ARE THEY IN EUKARYOTES? • MULTIPLE • ROD-LIKE • IN THE NUCLEUS • HOW ARE THEY IN PROKARYOTES? • SINGLE • CIRCULAR • NUCLEOID REGION • GENOTYPE: • THE SPECIFIC ALLELE AN INDIVIDUAL POSSESSES AT A SPECIFIC LOCI • PHENOTYPE: • HOW THE GENOTYPE IS EXPRESSED

TERMINOLOGY CONT’D. • DOMINANT: • THE ALLELE EXPRESSED IN A HETEROZYGOTE • RECESSIVE: • THE ALLELE MASKED IN A HETEROZYGOTE • HOMOZYGOTE: • IDENTICAL ALLELES OF A GENE • HETEROZYGOTE: • TWO DIFFERENT ALLELES OF A GENE

EUKARYOTIC CELL REPRODUCTION • WHAT IS A SOMATIC CELL? • WHAT PROCESS DO THEY UNDERGO? • MITOSIS ONLY • WHAT IS A GERM CELL? • WHAT IS ANOTHER NAME FOR THEM? • SEX CELL • WHAT PROCESS DO THEY UNDERGO? • MEIOSIS AND MITOSIS • WHAT IS HAPLOID? • CELLS WITH ONLY 1 COPY OF EACH CHROMOSOME • WHAT IS DIPLOID? • CELLS WITH 2 COPIES OF EACH CHROMOSOME • A DUPLICATED CHROMOSOME IS CALLED: • SISTER CHROMATIDS • TWO PAIRS OF CHROMOSOMES ARE CALLED • HOMOLOGOUS CHROMOSOMES

CELL CYCLE • What is interphase? • G 1, S, G 2, G 0 • What happens during G 1? • Growth, prepare for DNA replication • What happens during S phase? • DNA replication (chromatid formation) • What happens during G 2? • Growth, prepare for division • What happens during G 0? • Cell is performing its function NO DIVISON

WHAT ARE THE PHASES OF MITOSIS? • PROPHASE • CHROMOSOMES CONDENSE • PROMETAPHASE • NUCLEAR MEMBRANE DISSOLVES SPINDLE MICROTUBULES ATTACH • METAPHASE • CHROMOSOMES LINE UP AT THE METAPHASE PLATE • ANAPHASE • SISTER CHROMATIDS SEPARATE AND MOVE TO OPPOSITE ENDS OF THE POLE • TELOPHASE • CHROMOSOMES ARRIVES AT POLES • NUCLEAR MEMBRANE REFORMS • CYTOKINESIS

MITOSIS VS MEIOSIS • IN MITOSIS, ONLY SISTER CHROMATIDS • IN MEIOSIS, HOMOLOGOUS CHROMOSOME • WHAT HAPPENS IN PROPHASE I OF MEIOSIS? • CROSSING OVER! • WHERE DOES IT OCCUR? • CHIASMATA • BETWEEN WHICH CHROMOSOMES? • NON-SISTER CHROMATIDS • WHAT PROCESS RESTORES THE # OF CHROMOSOMES? • FERTILIZATION

CHAPTER 3 WHAT WERE THE ADVANTAGES OF STUDYING PEA PLANTS? • BENEFITS: • SHORT GENERATION TIME, EASY TO CONTROL, MANY PUREBRED VARIETIES • WHAT IS A MONOHYBRID EXPERIMENT? • FOLLOWING ONLY 1 CHARACTERISTIC • WHAT IS A DIHYBRID EXPERIMENT? • FOLLOWING 2 CHARACTERISTICS/TRAITS • WHAT ARE TRUE BREEDERS? • HOMOZYGOUS FOR A TRAIT

WHAT WERE MENDEL'S 4 MAJOR CONCLUSIONS? 1) ALTERNATIVE VERSIONS OF GENETIC FACTORS ARE ALLELES 1) AN ORGANISM HAS HOW MANY ALLELES FOR A TRAIT (GENERALLY)? 1) 2! 2) LAW OF SEGREGATION: 1) THE ALLELES SEPARATE WHEN GAMETES FORM ONE ALLELE GOES INTO EACH GAMETE 3) LAW OF INDEPENDENT ASSORTMENT: 1) WHEN TWO ALLELES SEPARATE, THEY SEPARATE WITH EQUAL PROBABILITY 4) IF TWO ALLELES DIFFER, WHICH ALLELE DETERMINES THE APPEARANCE? 1) DOMINANT!

RULES OF PROBABILITY • RULE OF MULTIPLICATION: • RULE OF ADDITION: • THE PROBABILITY THAT 2 OR MORE INDEPENDENT EVENTS WILL OCCUR TOGETHER IS THE PRODUCT OF THEIR INDIVIDUAL PROBABILITIES • THE PROBABILITY THAT EITHER 1 OF 2 OR MORE MUTUALLY EXCLUSIVE EVENTS WILL OCCUR IS THE SUM OF THEIR INDIVIDUAL PROBABILITIES • EACH EVENT IS INDEPENDENT OF EACHOTHER

CHAPTER 4 SEX CHROMOSOMES • WHAT CHROMOSOMES DO EACH GENDER HAVE: • FEMALE: XX • MALE: XY • WHICH CHROMOSOMES CARRIES A MAJORITY OF THE NECESSARY PROTEINS? • X-CHROMOSOME • WHICH CHROMOSOME CARRIES THE SRY GENE? • Y-CHROMOSOME • WHAT IS THE FUNCTION OF THE SRY GENE? • SEX-DETERMINING REGION DETERMINES MALE SEX

ANEUPLOIDY • WHAT ARE ANEUPLODIES? • ABNORMAL # OF CHROMOSOMES IN A CELL • HOW DO THEY OCCUR AND WHERE? • NONDISJUNCTION: FAILURE OF CHROMOSOMES TO SEPARATE PROPERLY DURING MEIOSIS • WHAT ARE THE TWO TYPES? • MONOSOMY: • LOSE CHROMSOME (2 N-1) • TRISOMY: • GAIN CHROMOSOME (2 N+1) • NAME SOME COMMON EXAMPLES • TURNER SYNDROME, KLEINFELTER’S SYNDROME, ETC. • **GO BACK AND MAKE SURE YOU HAVE A GENERAL IDEA OF EACH**

ANEUPLOIDIES CONT’D. • T/F: ANEUPLOIDIES ARE BETTER TOLERATED ON AUTOSOMES OVER SEX CHROMOSOMES • FALSE! ANEUPLOIDIES OF AUTOSOMES ARE DETRIMENTAL, WHEREAS THEY CAN BE FAIRLY COMPENSATED ON SEX CHROMOSOMES • WHAT IS X-INACTIVATION? • ONE X-CHROMOSOME ON BOTH MALES AND FEMALES REMAINS CONDENSED AND IS NOT EXPRESSED • WHAT IS THE INACTIVATED X-CHROMOSOME CALLED? • BARR BODY • CAN THE INACTIVATED X-CHROMOSOME EVER BECOME “UNACTIVATED”? • NO! THE SAME INACTIVATED X-CHROMOSOME IS CARRIED ON THROUGHOUT DIVISION

CHAPTER 5: TYPES OF DOMINANCE • COMPLETE DOMINANCE: • PHENOTYPE OF THE HETEROZYGOTE IS THE SAME AS THE PHENOTYPE OF ONE OF THE HOMOZYGOTES • INCOMPLETE DOMINANCE: • PHENOTYPE OF THE HETEROZYGOTE IS IN BETWEEN THE PHENOTYPES OF THE TWO HOMOZYGOTES • CODOMINANCE: • PHENOTYPE OF THE HETEROZYGOTE INCLUDES THE PHENOTYPES OF BOTH HOMOZYGOTES

WHEN SEX OF PARENT MATTERS • THE EXPRESSION OF SOME TRAITS, EVEN THOUGH THEY ARE NOT SEXLINKED, IS AFFECTED BY WHICH PARENT PASSED ON THE GENE • CAN YOU THINK OF SOME EXAMPLES? • CYTOPLASMIC INHERITANCE • PASSED ON ONLY FROM MOTHER • GENETIC MATERNAL EFFECT • THE PHENOTYPE OF THE OFFSPRING IS DETERMINED BY THE NUCLEAR GENOTYPE OF THE MOTHER

CHAPTER 6: INHERITANCE PATTERNS WHAT ARE THE 5 TYPES OF INHERITANCE PATTERNS? Autosomal Recessive! • AUTOSOMAL RECESSIVE • LOOK FOR SKIPPED GENERATIONS • AUTOSOMAL DOMINANT • SHOULD APPEAR IN EVERY GENERATION • SEX-LINKED RECESSIVE • LOOK FOR SKIPPED GENERATIONS • SEX-LINKED DOMINANT • SHOULD APPEAR IN EVERY GENERATION • Y-LINKED INHERITANCE • ONLY MALES AFFECTED **KNOW THE GENERAL CHARACTERISTICS OF EACH, BUT DON’T FOCUS TOO MUCH ON THESE

CHAPTER 7: GENETIC LINKAGE & RECOMBINATION • WHAT DOES IT MEAN FOR GENES TO BE LINKED? • PHYSICALLY LOCATED ON THE SAME CHROMOSOME • CAN WE USE THE FREQUENCY OF RECOMBINATION TO MAP GENE LOCI ALONG A CHROMOSOME? • MORE RECOMBINANT OFFSPRING = MORE _____ • CROSSOVER EVENTS! • THE ______ APART GENES ARE, THE ______ LIKELY THEY ARE TO CROSSOVER • FARTHER, MORE • WHAT IS THE HIGHEST RECOMBINATION FREQUENCY POSSIBLE? • 50% • WHY? • CROSSING OVER OCCURS BETWEEN 50% OF THE

CROSSING OVER AND VARYING DEGREES OF LINKAGE: • INDEPENDENT ASSORTMENT: • CROSSING OVER OCCURS HALF THE PROGENY IS RECOMBINANT, HALF IS • NOT • THESE GENES ARE NOT LINKED • COMPLETE LINKAGE: • ALL PROGENY ARE NONRECOMBINANT • NO CROSSING OVER OCCURS • LINKED, BUT CROSSING OVER STILL OCCURS: • CROSSING OVER OCCURS IN SOME CELLS, BUT NOT OTHERS • # OF RECOMBINANT PROGENY CANNOT EXCEED 50% GENES ARE UNLINKED FOR 2 REASONS: • NOT ON THE SAME CHROMOSOME • PHYSICALLY LOCATED ON THE SAME CHROMOSOME, BUT FAR ENOUGH APART FOR CROSSING OVER TO OCCUR

WHAT ARE DOUBLE CROSSOVER EVENTS? • TWO CROSSOVER EVENTS THAT DISPLACE THE MIDDLE GENE ON A CHROMOSOME

CHAPTER 8: CHROMOSOMAL VARIATION WHAT ARE THE TYPES OF CHROMOSOMAL REARRANGEMENTS? • DUPLICATION • DELETION • CHROMOSOME SEGMENT IS LOST • INVERSION • CHROMOSOME SEGMENT IS FLIPPED 180 DEGREES • TRANSLOCATION • SEGMENT MOVES TO A NEW LOCATION ON SAME OR HOMOLOGOUS CHROMOSOME • A SEGMENT IS DUPLICATED • WHAT HAPPENS TO THE DUPLICATED SEGMENT? • TANDEM: • ADJACENT TO ORIGINAL SEGMENT • DISPLACED: • LOCATED SOME DISTANCE AWAY FROM ORIGINAL SEGMENT • REVERSE: • DUPLICATED REGION IS INVERTED

PRACTICE TANDEM DUPLICATION! DUPLICATION INVERSION

CHAPTER 10: DNA • WHAT IS DNA COMPOSED OF? • NUCLEOTIDES (WHAT ARE THEY MADE OF? ) • PENTOSE SUGAR, PHOSPHATE GROUP, NITROGENOUS BASE • WHAT ARE CHARGRAFF’S RULES? • %A = %T AND %G = %C • WHAT WAS SIGNIFICANT ABOUT GRIFFITH’S EXPERIMENT? • DEMONSTRATED THAT GENETIC MATERIAL COULD BE TRANSFERRED BETWEEN BACTERIAL CELLS • WHAT WAS SIGNIFICANT ABOUT AVERY, MCLEOD, AND MCCARTY’S EXPERIMENT? • DEMONSTRATED THAT DNA WAS THE TRANSFORMING SUBSTANCE (NOT PROTEINS!) • WHAT IS SIGNIFICANT ABOUT HERSHEY & CHASE EXPERIMENT?

DNA CONT’D. • WHO WERE WILKINS AND FRANKLIN? • USE X-RAY DIFFRACTION TO STUDY THE STRUCTURE OF DNA • WHO WERE WATSON AND CRICK? • SOLVED THE STRUCTURE OF DNA • HOW DO BASES PAIR IN DNA? • A-T AND G-C

STRUCTURES OF DNA • PRIMARY • STRING OF NUCLEOTIDES • HOW ARE NUCLEOTIDES JOINED? • PHOSPHODIESTER BOND • SECONDARY • 2 POLYNUCLEOTIDE STRANDS FORMING A DOUBLE HELIX • HOW ARE THE STRANDS HELD TOGETHER? • HYDROGEN BONDS! • TERTIARY • PACKAGING INTO CHROMOSOMES

HALFWAY POINT HOW ARE WE ALL DOING? !

CHAPTER 11: CHROMOSOME STRUCTURE • WHAT DOES IT MEAN FOR DNA TO BE SUPERCOILED? • WINDING OR UNWINDING OF THE DOUBLE HELIX • POSITIVE SUPERCOIL: • OVER-ROTATED • NEGATIVE SUPERCOIL: • UNDER-ROTATED • WHAT ENZYME IS RESPONSIBLE FOR SUPERCOILING? • TOPOISOMERASE! • HOW ARE CHROMOSOMES DURING INTERPHASE? • LESS CONDENSED

CHROMATIN • WHAT IS CHROMATIN? • DNA COMPLEXED WITH HISTONES (PROTEINS) • EUCHROMATIN: • DEGREE OF CONDENSATION VARIES DEPENDING ON NECESSITY • HETEROCHROMATIN: • REMAINS RELATIVELY CONDENSED THROUGHOUT • EXAMPLES? TELOMERES, CENTROMERES, AND Y-CHROMOSOME • HOW MANY HISTONE PROTEINS COMPLEX WITH DNA? (CAN YOU NAME THEM? ) • 5 TYPES: H 1, H 2 A, H 2 B, H 3, AND H 4 • WHICH ARE A PART OF THE OCTET? • WHEN H 1 BINDS, NUCLEOSOME BECOMES CHROMATOSOME • HOW DO HISTONES INTERACT WITH DNA? • HISTONE HAS POSITIVELY CHARGED TAILS THAT BIND WITH THE NEGATIVE BACKBONE OF DNA

CHAPTER 12: DNA REPLICATION • DNA REPLICATES IN A ____________ MANNER • SEMI-CONSERVATIVE • WHAT ARE THE REQUIREMENTS FOR REPLICATION? • TEMPLATE OF SINGLE-STRANDED DNA • SUBSTRATES (DNTP’S) • ENZYMES • WHAT IS THE DIFFERENCE BETWEEN LEADING AND LAGGING STRAND? • LEADING STRAND: SAME DIRECTION AS SYNTHESIS • LAGGING STRAND: OPPOSITE DIRECTION AS SYNTHESIS

DNA REPLICATION ENZYMES (CAN YOU NAME THEM ALL? • INITIATOR PROTEINS: • BIND TO THE ORIGIN OF REPLICATION AND UNWIND A SMALL PORTION OF THE DNA (BUBBLE) • SINGLE-STRANDED BINDING PROTEINS: • ATTACH TO THE DNA TO PREVENT THE DOUBLE STRANDS FROM REFORMING • HELICASE: • BINDS TO THE REPLICATION FORK AND UNWINDS DNA 5’ 3’ • GYRASE: • RELIEVES STRAIN AHEAD OF THE REPLICATION FORK (ACTS AS A __________) • PRIMASE: • LAYS DOWN A SHORT STRETCH OF RNA NUCLEOTIDES (PRIMER) • WHY IS THIS IMPORTANT? • DNA POLYMERASE: • ADDS NUCLEOTIDES TO THE GROWING STRAND • DNA LIGASE: • SEALS THE NICK AT THE END

CHAPTER 13: TRANSCRIPTION • WHICH ENZYME IS RESPONSIBLE FOR TRANSCRIPTION? • RNA POLYMERASE • WHAT IS IT CALLED WITHOUT SIGMA FACTOR? WITH SIGMA FACTOR? • CORE ENZYME + SIGMA FACTOR = HOLOENZYME

STAGES OF TRANSCRIPTION • INITIATION • RNA POLYMERASE BINDS TO THE PROMOTER AND RECOGNIZES CONSENSUS SEQUENCES • WHAT ARE THE CONSENSUS SEQUENCES IN EUKARYOTES? BACTERIA? • EUKARYOTES: TATA BOX • BACTERIA: PRIBNOW BOX (-10) AND -35 • ELONGATION • NUCLEOTIDES ARE ADDED • TERMINATION • RHO-INDEPENDENT • HAIRPIN LOOP FORMS AND CAUSES DESTABILIZATION TERMINATION • RHO-DEPENDENT • RHO FACTOR BINDS TO RUT SITE AND CHEWS BACK THE RNA TOWARDS THE 3’ END

HOW DOES TRANSCRIPTION DIFFER IN BACTERIA AND EUKARYOTES?

CHAPTER 14: RNA PROCESSING • WHICH TYPE OF RNA UNDERGOES PROCESSING AND IN WHICH ORGANISM? • MRNA IN EUKARYOTES? (WHY)? • TRANSCRIPTION AND TRANSLATION OCCUR IN DIFFERENT LOCATIONS AND AT DIFFERENT TIMES • WHAT ARE THE 3 THINGS THAT HAPPEN DURING PROCESSING? • 5’ CAP ADDITION • SPLICING • WHAT ARE SPLICED? • INTRONS SPLICED OUT EXONS FUSED TOGETHER! • WHAT CARRIES OUT THE SPLICING? • SPLICEOSOME! • 3’ POLY (A) TAIL ADDITION

CHAPTER 15: TRANSLATION • WHAT IS TRANSLATION? • PROCESSING OF TAKING MRNA TO AMINO ACIDS (PROTEINS) • WHAT CARRIES OUT THE PROCESS OF TRANSLATION? • RIBOSOMES! • WHAT ARE THE STRUCTURE LEVELS OF PROTEIN? • PRIMARY: AMINO ACID SEQUENCE • SECONDARY: HYDROGEN BONDING BETWEEN THE PEPTIDE BACKBONE • TERTIARY: BONDS BETWEEN R-GROUPS FOLDING INTO A 3 D SHAPE • QUATERNARY: MULTIPLE TERTIARY STRUCTURES FORMING A FUNCTIONAL PROTEIN • HOW ARE AMINO ACIDS CODED? • CODONS! SETS OF 3 NUCLEOTIDES LOCATED ON THE MRNA

STAGES OF TRANSLATION • CHARGING: • WHAT MOLECULE CARRIES BRINGS THE AMINO ACID TO MRNA? • TRNA! • WHICH PART OF THE TRNA BINDS TO THE AMINO ACID AND WHICH PART BINDS TO THE MRNA? • ACCEPTOR ARM HAS AMINO ACID, ANTICODON RECOGNIZES CODON ON MRNA • INITIATION: • RIBOSOME BINDS TO THE __________ SEQUENCE • SHINE-DELGARNO SEQUENCE (BACTERIA) • WHICH SUBUNIT BINDS FIRST? • SMALL THEN LARGE! • ELONGATION: • CAN YOU DESCRIBE THE E, P, A SITES? • TERMINATION: • STOP CODON IS REACHED AND APPARATUS FALLS OFF

CHAPTER 16: CONTROL OF GENE EXPRESSION IN PROKARYOTES • WHAT IS AN OPERON? • A CLUSTER OF FUNCTIONALLY-RELATED GENES THAT SHARE A COMMON PROMOTER AND ARE TRANSCRIBED AS A UNIT • WHAT IS A REGULATORY GENE? • DNA SEQUENCE ENCODING A PRODUCT THAT AFFECTS THE OPERON FUNCTION (PRODUCES A REGULATOR PROTEIN), BUT IS NOT PART OF THE OPERON. • WHAT ARE THE TYPES OF TRANSCRIPTIONAL CONTROL? • NEGATIVE: REGULATORY PROTEIN IS A REPRESSOR • POSITIVE: REGULATORY PROTEIN IS AN ACTIVATOR • WHAT ARE THE TYPES OF OPERONS? • INDUCIBLE: NORMALLY OFF BUT CAN BE TURNED ON • REPRESSIBLE: NORMALLY ON BUT CAN BE TURNED OFF

INDUCIBLE OPERON

REPRESSIBLE OPERON

DESCRIBE THE LAC OPERON UNDER THE FOLLOWING CONDITIONS: • LACTOSE PRESENT • 1000 X INCREASE IN OPERON EXPRESSION • NO LACTOSE PRESENT • MINIMAL LEVEL OF EXPRESSION • GLUCOSE ONLY PRESENT • MINIMAL LEVEL OF EXPRESSION • GLUCOSE AND LACTOSE PRESENT • MINIMAL LEVEL OF EXPRESSION WHY DOES THE PRESENCE OF GLUCOSE DECREASE LAC OPERON EXPRESSION?

CHAPTER 18: GENE MUTATIONS AND DNA REPAIR • WHAT ARE THE TYPES OF GENE MUTATIONS? • SUBSTITUTION • TRANSITION: PURINE TO PURINE OR PYRIMIDINE TO PYRIMIDINE • TRANSVERSION: PURINE TO PYRIMIDINE OR VICE VERSE • DELETION/INSERTION • WHAT ARE THE PHENOTYPIC EFFECTS OF THOSE MUTATIONS? • MISSENSE • CODES FOR A DIFFERENT AMINO ACID • NONSENSE • CODES FOR A STOP CODON • SILENT • CODES FOR THE SAME AMINO ACID • NEUTRAL • CODES FOR A CHEMICALLY SIMILAR AMINO ACID

THE END!! • THERE IS A STUDY GUIDE WITH MUCH MORE DETAIL ON CHAPTERS 16 -18 IF YOU WOULD LIKE TO REFERENCE THOSE • ADDITIONALLY, THE WORDPRESS SITE HAS STUDY GUIDES FROM THE FIRST TWO EXAMS WITH MORE IN-DEPTH CONTENT • THERE IS LOTS OF PRACTICE RESOURCES AND NOTES FROM PAST SI SESSIONS • PLEASE DON’T FORGET ABOUT THE SAPLING AND END OF CHAPTER PROBLEMS YOU HAVE FOR PRACTICE!! • WORDPRESS WEBSITE: HTTPS: //UCFSI. WORDPRESS. COM/GENETICS-WITHEMILY/ • BEST OF LUCK TO YOU ALL!